EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM

DRAFT prEN 13262 June 2018 ICS 45.040 Will supersede EN 13262:2004+A2:2011

English Version Railway applications - Wheelsets and bogies - Wheels - Product requirements Applications ferroviaires - Essieux montés et bogies - Roues - Prescriptions pour le produit Bahnanwendungen - Radsätze und Drehgestelle - Räder - Produktanforderungen This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 256. If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to provide supporting documentation. Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION C O M I T É E U R O P É E N D E N O R M A L I S A T I O N E U R O P Ä I S C H E S K O M I T E E F Ü R N O R M U N G CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2018 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. prEN 13262:2018 E

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Contents Page

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms and definitions ................................................................................................................................... 7

4 Product definition ........................................................................................................................................... 7 4.1 Chemical composition ................................................................................................................................... 7 4.2 Mechanical characteristics .......................................................................................................................... 8 4.3 Heat treatment homogeneity ................................................................................................................... 15 4.4 Material cleanliness .................................................................................................................................... 16 4.5 Residual stresses .......................................................................................................................................... 21 4.6 Surface characteristics ............................................................................................................................... 22 4.7 Geometric tolerances .................................................................................................................................. 24 4.8 Static imbalance ............................................................................................................................................ 28 4.9 Protection against corrosion ................................................................................................................... 28 4.10 Manufacturer's marking ............................................................................................................................ 28

5 The manufacturer’s mark identifies the unique reference for quality and characteristics of the component. The manufacturer’s mark shall be put at the final manufacturing step prior to delivery. Product qualification ....................................................... 29

6 Product delivery conditions ..................................................................................................................... 29

7 Advices to choose the steel grade ........................................................................................................... 29

Annex A (normative) Assessment process for acceptance of new materials ...................................... 30 A.1 General ............................................................................................................................................................. 30 A.2 First step: Characterization of a new steel grade ............................................................................. 30 A.3 Second step: Service testing period ....................................................................................................... 30 A.4 Third step: Report ........................................................................................................................................ 31

Annex B (informative) Examples of benches for fatigue tests .................................................................. 32 B.1 Test piece ........................................................................................................................................................ 32 B.2 First test method .......................................................................................................................................... 32 B.3 Second test method ..................................................................................................................................... 33 B.4 Third test method ........................................................................................................................................ 34

Annex C (informative) Strain gauge method for determining the variations of circumferential residual stresses located deep under the tread (destructive method) .... 36

C.1 Principle of the method ............................................................................................................................. 36 C.2 Procedure........................................................................................................................................................ 36 C.3 Calculation of the variation of the circumferential residual stress located deep under

the tread .......................................................................................................................................................... 37

Annex D (normative) Product qualification .................................................................................................... 41 D.1 Introduction ................................................................................................................................................... 41 D.2 General ............................................................................................................................................................. 41 D.3 Requirements ................................................................................................................................................ 42 D.4 Qualification procedure ............................................................................................................................. 43 D.5 Qualification validity .................................................................................................................................. 45 D.6 Qualification file ........................................................................................................................................... 46

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Annex E (normative) Product delivery conditions ........................................................................................ 47 E.1 Introduction.................................................................................................................................................... 47 E.2 General ............................................................................................................................................................. 47 E.3 Delivery condition ........................................................................................................................................ 48 E.4 Controls on each wheel ............................................................................................................................... 48 E.5 Batch control .................................................................................................................................................. 48 E.6 Quality plan ..................................................................................................................................................... 50 E.7 Allowable rectification ............................................................................................................................... 51 E.8 Repeat testing ................................................................................................................................................ 51

Annex F (normative) Control of the hydrogen content in the steel for solid wheels at the melting stage .................................................................................................................................................. 52

F.1 General ............................................................................................................................................................. 52 F.2 Sampling .......................................................................................................................................................... 52 F.3 Analysis methods .......................................................................................................................................... 52 F.4 Precautions ..................................................................................................................................................... 52

Annex G (informative) Common applications of the steel grades ............................................................ 53

Annex ZA (informative) Relationship between this European Standard and the essential requirements of Directive 2008/57/EC aimed to be covered ...................................................... 54

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European foreword

This document (prEN 13262:2017) has been prepared by Technical Committee CEN/TC 256 “Railway applications”, the secretariat of which is held by DIN.

This document is currently submitted to the CEN Enquiry.

This document will supersede EN 13262:2004+A2:2011.

This document has been prepared under a standardization request given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive 2008/57/EC.

For relationship with EU Directive 2008/57/EC, see informative Annex ZA, which is an integral part of this document.

For a description of the technical changes in this new edition, see the introduction.

Informative annexes in this standard give additional information that is not mandatory but intended to assist the understanding or use of the document.

NOTE Informative annexes may contain optional requirements. For instance a test method that is optional, or expressed as an example, may contain requirements but there is no need to comply with these requirements to claim compliance with the document.

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Introduction

Since the first edition of this standard in 2004, the use of this standard shows need for clarification and improvement.

The most important modifications arise from difficulties encountered with product testing.

Some parameters were not sufficiently precise and could be incorrectly interpreted (e.g. the position of test pieces, the condition of use, measurement and interpretation of internal stresses using ultrasonic methods).

Another point was the introduction of a new material, ERS8, which can offer improved rolling contact fatigue (RCF) resistance.

As a consequence of possible demands for other materials, a further amendment was the introduction of an assessment process for the acceptance of new materials.

The three standards about wheelset, wheel and axle product requirement have been harmonised.

The annexes about product qualification and about product delivery conditions those were previously Informative have been amended according to the return of experience and have become normative.

Moreover, the TSIs “Fret Wagon” and “Loc & Pas” require that a verification procedure of the production exist.

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1 Scope

This European Standard specifies the characteristics of railway wheels for all track gauges.

This standard can also apply to light rail and tramway applications.

Five steel grades, ER6, ER7, ER8, ERS8 and ER9 are defined in this standard.

NOTE ERS8 has been integrated in this standard as an optimization of steel grades ER8 and ER9 in the context of RCF, and by taking into account European service experience e.g. BS 5892-3 in the UK.

Certain characteristics are defined according to a category 1 or a category 2. Category 1 is generally chosen when the operation train speed is higher than 200 km/h. Vehicles running at speeds lower than or equal to 200 km/h generally use wheels of category 2.

These categories can sometimes be subdivided, depending upon the characteristics.

This standard is applicable to solid forged and rolled wheels which are made from vacuum degassed steel and have a chilled rim. They are to have already been used in commercial conditions on a European network in a significant quantity, or to have satisfied a technical approval procedure according to EN 13979-1 for their design.

Annex A describes the assessment process for acceptance of new materials not cited in this standard.

The standard defines the wheel product requirements; the technical approval procedure is not within the scope of this standard.

NOTE Rim-chilled describes heat treatment of the rim, the aim of which is to harden the rim and to create compressive residual stresses in the rim.

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

EN 10020, Definition and classification of grades of steel

EN 13979-1:2003+A2:2011, Railway applications—Wheelsets and bogies—Monobloc wheels—Technical approval procedure—Part 1: Forged and rolled wheels

EN ISO 148-1, Metallic materials — Charpy impact test — Part 1: Test method (ISO 148-1)

EN ISO 1101, Geometrical product specifications (GPS) —Geometrical tolerancing—Tolerances of form, orientation, location and run-out (ISO 1101)

EN ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method (ISO 6506-1:2005)

EN ISO 6892 1, Metallic materials— Tensile testing— Part 1: Method of test at room temperature (ISO 6892-1)

EN ISO 12737, Metallic materials—Determination of plane-strain fracture toughness (ISO 12737)

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EN ISO 14284:2002, Steel and iron — Sampling and preparation of samples for the determination of chemical composition (ISO 14284:1996)

ISO 4967, Steel — Determination of content of non-metallic inclusions — Micrographic — method using standard diagrams

ISO 5948:1994, Railway rolling stock material — Ultrasonic acceptance testing

ISO 6933:1986, Railway rolling stock material — Magnetic particle acceptance testing

ISO/TR 97691), Steel and iron — Review of available methods of analysis

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

3.1 Technical specification document describing specific parameter and/or product requirements as an addition to the requirements of this standard

3.2 batch a batch is composed of wheels supposed to have the same characteristics

Note 1 to entry: A batch consists of wheels of the same design forged with raw material of a single heat in an identical hot forming process and heat treated in an identical procedure. If the raw material is produced in several heats with the expected chemical composition, the wheels made thereof can be combined to a batch. In this case, it needs to be proven within the frame of the product qualification that the wheels made of the various heats comply with the requirements of the product qualification.

4 Product definition

4.1 Chemical composition

4.1.1 Values to be achieved

The maximum percentages of the various specified elements are given in Table 1.

1) See also CR 10261:1995

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Table 1 — Maximum percentages of the various specified elements

Maximum content in %a

Steel grade C Si Mn P b S b, c Cr Cu Mo Ni V

Cr + Mo +

Ni

ER6 0,48 0,40 0,75 0,020 0,015 0,30 0,30 0,08 0,30 0,06 0,50

ER7 0,52 0,40 0,80 0,020 0,015 0,30 0,30 0,08 0,30 0,06 0,50

ER8 0,56 0,40 0,80 0,020 0,015 0,30 0,30 0,08 0,30 0,06 0,50

ERS8 0,57 1,10 1,10 0,020 0,015 0,30 0,30 0,08 0,30 0,06 0,60

ER9 0,60 0,40 0,80 0,020 0,015 0,30 0,30 0,08 0,30 0,06 0,50

a For special applications, variations within the maximum limit of these values may be agreed in the technical specification.

b A maximum content of 0,025 % may be agreed in the technical specification for specific application.

c A minimum sulphur content may be agreed in the technical specification according to the steelmaking process in order to safeguard against hydrogen cracking.

4.1.2 Location of the sample

The sample for determining the chemical composition shall be taken on the rolling circle 15 mm below the tread at its nominal diameter.

4.1.3 Chemical analysis

This chemical composition analysis shall be performed according to the methods and requirements described in ISO/TR 9769 or equivalent.

ASTM E415-14 and ASTM E1019-11 can be adopted.

4.2 Mechanical characteristics

4.2.1 Tensile test characteristics

4.2.1.1 Values to be achieved

Rim and web characteristics are given in Table 2.

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Table 2 — Rim and web characteristics of the wheels

Steel grade

Rim Web

ReH

(N/mm2)a

Rm

(N/mm2)

A5

%

Rm reduction

(N/mm2)b

A5

%

ER6 ≥ 500 780/900 ≥ 15 ≥ 100 ≥ 16

ER7 ≥ 520 820/940 ≥ 14 ≥ 110 ≥ 16

ER8 ≥ 540 860/980 ≥ 13 ≥ 120 ≥ 16

ERS8 ≥ 580 900/1020 ≥ 13 ≥ 110 ≥ 14

ER9 ≥ 580 900/1050 ≥ 12 ≥ 130 ≥ 14

a If no distinctive yield strength is present, the proof stress Rp0,2 shall be determined.

b Reduction of tensile strength as compared to tensile strength of the rim on the same wheel.

If there are no other requirements in the technical specification for material ER7, ER8, ERS8 and ER9, minimum yield strength of 355 N/mm2 in the web shall be required. For ER6, minimum yield strength of 310 N/mm2 in the web shall be required.

4.2.1.2 Location of test pieces

The test pieces shall be taken from the rim and the web of the wheel. Their positions are indicated in Figure 1.

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Dimensions in millimetres

Key

1 tensile test piece in the rim (centre at 15 mm below the tread with reference to the nominal diameter)

2 tensile test piece in the web 3 impact test piece 4 nominal diameter 5 notch

Figure 1 — Location of test pieces

4.2.1.3 Test method

The test shall be carried out in accordance with EN ISO 6892-1, method B. The test piece nominal diameter shall be at least 10 mm in the parallel length and the gauge length shall be 5 times the diameter. If the test piece cannot be taken from the web, a smaller diameter shall be agreed in the technical specification.

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4.2.2 Hardness characteristics in the rim

4.2.2.1 Values to be achieved

The minimum Brinell hardness values given in Table 3 are applicable up to a maximum wear depth of 35 mm under the tread. If the wear depth is greater than 35 mm, the values shall be defined in the technical specification.

In the rim-web transition (point A in Figure 2), hardness values should be at least 10 points less than the wear limit values.

Table 3 — Values to be achieved for hardness characteristics in the rim

Minimum Brinell hardness value

Steel grade Category 1 Category 2

ER6 — 225

ER7 245 235

ER8 245 245

ERS8 250 250

ER9 - 255

4.2.2.2 Location of readings

Four readings are carried out on a radial section of the rim as shown in Figure 2.

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Dimensions in millimetres

Key 1 profile at either the limit of wear or the last achievable turning diameter (according to the technical

specification) 2 nominal diameter 3 internal diameter (outer)

Figure 2 — Readings taken on a radial section of the rim

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4.2.2.3 Test method

The test shall be performed in accordance with EN ISO 6506-1. The ball diameter is 5 mm.

4.2.3 Impact test characteristics

4.2.3.1 Values to be achieved

Values to be achieved for impact test characteristics are shown in Table 4. For each temperature, they represent the average value and the minimum value for the three test pieces defined in 4.2.3.2. At +20 °C, U-notch specimens shall be used. At -20 °C, V-notch specimens shall be used.

Table 4 — Values to be achieved for impact test characteristics

Steel grade

KU at + 20 °C J

KV at - 20 °C J

Average values Minimum values Average values Minimum values

ER6 ≥ 17 ≥ 12 ≥ 12 ≥ 8

ER7 ≥ 17 ≥ 12 ≥ 10 ≥ 7

ER8 ≥ 17 ≥ 12 ≥ 10 ≥ 5

ERS8 ≥ 15 ≥ 11 ≥ 9 ≥ 5

ER9 ≥ 13 ≥ 9 ≥ 8 ≥ 5

4.2.3.2 Location of the test pieces

The positions of the three test pieces are indicated in Figure 1. The bottom notch axis shall be parallel to the A-A axis of Figure 1.

4.2.3.3 Test method

The test shall be performed in accordance with EN ISO 148-1.

4.2.4 Fatigue characteristics

4.2.4.1 Values to be achieved

Independent of the steel grade, the web shall withstand the stress range Δσ 99,7 % given by Table 5 during 107 cycles without any crack initiation, with a probability of 99,7 %.

Table 5 — Values to be achieved for fatigue characteristics of the web

Permissible fatigue stresses taken according to the technical approval of

the wheel (EN 13979-1)

Δσ

N/mm2

Values to be achieved for fatigue

characteristics

Δσ 99,7 %

N/mm2

360 450

290 315

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NOTE The aim of these characteristics is to guarantee that product characteristics are higher than those used for the definition of permissible stresses for the fatigue design of the web.

As there are many approximations in a fatigue calculation, it is not realistic to distinguish between the five steel grades. For ER6, if a lower value is expected it shall be specified and justified in the technical specification.

4.2.4.2 Test pieces for fatigue test

Test pieces shall consist of wheels as delivered. Their surface appearances are those defined in 4.6.

4.2.4.3 Test method

The test method shall allow bending stresses to be created in a web section.

The tests to demonstrate the fatigue properties shall be performed in such a manner that statistical evaluation to assess the results can be applied.

The tests are monitored by measuring the radial stresses that exist in the crack initiation area.

Examples of the method are given in Annex B.

4.2.5 Toughness characteristic of the rim

4.2.5.1 General

This characteristic need only be verified on tread braked wheels (service brake or parking brake), for category 1 or category 2.

4.2.5.2 Values to be achieved

For wheels of steel grade ER6, the average value obtained from six test pieces shall be greater than or equal to 100 N/mm2 √m, and no single value shall be less than 80 N/mm2 √m.

For wheels of steel grade ER7, the average value obtained from six test pieces shall be greater than or equal to 80 N/mm2 √m, and no single value shall be less than 70 N/mm2 √m.

For wheels of other steel grades, the values to be achieved shall be agreed in the technical specification.

4.2.5.3 Location of test pieces

Six test pieces shall be taken from the rim as indicated in Figure 3.

The test pieces shall be evenly distributed around the rim.

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Dimensions in millimetres

Key

1 nominal diameter

Figure 3 — Test pieces taken from the rim

4.2.5.4 Test method

The test shall be performed according to EN ISO 12737.

The particular conditions which shall be used are as follows:

— compact tensile test pieces: 30 mm thick (CT 30), with chevron notch with aperture angle of 90°;

— temperature during the test to be between +15 °C and +25 °C;

— measurement of the crack displacement of the test piece;

— rate of increase of stress intensity ΔK/σ should be within the range from 0.55 N/mm2 √m/s to 1 N/mm2 √m/s.

The value of the toughness to be considered is the value KQ which is calculated from the value of the load FQ from the load-displacement record.

For ER6 steel grade, when Fmax/Fq ≥ 1.4, Fmax data can be used to determine the KQ.

NOTE The explanation of this possibility is given in ERRI B169 DT 251.

4.3 Heat treatment homogeneity

4.3.1 Values to be achieved

For category 1 wheels, the variation in hardness values that are measured on the rim of the test wheel shall be no greater than 30 HB.

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NOTE The absolute values are not to be correlated with hardness value measured in the rim in 4.2.2 or with tensile tests results in the rim in 4.2.1.

4.3.2 Test pieces

The hardness measurement shall be undertaken at three points situated at 120 ° on the outside surface of the rim. The impressions shall be made on the same diameter in the area located as defined in Figure 4.

Dimensions in millimetres

Key

1 nominal diameter of the rolling circle 2 area for measurement of Brinell hardness

Figure 4 — Area for impressions

4.3.3 Test method

The test shall be performed according to EN ISO 6506-1. The ball diameter is 10 mm.

4.4 Material cleanliness

4.4.1 Micrographic cleanliness

4.4.1.1 Level to be achieved

It shall be measured by micrographic examination as defined in 4.4.1.2. The values to be achieved are given in Table 6.

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Table 6 — Level to be achieved for micrographic examination

Type of inclusions Category 1 Category 2

Thick series (maximum)

Thin series (maximum)

Thick series (maximum)

Thin series (maximum)

A (Sulfur) 1,5 1,5 1,5 2

Dsulf 1,5 2

B (Aluminate) 1 1,5 1,5 2

C (Silicate) 1 1,5 1,5 2

D (Globular oxide) 1 1,5 1,5 2

B + C + D 2 3 3 4

DS 1,5 2

4.4.1.2 Location of the micrographic sample

The examination field is situated in the shaded area of Figure 5.

Its centre "F" is situated 15 mm below the tread.

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Dimensions in millimetres

Key

1 nominal rolling circle

Figure 5 — Location of the micrographic sample

4.4.1.3 Test method

Determination of the level of cleanliness shall be made in accordance with the requirements of ISO 4967, method A.

4.4.2 Internal integrity

4.4.2.1 General

Internal integrity shall be defined from ultrasonic examination. Standard defects are flat-bottom holes with different diameters.

4.4.2.2 Level to be achieved

4.4.2.2.1 Rim

The rims shall have no internal defects which give echo magnitudes higher than or equal to those obtained for a standard defect situated at the same depth. The diameter of this standard defect is given in Table 7.

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Table 7 — Diameter of standard defect

Category 1

mm

Category 2

mm

Diameter of the standard defect 1 2a

a The value 3 mm can be adopted only for wheels up to 120 km/h, and this shall be stated in the technical specification.

There shall be no attenuation of the back echo greater than or equal to 4 dB during axial examination.

4.4.2.2.2 Web

The web shall not have

— more than 10 echoes with magnitudes greater than or equal to those obtained for standard defects of ø 3 mm,

— echoes with magnitudes greater than or equal to those obtained for standard defects of ø 5 mm.

The distance between two acceptable defects shall be at least 50 mm.

4.4.2.2.3 Hub

The hub shall not have

— more than 3 echoes with magnitudes greater than or equal to those obtained for standard defects of ø 3 mm,

— echoes with magnitudes greater than or equal to those obtained for standard defects of ø 5 mm.

The distance between two acceptable defects shall be at least 50 mm.

For one circumferential examination, no attenuation of the back echo equal to or greater than 6 dB is permitted.

4.4.2.3 Test piece

Examination shall be made of the complete wheel, after heat treatment, either before machining or in the finish machined condition, before corrosion protection is applied.

4.4.2.4 Methods of examination

4.4.2.4.1 General

Testing shall be carried out by qualified personnel.

NOTE EN ISO 9712 is a mean of achieving this requirement.

The general conditions for ultrasonic examination are given by ISO 5948 in accordance with the following special conditions.

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4.4.2.4.2 Rim

The rim examination shall be made according to the D1 and D2 methods of ISO 5948:1994, Table 1.

Defect estimation shall be made by comparison to artificial defects in the standard rim described by ISO 5948:1994, Figures 1 and 2.

4.4.2.4.3 Web

The type of curvature (convex/concave) of webs shall be taken into account when setting the sensitivity of the test procedure.

The artificial reference defects shall be created on both the inner and outer surfaces of the web.

The web examination shall be made from its two faces. The direction of the examination is perpendicular to the surface.

Defect estimation shall be made by comparison to artificial defects in a standard web.

The web is defined as the part of the wheel between the two diameters where m and n are defined in Figure 7.

The thickness e of the web is defined as:

𝑒𝑒 =𝑚𝑚 + 𝑛𝑛

2

The location of the artificial defects is given as a function of e. They shall be at least 100 mm apart in a circumferential orientation.

— e ≤ 10 mm:

— one 3 mm diameter flat bottom hole located 5 mm below the inner surface of the web,

— one 5 mm diameter flat bottom hole located 5 mm below the inner surface of the web;

— 10 mm < e ≤ 20 mm:

— two 3 mm diameter flat bottom holes located 5 mm and (e - 5) mm below the inner surface of the web,

— two 5 mm diameter flat bottom holes located 5 mm and (e - 5) mm below the inner surface of the web;

— e > 20 mm:

— three 3 mm diameter flat bottom holes located 5 mm, �𝑒𝑒2� mm and (e - 5) mm below the inner

surface of the web,

— three 5 mm diameter flat bottom holes located 5 mm, �𝑒𝑒2� mm and (e - 5) mm below the inner

surface of the web.

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4.4.2.4.4 Hub

The hub examination shall to be made from its two faces. The direction of the examination shall be perpendicular to the surface.

Defect estimation shall be made by comparison to artificial defects in the standard hub described by Figure 6.

Dimensions in millimetres

NOTE Calibration references are

— three 3 mm diameter holes located at different depths,

— three 5 mm diameter holes located at different depths,

spaced as shown in the figure above.

Figure 6 — Standard hub for ultrasonic examination

4.5 Residual stresses

4.5.1 General

Wheel heat treatment shall induce a compressive circumferential residual stress field inside the rim.

4.5.2 Values to be achieved

The circumferential residual stresses σcrs at the surface of the tread of the finished wheel shall be in a compressive state with σcrs ≤ -80 N/mm2. If the magnitude of the circumferential residual stresses at the surface of the tread of the finished wheel is lower than -200 N/mm2, it shall be proved that the level of radial residual stresses in the web is acceptable regarding fatigue behaviour.

NOTE The proof can be based on return of experience, fatigue test of the web, etc.

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The circumferential stresses shall be compressive to a depth of 35 mm. If the wear depth is greater than 35 mm, the value of the depth where the circumferential stresses are no longer compressive shall be defined in the technical specification.

4.5.3 Test piece

The test piece shall be the complete wheel after heat treatment and final machining.

4.5.4 Measurement methods

Measurement methods should estimate the variation of circumferential stresses located deep under the tread. This method shall be defined in the technical specification.

Annex C gives a method for this measurement.

4.6 Surface characteristics

4.6.1 Surface appearance

4.6.1.1 General

Machined webs are recommended for all wheel applications. Where unmachined webs are used, (e.g. for double corrugated wheels), then a magnetic particle inspection shall be undertaken according to 4.6.3.

The parts that remain "as forged" and/or "as rolled" shall be mechanically cleaned (e.g. shot-blasted) to remove any irregularities arising from the previous forging and heat treatment process and smoothly blended into the machined areas.

4.6.1.2 Characteristics to be achieved

According to their use, wheels may be fully or part machined. Their surface shall not show any marks other than those at the positions stipulated in this standard.

The surface roughness (Ra) of areas of "finished" or "ready for assembly" wheels are given in Table 8.

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Table 8 — Surface roughness (Ra) of wheels in the state of delivery

Area of the wheel State of deliverya Roughness Ra

μm

Category 1 Category 2

Bore Finished ≤ 12,5

Ready for assemblyb 0,8 to 3,2

Web and hub Finishedc ≤ 3,2 ≤ 6,3

(12,5 may be used if the proof of achieving

EN 13979-1 fatigue limit is given)

Rim tread Finished ≤ 6,3 ≤ 12,5d

Rim faces Finished ≤ 6,3 ≤ 12,5d

a See E.2.

b If the wheel has to be fitted on a hollow axle, other values may be required in the technical specification for the purpose of the in-service ultrasonic inspection.

c If defined in the technical specification, this area of the wheel may remain unmachined, provided the tolerances indicated in this table are achieved.

d ≤ 6,3 if required for a standard defect of 2 mm (see 4.4.2).

4.6.1.3 Inspection and measurement method

The overall condition of the wheel surface shall be checked by visual inspection.

The roughness of the wheel surfaces (Ra) in the state of delivery indicated in Table 8 shall be checked by comparison with the roughness specimen or measured with a profile meter on the plane surface.

4.6.2 Surface condition of the oil injection hole

The oil injection hole for wheel and groove shall be free from contamination and other obstruction. They shall be protected from contamination and damage during transportation and storage when the final machining of the wheel is completed.

4.6.3 Surface integrity

4.6.3.1 General

The surface integrity shall be determined by a magnetic particle test or if included in the technical specification, alternative methodologies may be adopted for delivery (see Table E.1).

4.6.3.2 Level to be achieved

The maximum trace length of permissible surface breaking defects are as follows, unless otherwise defined in the technical specification:

— 2 mm on machined faces;

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— 6 mm on black faces, either forged or rolled.

4.6.3.3 Test piece

Examination shall be made on the complete wheel after heat treatment, in the finished or part finished machined condition before corrosion protection is applied.

4.6.3.4 Methods of inspection

The general requirements for the magnetic particle test are defined in ISO 6933, except that

— the level of the surface magnetic induction shall be greater than or equal to 4 mT,

— the level of the lighting energy of ultra-violet light shall be greater than or equal to15 W/m2.

The magnetisation method to be used is indicated in ISO 6933:1986, Figure C.

The apparatus used shall scan the entire wheel surface and be able to detect the defects whatever their orientation.

Testing shall be carried out by qualified personnel.

NOTE EN ISO 9712 is a means of achieving this requirement.

After undergoing magnetic particle testing the solid wheels shall be demagnetised. The residual magnetism shall be less than 4 A/cm.

4.7 Geometric tolerances

4.7.1 General

The geometry and dimensions of wheels shall be defined by a drawing included in the technical specification.

The geometric tolerances shall comply with those in Table 9. The meaning of the symbols is defined in Figure 7.

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Key

1 Dimension defined by the drawing (position of the rolling circle)

Figure 7 — Symbols

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Table 9 — Geometric tolerances

Tolerances

Designation Symbols (see Figure 7) Values

Cat. 1

mm

Values

Cat. 2

mm

Dimensional Geometricala Unmachined Machined

Rim

External diameter a — 0/+4b — 0/+4b

Internal diameter (outer)

b1 — 0/-2 — 0/-4

Internal diameter (inner)

b2 — 0/-2 0/-6 0/-4

Width d — ±1 — ±1

Tread profilec — v ≤ 0,5 — ≤ 0,5

Circularity of the tread — s ≤ 0,1 — ≤ 0,2

Total run out of the bearing in axial direction

— t ≤ 0,2 — ≤ 0,3

Total run out of the rim in radial direction — j ≤ 0,2 — ≤ 0,2

External diameter of the wear groove W — 0/+2 — 0/+2

Hub

External diameter (outer)

f1 — 0/+2 0/+10 0/+5

External diameter (inner)

f2 — 0/+2 0/+10 0/+5

Internal diameter of the bore:

– “finished”d

g1 — 0/-2 — 0/-2

– “finished ready” for assemblyd

g2 — In accordance with the drawing or a standard to guarantee the interference fit

Cylindricity of internal diameter of the bore:

– “finished”d

– “finished ready for assembly”d

— x1

x2

≤ 0,1

≤ 0,02e —

≤ 0,2

≤ 0,02e

Length h — 0/+2b — 0/+2b

Hub to rim overhang r — 0/+2b — 0/+2b

Total run out of the diameter of the bore:

– “finished”d —

q1

q2

≤ 0,2

≤ 0,1 —

≤ 0,2

≤ 0,1

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– “finished ready for assembly”d

Web

Shapef — k ≤ 4 ≤ 8 ≤ 8

Thickness at the connection with the rim m — +2/0 +8/0 +5/0

Thickness at the connection with the hub n — +2/0 +10/0 +5/0

a See ISO 1101.

b For tractive stock other values may be necessary depending on the wheelset assembly process.

c From the top of the flange as far as the external chamfer.

d See E.3 for terms related to bore of the hub.

e Any slight taper within the permitted tolerance shall be such that the “larger” diameter is at the axle entry end of the bore on assembly of the wheel on the axle.

f The configuration of the wheel web should be considered at the connection with the rim and the hub.

4.7.2 Wear groove

Details of the wear groove diameter shall be defined in the technical specification, when required. Tolerances of the groove diameter shall be in accordance with Table 9.

Geometry of the wear groove shall be as defined in Figure 8.

Dimensions in millimetres

Tread side

Hub side

Figure 8 – Details of the wear groove

An alternative type of groove may be used for vehicle not submitted to the Directive 2008/57/EC but shall not have any sharp notch.

The application of the wear groove as a function of the vehicle submitted to the Directive 2008/57/EC is given in Table 10.

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Table 10 — Application of the wear groove on the wheels of vehicles submitted to the Directive 2008/57/EC

Vehicle type Groove on external face of the rim

Coaches Yes

Wagons Yes

Locomotives, other vehicles

Depending on the monitoring systema used by the undertaking

a Specific measurements of the wheel diameter.

4.8 Static imbalance

The maximum static imbalance of a finished wheel in the delivery condition is defined in Table 11.

The means and methods of measurement shall be defined in the technical specification.

Table 11 — Maximum static imbalance of the finished wheels in the delivery or ready for assembly state

For vehicles running at speed v

km/h

Static imbalance

g⋅m

Symbol

v ≤ 120 ≤ 125 E3

120 < v ≤ 200 ≤ 75 E2

200 < v ≤ 250 ≤ 50 E1

v > 250 ≤ 25 E0

4.9 Protection against corrosion

Protection shall be provided

— on all fully machined surfaces, with the exception of the surface of the rims,

— on the unmachined web and unmachined hub.

4.10 Manufacturer's marking

For purpose of traceability, each wheel shall be identified, as a minimum, with the following marks:

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— manufacturer's mark;

— cast number;

— steel grade;

— month and two last figures of the year of production;

— position of residual imbalance and its symbol (see 4.8);

— serial number after heat treatment.

These may be applied according Figure 9 or as defined in the technical specification. These marks shall be stamped, except for imbalance marks which may be made by other means. Stamps with sharp edges are not allowed.

Figure 9 — Manufacturer’s marking possible places

5 The manufacturer’s mark identifies the unique reference for quality and characteristics of the component. The manufacturer’s mark shall be put at the final manufacturing step prior to delivery. Product qualification

The product qualification shall follow Annex D.

6 Product delivery conditions

The product delivery conditions shall follow Annex E.

7 Advices to choose the steel grade

The informative Annex G gives advices to choose the steel grade.

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Annex A (normative)

Assessment process for acceptance of new materials

A.1 General

To enable the improvement of wheel service performance, this annex defines the steps that shall be followed in order to use a new steel grade and eventually integrate it into this Standard.

This annex is applicable to steel grades which are comparable to ER7 – ER9 (unalloyed carbon steel according to EN 10020 with C max up to 0,70 %) and having mechanical properties of the same range.

The design of the wheel from the new steel grade shall be demonstrated based on EN 13979-1.

The range of application for a new steel grade has to be confirmed by service experience (see A.3).

A.2 First step: Characterization of a new steel grade

A characterization report of the new steel grade shall be provided; this report shall define as a minimum all the material characteristics contained in clause 4 of this standard in terms of maximum or minimum ranges (including the results of full scale fatigue tests) and a recommendation for the application.

If this steel grade is to be considered for a design requiring different (higher or lower) permissible fatigue stress ranges than those defined in clause 4, then the fatigue limit shall be justified by a staircase method or equivalent, estimating the fatigue limit with a probability of 99,7 % (Δσ 99,7 %).

NOTE The Bastenaire method according to NF A 03-405 can be used.

A.3 Second step: Service testing period

The new steel grade shall be tested in service to demonstrate service safety and to enable to quantify the improvements of the service performance. To determine the influence of the new steel grade the service test shall be made as a comparable test relating to an existing steel grade.

The first batch of wheels, made of the new steel grade, produced according to the characteristics defined in A.2, before being installed for service testing, shall undergo the product and manufacturing qualification process defined in Annex D including the full scale fatigue tests.

NOTE For the full scale fatigue test, the results used to define the technical specification can be applied.

For the in-service test, a technical specification shall define

— the duration of the testing,

— the number of test pieces,

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— the inspection and monitoring program.

The duration of the testing shall be at least sufficient to quantify the actual improvements of the service performance without compromising the service safety.

After the in-service test, a report shall be compiled of the service testing results. A recommendation of the range of application shall be stated.

A.4 Third step: Report

A final report shall be prepared to analyse and compare the results from the first and the second steps, and give recommendation about the suitability for acceptance as a new wheel material.

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Annex B (informative)

Examples of benches for fatigue tests

B.1 Test piece

The test piece is the wheel itself.

B.2 First test method

B.2.1 Test rig

The principle of the test rig is shown in Figure B.1:

— the wheel is fitted on a simulated axle which is fixed to a face plate;

— forces are applied to the rim by a hydraulic actuator;

— the wheel remains fixed.

B.2.2 Test monitoring

The actuator is controlled by monitoring forces that are calibrated against the radial stresses that are measured in the area where the crack initiates.

The maximum and minimum forces applied are symmetrical about a mean load of 0 N.

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Figure B.1 — Functional diagram

B.3 Second test method

B.3.1 Test rig

The operating principle of the test rig is shown in Figure B.2.

The rotational bending fatigue test rig is a resonance testing machine in which the test piece acts as a spring in the machine’s oscillating system. The vibrational response of the test piece is determined primarily by the parameters mass, stiffness (spring constants) and damping. The excitation of the oscillating system is induced by a vibration motor. The load on the test piece is controlled by changing the rotational speed of the driver motor. Load changes are induced on the rising branch of the resonance curve below the resonant frequency.

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The test rig comprises a clamping plate fixed to a anti-vibration concrete block.

The half-wheelset is mounted on the clamping plate.

An electric motor with an unbalanced mass is placed on the wheelset axle shaft.

Figure B.2 — Functional diagram

B.3.2 Test monitoring

The drive motor, which is mounted on the axle shaft and has an unbalanced mass attached to it, induces a rotational bending motion in the wheelset axle. The controller is adjusted so that the stress generated in the wheel web is that associated with the chosen load level. The test piece is then subjected to 107 stress cycles at this stress level.

B.4 Third test method

B.4.1 Test rig

The operating principle of the test rig is shown in Figure B.3.

The wheel rim is fixed to the test rig structure.

On the journal at the opposite side of the axle, a bearing is fitted and placed in a metal sledge which can be displaced radially inside a rotor (the displacement is called "S" in Figure B.3).

The rotational bending fatigue test rig is obtained by a rotating the displacement (S).

The displacement (S) is regulated in order to obtain the required strain in the area of the wheel that has to be verified.

The strain is measured through strain gauges.

The rotation is given by an electric motor that acts on the rotor.

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Key

1 sledge 2 sotor

Figure B.3 — Functional diagram

B.4.2 Test monitoring

The strain gauges applied on the sections of the wheel to be tested are constantly monitored in order to prove the constant amplitude loading throughout the test.

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Annex C (informative)

Strain gauge method for determining the variations of circumferential residual stresses located deep under the tread (destructive method)

C.1 Principle of the method

The method comprises cutting operations leading to the progressive relief of residual stresses present in the rim.

The change in the state of residual stresses resulting from each cutting operation is evaluated at the surface by measuring local deformation using strain gauges.

The change in state inside the rim is obtained by a linear extrapolation of the state evaluated at the surface.

The evaluation is performed for one radial cross section only because, from experience, it is known that the heat treatment induces effectively a uniform circular state of residual stress.

C.2 Procedure

C.2.1 Fitting of a rim cross section with strain gauges prior to wheel cutting (Figure C.1)

Strain gauges are glued following:

— the circumferential and axial directions;

— at point 1 of the tread located in the plane of symmetry of the web-rim connection;

— the circumferential and radial directions;

— at points 2E of the external side and 2I of the internal side of the rim;

— at points 3E (external) and 3I (internal) of the web-fillet.

C.2.2 Execution of cutting (Figure C.2)

Cutting operations are performed following a procedure that will not induce residual stresses (except on the small thickness of the cutting areas).

Three cutting operations shall be performed in the following order:

a) extraction of a rim section of length s equal to at least twice the rim width, cutting along two radial directions and a plane parallel to the axle and located at a minimum depth of t below strain gauges 3I and 3E (operation 1 – Figure C.2a);

b) cutting along a plane parallel to the axle, located at the start of the web-rim connection (operation 2 – Figure C.2b);

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c) cutting along a plane parallel to the axle crossing the rim (operation 3 – Figure C.2c). This cutting process will only be performed if the thickness of the rim is greater than 30 mm.

C.2.3 Operations to be performed during cutting

1) Measuring the strains of the gauges after cutting operation n°1.

2) Recording the exact profile of the radial cross-section on one of the ends of the rim section.

3) Gluing gauge 4 (Figure C.2b).

4) Measuring the strains of gauges 1 and 4 after cutting operation n°2.

Measuring the thicknesses h1 and h2 (Figure C.2b).

5) Gluing gauge 5 (Figure C.2c).

6) Measuring the strains of gauges 1 and 5 after cutting operation n°3.

Measuring the thicknesses h1 and h2 (Figure C.2c).

C.3 Calculation of the variation of the circumferential residual stress located deep under the tread

C.3.1 General

The variation of the circumferential stresses 𝜎𝜎𝑗𝑗𝑖𝑖 resulting from each cutting operation "i" at measurement point "j" is calculated using the following formula:

𝜎𝜎𝑗𝑗𝑖𝑖 = −𝐸𝐸

1 − 𝑣𝑣2 �𝑒𝑒cir𝑗𝑗

𝑖𝑖 + 𝑣𝑣𝑒𝑒⊥𝑗𝑗𝑖𝑖 �

where

E = 210 000 MPa;

v = 0, 28;

𝑒𝑒cir𝑗𝑗𝑖𝑖 = circumferential measured strain;

𝑒𝑒⊥𝑗𝑗𝑖𝑖 = axial (or radial) measured strain.

C.3.2 Calculation of the variation of the circumferential stress created by cutting operation n°1

Calculate stresses 𝜎𝜎11, 𝜎𝜎2E1 , 𝜎𝜎2I

1 , 𝜎𝜎3E1 , and 𝜎𝜎3I

1 .

Stress values at points 2 and 3 (Figure C.3a) are given by the following formulae:

𝜎𝜎21 =𝑎𝑎

𝑎𝑎 + 𝑏𝑏𝜎𝜎2E1 +

𝑏𝑏𝑎𝑎 + 𝑏𝑏

𝜎𝜎2I1

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𝜎𝜎31 =𝑐𝑐

𝑐𝑐 + 𝑑𝑑𝜎𝜎3E1 +

𝑑𝑑𝑐𝑐 + 𝑑𝑑

𝜎𝜎3I1

The radial variation of the stress is represented by the straight line passing through the ordinates corresponding to points 1 and 3 in the stress diagram in relation to the distance between point and tread.

The representation of the calculated stress (Figure C.3a) at point 2 shall be located at ± 20 N/mm2 from this straight line.

C.3.3 Calculation of the variation of the circumferential stress created by cutting operation n°2

Calculate stresses 𝜎𝜎12 and 𝜎𝜎42, then the stress at point A (Figure C.2b) using the following formula:

𝜎𝜎A2 =

−(2ℎ1 + ℎ2)𝑆𝑆1𝜎𝜎12 + ℎ2𝑆𝑆2𝜎𝜎42

𝑆𝑆1(ℎ1 + ℎ2)

The radial variation of the stress is represented by the straight line passing through the ordinates corresponding to points 1 and A in the stress diagram in relation to the distance between point and tread (Figure C.3b).

C.3.4 Calculation of the variation of the circumferential stress created by cutting operation n°3

Calculate stresses 𝜎𝜎13 and 𝜎𝜎53, then the stress at point A (Figure C.2c) using the following formula:

𝜎𝜎B3 = −

(2ℎ1 + ℎ2)ℎ1 + ℎ2

𝜎𝜎13 +(ℎ2)2

ℎ1(ℎ1 + ℎ2)𝜎𝜎53

The radial variation of the stress is represented by the straight line passing through the ordinates corresponding to points 1 and B in the stress diagram in relation to the distance between point and tread (Figure C.3c).

C.3.5 Final diagram representing the variation of the circumferential stress located deep under the tread

Determine stress values: 𝜎𝜎B1 and 𝜎𝜎B

2 using the Figure C.3a and Figure C.3b diagrams.

The value of the circumferential residual stress σ1 at point 1 is equal to the algebraic sum of the measured values of the stresses after each cutting process:

𝜎𝜎1 = 𝜎𝜎11 + 𝜎𝜎12 + 𝜎𝜎13

Similarly, the σB value at point B is equal to:

𝜎𝜎B = 𝜎𝜎B1 + 𝜎𝜎B

2 + 𝜎𝜎B3

The final diagram of the variation of the deep circumferential stress is represented by the straight line passing through the ordinates σ1 and σB corresponding to points 1 and B in the stress diagram in relation to the distance between point and tread (Figure C.3d).

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Figure C.1 — Fitting with strain gauges

Figure C.2.a Cutting operation n°1

Figure C.2.b Cutting operation no. 2

Figure C.2.c Cutting operation n°3

Figure C.2 — Cutting operation

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Figure C.3.a

Figure C.3.b

Figure C.3.c Figure C.3.d

Figure C.3 — Determination of variation of circumferential residual stress located deep under the tread

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Annex D (normative)

Product qualification

D.1 Introduction

This annex describes the minimum requirements for product and manufacturing process qualification.

Further requirements may be specified in the technical specification.

D.2 General

This clause specifies the requirements and procedures to be applied for product and manufacturing process qualification.

Qualification of a wheel is directly linked to the manufacturing process and a wheel can only be qualified if the manufacturing process meets the requirements specified in D.3.

These requirements and procedures apply only to wheels for which the design has already been approved

— either by previous use in European railway services,

— or by a recognized technical approval procedure2).

The qualification of a product is based on product groups. The product groups are defined by the combination of the following requirements:

1) geometry – shape of the web: straight web, light shaped web, deep shaped web, web with bores, special design (qualification for deep shaped web includes light shaped web and straight web);

2) category 1 or 2 (qualification for category 1 includes category 2);

3) material

d) ER6 – ER7 – ER8,

e) ERS8,

f) ER9,

g) new material;

2) See EN 13979-1.

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4) permissible fatigue stress range (see Table D.1) (qualification for 360 MPa includes 290 MPa).

The qualification process shall be applied if the wheel is not included in the product groups of qualified wheels of the manufacturer.

Any change in the manufacturing process

— raw material (steel),

— forging,

— heat treatment,

— final machining,

— site of production,

shall be documented and can require partial or complete requalification of the product, depending upon the changes made.

D.3 Requirements

D.3.1 Requirements to be met by the manufacturing process

D.3.1.1 General

Where manufacture of a wheel involves more than one manufacturer, the following requirements shall be met by all concerned.

D.3.1.2 Quality organization

The manufacturer shall operate a quality assurance system.

NOTE EN ISO 9001 is a mean of achieving this requirement.

D.3.1.3 Staff qualification

Staff trained in non-destructive testing shall be qualified.

NOTE EN ISO 9712 is a mean of achieving this requirement.

D.3.1.4 Equipment

The equipment used by the supplier for manufacture, control and monitoring shall allow the requirements of this standard to be met.

An automatic process shall be used for ultrasonic examination of the rim.

D.3.2 Requirements to be met by the product

The product shall meet the product requirements specified in clause 4.

Traceability of each wheel shall be established from the cast onwards.

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D.4 Qualification procedure

D.4.1 General

The qualification procedure for the product comprises four successive stages described below:

— provision of the documentation by the manufacturer;

— evaluation of the manufacturing equipment and manufacturing processes;

— laboratory tests;

— service experience of wheels.

After each stage, a report shall be produced.

After the third stage, temporary qualification is given in order to allow in-service experience of the wheels to be gained.

D.4.2 Documentation required

For the qualification a file shall be produced comprising

— a description of the wheels that are the subject of the qualification,

— a description of the manufacturing company stating

— company size (number of employees, defining the proportion between manufacturing, control and quality assurance),

— annual production of wheels,

— a list of all the means of production and control,

— data about the company organization, with the relevant organization charts,

— a description of the manufacturing processes with explanations of the different stages of manufacture,

— data about raw materials with the list of manufacturers,

— results of tests on the products that are the subject of the request,

— qualification reports if the product has been previously qualified.

If a file has already been provided by a manufacturer for the qualification of a different wheel, the file to be provided by this manufacturer for the qualification of a new wheel shall include only data specific to this new wheel or new to the company.

D.4.3 Evaluation of the manufacturing plant and of the manufacturing processes

This evaluation comprises

— an inspection of the manufacturing plants and examination of the manufacturing processes,

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— an inspection of the raw material manufacturing plant and examination of its manufacturing processes,

— auditing of the data provided by the manufacturer to confirm whether the requirements of D.3.1 have been fully met,

— auditing of the information provided in the documents referred to in D.4.2.

At the end of this stage, a report shall be produced. It shall identify all the manufacturing processes including those of the raw material which are essential for product quality for which qualification is requested. It shall give an assurance that the evaluation satisfies the requirements of D.3.1 for the qualification procedure to continue.

D.4.4 Laboratory tests

All characteristics defined in clause 4, except fatigue characteristics, shall be proven for two wheels taken from the industrial production process.

In order to ensure that the fatigue characteristics defined in 4.2.4.1 are achieved, it shall be verified on two other wheels using the test method described in 4.2.4.3, but without statistical evaluation, that for a radial stress level equal to that given in Table D.1 and due to an external symmetrical loading there is no fatigue crack initiation after 107 cycles. For ER6, if a lower value is expected it shall be specified and justified in the technical specification.

The fatigue characteristics need not to be verified when the maximum radial stresses, calculated with the method defined by EN 13979-1 are below 50 % of the permissible fatigue stress range according to EN 13979-1.

Table D.1 — Level of radial stress

Permissible fatigue stress range according to

EN 13979-1

Δσ

MPa

290 360

Value obtained from a fatigue test programme according to

Annex A or to clause 7.2.3 of

EN 13979-1

Radial stress symmetrical loading

amplitude for verification

MPa

±168 ±240 ± Δσ99,7 %/2 x 1,066

For better identification of the product to be qualified, there may be a need for further tests (metallographic, etc.) to be conducted at this stage, in addition to those mentioned in clause 4. The results of these tests have no influence on the final decision on qualification.

A report shall be produced at the end of this stage describing the test piece, the tests carried out and the results obtained. It shall specify whether or not the wheels tested are in compliance with the requirements.

If the outcome is satisfactory, a provisional qualification shall be issued.

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According to the process, the batch to be used for the delivery shall be defined.

D.4.5 Testing of wheels

D.4.5.1 Extended manufacturing inspection

After provisional qualification, the first batches of series production of the product to be qualified shall be subjected to extended inspection according to the "qualification" column of Table E.1. Each batch shall comprise wheels from the same melting charge and shall have been heat treated under the same conditions. Each batch shall comprise at least 24 wheels.

D.4.5.2 Operational testing

The first wheels supplied on the basis of a provisional qualification shall be specially monitored in service. For this purpose, a programme shall be defined in the technical specification. It shall comprise:

— definition of the number of wheels to be monitored;

— description of the intermediate and final inspections;

— time period for the testing.

D.4.5.3 Results of operational testing

The product shall be deemed as qualified at the earliest 2 years after the first wheel has entered service provided that the acceptance tests defined in the "qualification" column of Table E.1 have not resulted in any repeated problems. The number of wheels supplied according to the "qualification" column of Table E.1 is limited to 1 000 wheels or 10 batches.

A new report shall be produced. It shall contain as a minimum:

— the number of wheels and batches;

— the results of the operational testing;

— the number of wheels rejected during the tests and the reasons for the rejection.

D.5 Qualification validity

D.5.1 Condition of validity

The qualification shall specify the limits of validity in accordance with the product group (see D.2).

D.5.2 Modification and extension

The scope of the certification validity may be modified or extended if

— other products are to be considered,

— the main parameters have been modified (manufacturing processes, quality organization, etc.).

Any modifications or change in the scope of qualification shall be agreed and documented.

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D.5.3 Transference

In the case of a change in ownership, an existing qualification may, if requested, be transferred to another company if the relevant content and conditions prior to the qualification have not been modified.

D.5.4 Lapsed certification

The manufacturing equipment and processes described in D.4.3 shall be re-assessed in the following cases:

1) if, after 5 years, 300 wheels have not been supplied following the provisional qualification;

2) if, in a period of 2 years, no wheels have been supplied within the scope of the product that was the subject of the qualification.

The wheels of the first batch of the new production shall be supplied according to the "qualification" column of Table E.1.

D.5.5 Cancellation

If significant defects in the product are registered, the parts of the qualification procedure concerned shall be repeated.

If the manufacturer has not ensured that important conditions of the qualification were met, it may be cancelled.

D.6 Qualification file

A qualification file shall be prepared for each qualified product. It shall contain the following documents:

— the documents provided by manufacturer (see D.4.2);

— the assessment reports (see D.4.3);

— the laboratory test reports (see D.4.4);

— the utilization report (see D.4.5);

— the qualification reports (see D.5);

— definition of the characteristics of the batch.

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Annex E (normative)

Product delivery conditions

E.1 Introduction

This annex describes the minimum product delivery conditions.

Further requirements may be specified in the technical specification.

E.2 General

The technical specification shall define:

— the geometry and the dimensions of the wheel (drawings);

— the category of the wheel (1 or 2 – see clause 1);

— the minimum and maximum contents of the elements if necessary (see Table 1);

— the braking mode of the wheel, tread brake, disc brake type etc. (see 4.2.5);

— the diameter of standard defects for internal integrity of the rims of category 2 (see Table 7);

— the type of corrosion protection (see 4.9);

— the identification location (see 4.10);

— whether the nominal diameter of the rolling circle needs to be marked;

— the delivery condition (see E.3).

The technical specification shall identify the method of manufacturing quality supervision of the products

— either by batch control as described in E.5.1,

— or by an agreed quality plan, as indicated in E.6.

The technical specification shall also define:

— test piece diameter (see 4.2.1.3);

— measurement methods (see 4.5.4, 4.8, E.5.3);

— surface integrity inspection (see Table E.1, note f and E.5.4);

— permissible imbalance (see E.5).

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As a minimum, the manufacturers shall be identified and documented in the product delivery certificates of conformity for the following steps of the production process:

— steel making;

— forging;

— heat treatment;

— machining.

E.3 Delivery condition

The wheels shall be delivered in one of the following conditions:

— unmachined (as-forged or as-rolled condition) where the wheel has not been machined except for what the manufacturer has to do to make the wheel compatible with the requirements of this standard;

— rough-machined, (if requested) where the wheel has been machined and requires subsequent machining;

— semi-finished, where the wheel, except for the bore, is finish machined in some parts, but other parts require final machining;

— finished, where the wheel has undergone final machining (all parts apart from the bore);

— finished, ready for assembly, where all parts of the wheels including the bore are in the final machined state for assembly.

E.4 Controls on each wheel

Whether the fabrication quality supervision is made with controls by batch sampling (see E.5), or with a quality plan (see E.6), controls are required to ensure that the special characteristics, which are defined in clause 4, are obtained. These controls shall be made on each delivered wheel (see E.2), and are

— internal integrity of the rims (see 4.4.2),

— surface integrity (see 4.6.2 or E.5.4),

— imbalance (see 4.8),

— tread diameter, bore diameter, tread run out and rim profile (see 4.7).

E.5 Batch control

E.5.1 Controls

The nature and number of controls are defined in the "delivery" column of Table E.1; a batch comprises wheels from the same cast and heat treated under the same conditions.

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Table E.1 — Type and number of controls to be carried out

Characteristics to be verified Number of wheels per batch to control Subclause reference

Qualification (see D.4.5)

Delivery (see E.4)

Maximum size of the batch ≤ 100 ≤ 250 > 250 –

– Chemical composition 1 1 1 4.1

– Hydrogen content a a a b

– Tensile characteristics

in the rim 1 1 2 4.2.1

in the web 1 1 2 4.2.1

– Hardness on rim parts 1 1 2 4.2.2

– Hardness on rim (homogeneity) 100 % 100 % 100 % E.5.2

– Impact tests 1 1 2 4.2.3

– Toughnessc 1 1 1 4.2.5

– Heat treatment homogeneity 10 %d 1 2 4.3

– Inclusion cleanliness 1 1 2 4.4.1

– Internal integrity

Rim 100 % 100 % 100 % 4.4.2

hub 100 % - - 4.4.2

web 20 %e - - 4.4.2

– Residual stresses trends 1 1 2 f

– State of surface 100 % 100 % 100 % 4.6.1

– Surface integrity 100 % 100 %g 100 %g 4.6.3

– Geometry and dimensions 100%h 100%h 100 %h 4.7

– Static imbalance 100 % 100 % 100 % 4.8

a One analysis by cast. Sampling shall make it possible to ensure that the content measured is representative of the maximum hydrogen content of the cast.

b The hydrogen content is determined according to the methods described in Annex F (normative). It has to be ≤ 2 ppm for wheels of category 1 and ≤ 2,5 ppm for wheels of category 2.

c Only tread braked wheels. The results of the fracture toughness test of samples from a small batch of wheels can be assumed for additional batches delivered up to an overall total of 250 wheels in a twelve-month period, provided that the results of previous fracture toughness tests were within specification.

d Only category 1 wheels. e The rejection of one wheel in a batch will require verification of the whole batch. f Clause 5 for qualification and E.5.3 for delivery. g In accordance with the technical specification, visual inspection as defined in E.5.4 may replace magnetic particle inspection. h Tread diameter, bore diameter, tread run out, rim profile, conformity to permitted deviation from circularity on at least one wheel

from a production batch.

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E.5.2 Homogeneity of batches by measurement of the hardness of the rim

The measurement of the Brinell hardness (10 mm diameter ball) shall be checked on the rim of each wheel, after heat treatment.

The test will be undertaken in accordance with the requirements of EN ISO 6506-1 on the flat surface opposite to the flange. The impression shall be located as shown in Figure 4.

The extreme hardness values of the rims of wheels from the same batch shall not exceed 30 HB. Brinell hardness impressions may be left on the surface.

This test may be carried out before machining. On unmachined wheels the measurement area has to be prepared by local machining to remove the decarburized zone.

E.5.3 Orientation of residual stresses on rim chilled wheels

The existence of compressive stresses shall be verified by measuring the reduction in the distance between 2 marks, 100 mm apart, marked in the middle of the rim thickness on the opposite side to the flange after a radial cut has been made from the top of the flange to the bore halfway between the two marks.

After the internal stresses are relieved, the distance between the 2 marks shall reduce by a value ≥ 1 mm.

Criteria and method defined in 4.5.4 can also be used and shall be defined in the technical specification.

E.5.4 Visual examination

The visual examination shall be made under normal conditions of vision.

The acceptability criteria shall be established on the basis of the reference images to be defined in the technical specification.

E.6 Quality plan

E.6.1 General

In the case of quality control by a quality plan of the products to be delivered, it shall be defined in the technical specification.

NOTE Quality plan according to the definition in EN ISO 9001 or equivalent.

This quality plan shall refer to the quality manual of the manufacturer; it shall contain specific elements for the product.

E.6.2 Purpose

This plan shall be drawn up in the technical specification with the objective of:

— describing the processes and quality control in order to achieve the required quality of the product to be delivered. The reasons for their selection shall be given;

— the quality plan shall provide, at least, the same confidence as that from batch control.

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This quality plan shall define the controls that are made during the manufacturing process and those for product delivery. These controls may be collated in the control plan of the manufacturing process.

E.6.3 Application of the quality plan

Any modification to the quality plan shall be defined in the technical specification.

If a non-conformity is discovered on the products delivered, the applicable clauses of the quality plan shall be discussed and if the result is unsatisfactory the quality plan can be cancelled.

In this case, the controls and tests defined by the "control by sampling of batches" mode shall be applied in their entirety until a new agreement is reached.

E.7 Allowable rectification

With the exception of tread surfaces and bore, surface defects may be eliminated by fine-grained grinding with gradual transition within the dimensional, geometrical and finished surface tolerances.

All rectifications shall be in accordance with the conditions given in 4.6.3.

Elimination of residual imbalance is authorized by eccentric machining of the fillet between the web and the rim on the flange side. The thickness of metal removed shall not exceed 4 mm. The resultant surface shall be carefully blended into the adjacent material. If damping equipment is fitted in the area, the balancing area shall be agreed in the technical specification.

E.8 Repeat testing

If a mechanical test fails to meet the requirements, a technical analysis of the non-conformity shall be performed to substantiate repetition of test if admitted in the technical specification.

For example, when tensile strength test and impact test result failed to meet the required specification, they can be repeated twice in its entirety in accordance with Table 2 and Table 4, unless the batch is withdrawn. Repeat tests shall be carried out on test samples taken from two different wheels (if there are 250 or fewer wheels in the batch) or from two different wheels per 250 wheels (if there is more than 250 wheels in the batch). The batch shall be rejected if any individual test result from a repeat test fails to meet the relevant specified value. All test results shall be documented.

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Annex F (normative)

Control of the hydrogen content in the steel for solid wheels at the melting

stage

F.1 General

As no European Standard covers this subject, this annex specifies the requirements for this control.

F.2 Sampling

In order to meet the specified requirements, samples are taken from the molten bath using one of the following 4 methods:

— copper mould;

— silica dip tubes;

— quartz bubbling tube (translucent quartz is prohibited because of its hygroscopic ability);

— immersion probe method (carrier gas method with thermal conductivity detector).

F.3 Analysis methods

Two methods are accepted:

— vacuum extraction in a temperature range of 650 °C to 1050 °C;

— injecting a carrier gas (N2) at 650 °C ± 20 °C into the liquid steel. The resulting diffused gas containing hydrogen is recovered for re-circulation and analysis.

Other methods can be agreed in the technical specification if the same accuracy can be achieved.

F.4 Precautions

See EN ISO 14284:2002, 6.5.

The operators should be specifically trained for performing this analysis.

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Annex G (informative)

Common applications of the steel grades

The choice of steel grade for a specific application shall take into account service experience and the braking system used.

NOTE Service experience on the European network has demonstrated that ER7 steel grade suits the widest range of applications.

Table G.1 summarizes the more common applications.

Table G.1 — Common applications of the steel grades

Steel Grade Common application

ER6 ER6 is normally applied in low axleload situations

ER7 ER7 steel grade suits the widest range of applications

ER8 ER8 normally applied for higher duty applications

ERS8 ERS8 can be used for non 100 % tread braked vehicles and can offer improved rolling contact fatigue (RCF) resistance

ER9 A typical application for ER9 is high contact stress wheels e.g. “rolling road” and locomotives for non 100 % tread braked vehicles

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Annex ZA (informative)

Relationship between this European Standard and the essential

requirements of Directive 2008/57/EC aimed to be covered

This European Standard has been prepared under a Commission’s standardization request M/483 to provide one voluntary means of conforming to essential requirements of Directive 2008/57/EC on the interoperability of the rail system (recast).

Once this standard is cited in the Official Journal of the European Union under that Directive 2008/57/EC, compliance with the normative clauses of this standard given in Table ZA.1 for freight wagons, and Table ZA.2 for locomotive and passenger RST confers, within the limits of the scope of this standard, a presumption of conformity with the corresponding essential requirements of that Directive and associated EFTA regulations.

Table ZA.1 — Correspondence between this European Standard, the Commission Regulation n°321/2013 of 13 March 2013 (and its amendments 1236/2013 and 2015/924) concerning the

technical specification for interoperability relating to the subsystem ‘rolling stock – freight wagons’ of the rail system in the European Union and repealing Decision 2006/861/EC

(published in the Official Journal L 104, 12.4.2013, p.1) and Directive 2008/57/EC

Corresponding text, articles/§/annexes

of the Directive 2008/57/EC

Chapter/§/annexes of the Technical Specification for

Interoperability (TSI)

Clause/subclauses of this European

Standard

Comments

Annex III, Essential requirements

1. General requirements

1.1. Safety Clauses 1.1.1, 1.1.2, 1.1.3

1.2. Reliability and availability

1.5. Technical compatibility

2. Requirements specific to each subsystem

2.4. Rolling stock

2.4.2. Reliability and availability 2.4.3. Technical compatibility §3.

4. Characterisation of the subsystem

4.2. Functional and technical specifications of the subsystem

4.2.3. Gauging and track interaction

4.2.3.6. Running gear 4.2.3.6.3. Characteristics of wheels

5. Interoperability constituents

5.3. Interoperability constituent specifications 5.3.3. Wheel

6. Conformity assessment and EC verification

6.1. Interoperability constituent 6.1.2. Conformity assessment procedures 6.1.2.2. Wheel

The whole standard is applicable

The previous version of this EN is referred to in the Appendix C of the TSI and is therefore mandatory. This new version is equivalent.

The symbols of the geometric parameters of the wheelset are those used by the wheelset maintenance experts and are not those used in the TSI

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Table ZA.2 — Correspondence between this European Standard, the Commission regulation n°1302/2014 of 18 November 2014 concerning the technical specification for interoperability relating to the ‘rolling stock locomotives and passenger rolling stock’ of the rail system in the

European Union (published in the Official Journal L 356, 12.12.2014, p.228) and Directive 2008/57/EC

Corresponding text, articles/§/annexes of

the Directive 2008/57/EC

Chapter/§/annexes of the technical

specification for interoperability (TSI)

Clause/subclauses of this European

Standard

Comments

Annex III, Essential requirements

1. General requirements

1.1. Safety Clauses 1.1.1, 1.1.2, 1.1.3

1.2. Reliability and availability

1.5. Technical compatibility

2. Requirements specific to each subsystem

2.4. Rolling stock

2.4.2. Reliability and availability 2.4.3. Technical compatibility §3.

4. Characteristics of the Rolling stock subsystem

4.2. Functional and tech-nical specification of the sub-system

4.2.3. Track interaction and gauging

4.2.3.5 Running gear 4.2.3.5.2 Wheelsets §4.2.3.5.2.1 Mechanical and geometric characteristics of wheelsets §4.2.3.5.2.2 Mechanical and geometrical characteristics of wheels

5. Interoperability constituents

5.3. Interoperability constituent specification §5.3.4. Wheels

6. Assessment of conformity or suitability for use and ‘EC’ verification

6.1. Interoperability constituents

6.1.3. Particular assessment procedures for interoperability constituents §6.1.3.1. Wheels

The whole standard is applicable

The symbols of the geometric parameters of the wheelset are those used by the wheelset maintenance experts and are not those used in the TSI

WARNING 1 — Presumption of conformity stays valid only as long as a reference to this European Standard is maintained in the list published in the Official Journal of the European Union. Users of this standard should consult frequently this list

WARNING 2 — Other Union legislation may be applicable to the product(s) falling within the scope of this standard.

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Bibliography

[1] CR 10261:1995, Eciss Information Circular 11 - Iron And Steel - Review Of Available Methods Of Chemical Analysis

[2] EN ISO 9001, Quality management systems — Requirements (ISO 9001)

[3] EN ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel (ISO 9712)

[4] BS 5892-3, Railway rolling stock materials — Part 3: Specification for monobloc wheels for traction and trailing stock

[5] ERRI B169 DT 251 Tenacité à la rupture des roues ferroviaires; méthodes de détermination (Toughness characteristic of the railway wheels; determination methods)

[6] NF A 03-405, Metal Products — Fatigue Testing — Data Statistical Processing

[7] ASTM E415-14, Test Method for Analysis of Carbon and Low-Alloy Steel by Spark Atomic Emission Spectrometry

[8] ASTM E1019-11, Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by Various Combustion and Fusion Techniques