mast testing ppt
TRANSCRIPT
TRACTION MAST TESTING
INDEX
Sr
No.
Description Page No.
1. Types of Tests 03
2. Chemical Test 04-05
3. Mechanical Test 06-10
4. Ultrasonic Test 11-13
5. Retests 14-19
6. Galvanizing Tests 20-28
TYPES OF TEST
(1) CHEMICAL TEST (2) MECHANICAL TEST (a) Tensile Test (b) Impact Test (c) Temperature Test (3) ULTRASONIC TEST (4) RETESTS (5)GALVANAZATION TEST
(1)CHEMICAL TEST non-alloy quality steels
(1) CHEMICAL TEST for fine grain steels
(2) MECHANICAL TEST
(a) Test Temperature:-* Tensile tests shall be carried out in the temperature
range 10 °C to 35 °C. Impact tests shall be carried out at the temperatures specified for non-alloy steels and for fine grain steels.
(b)Tensile Test:- * The test is carried out at ambient temperature between 10 °C to 35 °C , unless otherwise
specified. test carried out under controlled condition shall be made at a temperature of 23 °C ± 5 °C .
(c) Impact tests :- The impact the following requirements shall apply:(I)The average value of a set of three test pieces shall
be equal to or greater than the specified value. One individual value may be below the specified value, provided that it is not less than 70 % of that value.
(II)If the conditions under (a) are not satisfied then an additional set of three test pieces may be taken, at the discretion of the manufacturer, from the same sample and tested. To consider the test unit as conforming after testing the second set, the following conditions shall all be satisfied simultaneously:
(II) (a) The average value of the six tests shall be equal to or greater than the minimum specified value.*
(b) Not more than two of the six individual values may
be lower than the minimum specified value;
(c) Not more than one of the six individual values may be
lower than 70% of the minimum specified value.
(III) If these conditions are not satisfied, the sample
product is rejected and retests.
(2) MECHANICAL TEST non-alloy quality steels
MECHANICAL TEST for fine grain steels
(3) ULTRASONIC TEST The method used is based on the reflection of
ultrasonic waves (generally longitudinally),the direction of which is approximately perpendicular
to the surface of the product . Procedure for testing :-* Ultrasonic testing shall be performed in
accordance with written procedure ,Where specified in this enquiry or order , the written procedure shall be submitted to the purchaser for approval prior for testing.
This written procedure shall be in form of :-
(a) a product specification or ; (b) a procedure written specially for the application;The procedure shall contain minimum requirement;(a) description of item to be examined;(b) reference document;(c) qualification and certification of examination personnel ;(d) stage of manufacture at which the examination is carried out ;(e) examination zone specified in terms of applicable quality classes;
(f) any special preparation of scanning surface , if applicable;
(g) couplant;(h) description of examination equipments;(i) recording level; (j) characterization of discontinuities;(k) calibration ;(l) recording level;(m) acceptance criteria;(n) examination report;
(4) RETESTS
General:- Where one or more tests given unsatisfactory
results the manufacturer may either withdraw the test unit require re-tests in accordance with following method:-
(a) Non- sequential tests :- Where the unsatisfactory results comes from
tests for which no average , but only individual values are
specified the following shall be carried out.
* The test unit is single piece. Two new tests of the same type as the one giving
unsatisfactory result shall be carried out . both new tests shall give satisfactory results . If not , product shall be
rejected .* The test unit is more then one piece the manufacturer
may at his discretion , retain in the test unit the sample product from which the unsatisfactory test result has
been obtained. (b) Sequential test :-The impact the following requirements shall apply:(I)The average value of a set of three test pieces shall be
equal to or greater than the specified value. One individual value may be below the specified value, provided that it is not less than 70 % of that value.
(II)If the conditions under (a) are not satisfied then an additional set of three test pieces may be taken, at the discretion of the manufacturer, from the same sample and tested. To consider the test unit as conforming after testing the second set, the following conditions shall all be satisfied simultaneously:
(II) (a)The average value of the six tests shall be equal to or greater than the minimum
specified value.* (b) Not more than two of the six individual
values may be lower than the minimum specified value;
(c)Not more than one of the six individual values may
be lower than 70% of the minimum specified value.
(III) If these conditions are not satisfied, the sample
product is rejected and retests.
Non sequential test
Non sequential test
GALVANAZATION TEST
(A) TYPE TESTS
(1) Visual Inspection
(2) Adhesion of coating
(3) Uniformity of coating
(4) Mass of zinc coating
(B) ACCEPTANCE TESTS (1) Visual Inspection (2) Adhesion of coating (3) Uniformity of coating (4) Mass of zinc coating
(C) ROUTINE TESTS (1) Visual Inspection
TEST METHODS
(1). VISUAL INSPECTION : - The material shall be inspected visually to
observe that it is smooth, reasonably bright, continuous and free from such imperfections a flux/ash/dross inclusions, bare patches, black spots, pimples, lumpiness runs, rust stains, bulky white deposits and blisters. The stains of flux, usually white in color, shall not be regarded as flux intrusions.
(2).ADHESION OF GALVANISED COATING :- Coating shall withstand the knife tests as prescribed
in IS : 2629-1966.when cut or pried into, such as with a stout knife applied with considerable pressure , in a manner tending to remove a portion of the coating , it shall only be possible to remove small particles of the coating ; and it shall not be possible to peel any portion of the coating so as to expose iron or steel underneath.
(3). UNIFORMITY OF GALVANISED COATING :- On small articles, which can be conveniently
handled the uniformity of the coating shall be determined by Preece Test in accordance with IS : 2633-1966 by dipping the whole article in the copper sulphate solution. For tubes, 100 mm long piece shall be cut from each end of the product, after discarding 300 mm length from the end. The article shall withstand 5 dips of one minute each.
(4). MASS OF GALVANISED COATING :- (a)Mass before and after galvanizing :- The mass of coating may be determined by
weighing the article before and after galvanizing , subtracting the first mass from the second and dividing the result by the coated surface area. The first mass shall be determined after pickling, rinsing and drying; and the second after cooling to the ambient temperature.
(b) Stripping method :- Average mass of coating shall be determined by
stripping the entire article in accordance with IS : 6745-1972 . If the surface area of the entire article cannot be measured easily or if the article is inconveniently large , a specimen of 100 sq. cm. area may be cut from each of the three samples ( 90 cm long test piece in case of masts) and stripped.
M = (M1-M2 ) X10^6 A M = mass of zinc coating, in g/m2, of surface. M1 = original mass, in g, of test piece. M2 = mass in g, of stripped test piece, and A = coated area of the test piece, in mm2.
(c) Magnetic thickness gauge method :- For large products such as poles, towers, structural
shapes and castings the average weight of the coating shall be determined by a magnetic thickness gauge.
Before making the measurement the gauge shall
be calibrated by measuring the thickness of zinc coating on a test panel and comparing the measured value with the value obtained by stripping method on the same piece.
In case of masts etc. readings shall be taken along the length at 100 mm interval and in approximate centre of the flange and then averaged to give a single figure for thickness of coating.
For castings etc. at least 5 readings may be taken at convenient locations nearly in the centre.
Thickness, in micro-meters, when multiplied by 7.047 would give the average mass of zinc coating (g/m2). Three articles in each lot of up to 100 shall be tested in this manner. Thickness shall not be less than the minimum.
value specified in Clause 4.1. [i.e 1000 g/m2]
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