L.B. Pervukhin

EXPLOSIVE WELDING: THEORY AND PRACTICE

СВАРКА ВЗРЫВОМ: теория и практика

EPNM–2010

The analysis of defects arising in the course of industrial production of bimetal by explosion

welding

Distribution of joint durability to tearing off on length of sheet.

Defects in clad sheet: faulty fusion at the initial stages, worm-holes, local tear-out of clad material

«свищи», непровары вздутие

250

250

Change of joint durability on the sample length.

Class on continuity of layers joint

ГОСТ 10885-85

The defect areasm2 Defect kind

Marks of steels, the size (mm)

09Г2С+Тр316 Тi23(20+3)х1400х5900

09Г2С+Тр32145(41+4)х1400х5900

Quantity of sheets

In total

The defective

In total

The defective

I 10-50

Faulty fusion at the initial stages

51

0

99

0

Local tear-out 5 3Worm-holes 1 0

II 20-100

Faulty fusion at the initial stages

0 0

Local tear-out 7 4Worm-holes 1 2

III 50-250

Faulty fusion at the initial stages

51 99

Local tear-out 5 4Worm-holes 2 3

The scheme of joint formation

Method of "traps".

The surface of traps after welding of the titan with a steel in argon is absent a covering. In this photo machining traces are visible.

The surface of a trap after welding of the Ti+Steel on air. The covering from a mix oxygen the titanium is observed on a surface.

Fe, Fe3N

The scheme of calculation of shock-compressed gas area ahead of a contact point

Two problems are in common solved: -Problems about the moved piston, define of gas parameters for shock-wave;-Problems about flow out velocity of gas from a welding gap;

Vk – the contact point velocity ; Р0 – atmospheric pressure; Р1 – pressure in the shock-compressed gas υ - flow out velocity of gas from a welding gap; l – length of shock-compressed gas area

mgr - The grasped weight of air

mex - The expiring weight of air

υ

υ

Vk

constdt

dm

dt

dmexgr

Plastic deformation in the process of joint

formation.

P – давлениеσд – динамический предел прочности

l –длина линии соединения, l0 – длина проекции

Activation time of shock-compressed gas area is 0.9 · 10-4 s Activation time of plastic deformation area is 1 · 10-7 s

ε= l / l0p>>σд

At pressure welding Our suggestion

1. Formation of physical contact

2. Surface activation

3. Volumetric interaction

1. Cleaning and surface activation of welded plates occurs due to the interaction of shock-compressed gas and plasma stream formed at high-speed flow and plastic deformation at formation of a deformation hillock in the localised zone the limited isobar of high pressures

2. Formation of physical contact and joint in contact point

3. Volume interaction with joint formation and plastic deformation behind a contact point

Sequence of joint formation

Technological bases of industrial manufacture

• Choice of the scheme of welding with the account of properties of welded materials, features of narrow sides deformation and scraps of plating sheet

• Rational technology of surfaces preparation of initial materials and assemblage of packages

• Use as explosive mixtures of microporous ammonium-nitrate + diesel oil .

• Minimising of influence of external factors for the account of performance of all operations on explosion welding preparation in shop. (On range the apportion of explosive is made only.)

• Quality assurance at all stages of manufacture of bimetal.

Class on continuity of layers

joint ГОСТ

10885-85

The defect areasm2

Defect kind

Marks of steels, the size (mm)09Г2С+Тр316 Тi

23(20+3)х1400х590009Г2С+Тр321

45(41+4)х1400х5900Quantity of sheets

In total

The defective

In total

The defective

I 10-50

Faulty fusion at the initial stages

208

0

21

0

Local tear-out 3 1Worm-holes 1 0

II 20-100

Faulty fusion at the initial stages

0 0

Local tear-out 0 0Worm-holes 0 0

III 50-250

Faulty fusion at the initial stages

0 0

Local tear-out 0 0Worm-holes 0 0

Results of manufacture of bimetal on advanced technology.

Ready bimetal

After explosion welding

After heat treatment and editing

Industrial production of bimetals by explosion welding in Moscow region provides with:

• The high quality confirmed with the certificate at a competitive price;

• All-year industrial production;• Deadlines of performance of works from

reception of the order before delivery;• Maintenance on request of the customer of a full

cycle of manufacture, including heat treatment, furnish and carrying out of tests for conformity to requirements of standards and specifications.

Co-productionCo-production««Bitrub International LtdBitrub International Ltd » » and FKP NIIand FKP NII « «GeodeziyaGeodeziya»»

Quality of clad metals is provided with:

On-receipt inspection of raw materials• Manufacture technology• Control system of technological parameters during all manufacturing

stages

Finished clad metals are subjected to the next modes of inspection:

• Ultrasonic checkout of joint continuity• Checkout of joint tearing strength, shearing strength and bending

strength• Ultrasonic and metallographic checkout of clad layer thickness• Checkout of deflection from flat surface accuracy• Checkout of mechanical properties of base layer according to

Customer’s requirements

The basic documents regulating quality of the bimetal received by explosion welding

1. ГОСТ 10885-85 2. ТУ 27.32.09.010-2005 «Two-layer corrosion-resistant

sheet steel produced by explosion welding »3. ТУ 27.81.09.009-2005 «Two-layer feedstocks Steel +

Titanium obtained by explosion welding » Foreign analogues1. NC 501 General Specificacion(Франция)2. AD Merkblatt W8, Iuli 1987, спецификация 1264 от

4.85.