L.B. Pervukhin EXPLOSIVE WELDING: THEORY AND PRACTICE СВАРКА ВЗРЫВОМ: теория и практика EPNM–2010
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.