EXPLOSIVEE WELDING OF LARGE-SIZE SHEETS: SEAM QUALITY ISSUES

O.L. Pervukhina, T.A. Shishkin, I.V. Denisov, and L.B. Pervukhin (Russia)

Institute of Structural Macrokinetics and Materials Science RAS (ISMAN), Academician Osipyan str., 8, Chernogolovka, Moscow

Region, 142432, RUSSIA

Methods of testing the quality of the resulting explosion welding seam

Ultrasonic testing

Experimental study of wave generation

We explored the quality of explosive welding of steel (09G2S) to titanium alloy (VT1-0)

carried out at –15C with large sheets 31.5(26 + 5.5) 3300 3700 mm in their dimensions.

Metallographic specimens 25 and 100 mm wide were cut from the welded sheet at a pitch

of 300 mm; Measuring the size of the waves was performed using the magnifying glass

Brinell.

The pull strength of the seam was found to vary between 210 and 350 MPa

= 0.12 . . .0.24 mm

repers

L, mm

L, mm

Sheets elongation and Wavy structure of weld seam as a function of sheet length L

The results of ultrasonic testing

The size of the shock-compressed gas area / sheet length

The sample for the study

12900

8000 mm stable wave structure

sheet length, m

1

2

11

0

1

2

1

22

1к

Pv

sb

bsl

ρ0 – density of flowing gas, b – length of the contact line, P1 – pressure in the shock-compressed gas, Vк – contact point velocity, - velocity of the gas, l - extent of the zone of shock-compressed gas, s – distance from the contact point

h = 0.12 . . .0.24 mm

h = 0. . .1 mm

Investigation of the structure of the cladding sheet defective portion

1 layer dark fragile

2 layer bright, brilliant plastic

C O Na Al Si Cl Ti Cr Mn Fe Ni

1 5.31 22.60 1.06 1.05 0.44 7.06 1.05 52.41 9.01

2 6.01 37.08 2.00 0.86 2.31 3.44 47.25 1.04

3 3.42 41.64 1.45 1.41 1.30 1.02 1.21 48.54

4 2.13 43.10 1.19 0.71 52.86

1 layer microstructure

2 layer microstructure

O Al Si Cr Mn Fe Ni Total

1 0.61 0.59 0.42 7.17 1.23 86.78 3.20 100.00

2 1.30 1.81 1.11 0.84 1.73 92.97 0.24 100.00

2 layer microstructure

Сonclusions

• If the length of the field of shock-compressed gas increases the heating time of welded surfaces. This leads to rapid melting of the welded surfaces and halting the wave formation.