Study on the Effects of Explosive Covering on Explosive Welding of Stainless Steel to Steel

In order to improve the energy utilization ratio of explosives and reduce the noise and dust for explosive welding, honeycomb structure explosives covered by colloid water were put forward as explosive materials. Using 304 stainless steel and Q235 steel as flyer plate and base plate respectively, explosive welding tests were carried out with different covering thicknesses. The dynamic parameters in the collision process were obtained by experimental measurement and theoretical calculation. The microstructure of the bonding interface was observed through optical microscopy and analyzed by welding window. The results showed that, compared to the explosive welding without covering, the impact velocity of flyer plates was increased by 38.9%, 57.5% and 71.9% respectively when the covering thickness was 15mm, 30mm and 45mm. The impact velocity predicted by Gurney formulas was significantly larger than the measured value, however, after considering acceleration history, the calculated value was in good agreement with the experimental result. Metallographic analysis showed that wave bonding interfaces without defects such as voids and cracks were obtained when the welding conditions were within the welding window. However, voids and cracks were found at the bonding interfaces when the welding conditions were close and above to the upper limit of the welding window.