Effect of Heat-Treatment on the Interface Microstructure of Explosively Welded Stainless Steel – Bronze Composite

Abstract

Analysis of structural variations taking place at the stainless steel (09Cr18Ni10Ti) - bronze (CuBe2Ni) interface obtained by explosive welding was conducted in the current work. The produced weld joint was post heat-treated in the temperature range from 500 to 800 °С. Microstructural characterizations were carried out using optical and scanning electron microscopy. The results of the analysis revealed the presence of 2 zones at the interface: mixing zone of bronze and stainless steel and a diffusion zone. The diffusion processes in the weld joint during heating were studied by the energy-dispersive analysis (EDX). EDX studies revealed that at 800 °С copper contained in bronze completely migrated from the diffusion layer to the mixing zone whereas iron concentration, on the contrary, increased in the diffusion layer. Voids appeared in the mixing zone of stainless steel and bronze due to the difference of diffusion coefficients of basic elements in the composite.