The effect of explosive welding parameters on metallurgical and mechanical interfacial features of Inconel 625/plain carbon steel bimetal plate

Like all cladding methods, interfacial features dominate the ultimate mechanical and metallurgical behavior of explosive cladded samples. Therefore, knowing the effect of explosive welding parameters on interfacial characteristics can be helpful in adjusting the welding parameters to obtain final desired properties. The present study aims to relate the load ratio and standoff distance as two main explosive welding parameters to interfacial features of explosive cladded Inconel 625/plain carbon steel bimetal plate such as interfacial structure, interfacial local melting phenomenon, localization of plastic strain, hardness variation across the interface and adhesion strength. As the results indicate, low impact energies are accompanied by linear interfacial structure, and increasing the impact energy initiates the waves at the interface. However, excessive impact energies lead to spoiling the wavy structure locally. Moreover, by raising the impact energy through increasing the load ratio and standoff distance, the locally melted zones appear in the Inconel side in vicinity of the interface. Higher impact energies promote the continuity of these interfacial cast layers. Though chemical elements of two materials are mixed together in these regions, no sign of intermetallic compounds formation is observed. According to the obtained results, raising the impact energy localizes the plastic deformation of steel side, resulting in the formation of adiabatic strain bands (ASB). The microhardness profiles reveal the hardening effect of collision in the vicinity of the interface with the exception of samples where the localization of strain in steel side hinders the hardening effect. Furthermore, the results of the shear test show that adhesion strength possesses an optimum value versus the increment of impact energy. By raising the load ratio and the standoff distance, the adhesion strength improves, but applying excessive collision energies drops this value significantly.