Welding induced residual stresses in explosion cladded AL-6XN superaustenitc stainless steel and ASME SA516-70 steel composite plates.

Explosion welding is a solid state joining process that allows the manufacturing of corrosion resistant structural composite materials in the form of plates. In the present work, composite bimetal plates of AL-6XN superaustenitic stainless steel and ASME SA516-70 carbon steel produced by explosion welded were studied. Post-weld annealing for stress relief was conducted at 600°C for 30 min and the materials were examined in both the as welded and heat treated conditions. The microstructure of the weld was characterized by optical and scanning electron microscopy and the variation of hardness across the cladded interface was determined by applying Vickers microhardness. The residual stresses generated by the explosion welding process were analyzed by X-ray diffraction using the sin2\j/ technique. The cladded interface exhibited a wavy morphology, characteristic of high bonding strength in explosion welds and the variation of hardness was found to be strongly influenced by strain hardening at the cladded interface. Elevated tensile stresses (700 ± 30 MPa) were present after explosion welding. Application of the proposed heat treatment allowed for significant stress relaxation, with a final tensile stress of 93 ± 10 MPa. [ABSTRACT FROM AUTHOR]