Effect of heat treatment on bonding characteristics and interfacial microstructures in explosively welded Ti/SUS430 stainless steel clad

摘要

Effect of heat treatment on bonding characteristics and interfacial microstructures in explosively welded titanium/SUS430 ferrite stainless steel clad was investigated. The average shear strength of the clad annealed at 1073K for 3.6 ks was 338MPa and was equivalent to about 60% of that of an as-welded clad. The strength of the clad annealed at 1073K gradually decreased to 242 MPa with increasing holding time up to 360 ks. The same tendency was obtained from the clad annealed at 1173K. On theother hand, the strength of the clad annealed at 1273K drastically decreased to 107MPa with increasing holding time up to 360ks. The clad annealed at 1073 and 1173K yielded TiC layer at the bonding interface, while the reaction layer in the clad annealed1273K consisted of TiC, FeTi, Fe{sub}2Ti and X (Fe{sub}29Cr{sub}13Ti{sub}8) from titanium side. It was noted that chromium existed in the Fe{sub}2Ti , which has wide solubility limit for chromium, and X compounds formed at the SUS430 side. The TiC layerin the former dads acts as a barrier for diffusion of titanium, iron and chromium across the bonding interface and prevents the growth of intermetallic compounds. The clad formed TiC layer at the bonding interface preserved high bonding strength evenafter prolonged annealing.