Research on the interfacial microstructure of three-layered stainless steel/Ti/low-carbon steel composite prepared by explosive welding

The stainless steel/Ti/low-carbon steel trimetallic composite plate was successfully fabricated by the explosive welding technique using honeycomb aluminum structure low detonation velocity emulsion explosive. The interfacial microstructure characterizations, elemental distribution, phase transformation and hardness were characterized using optical microscopy (OM), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD) and micro-hardness tester. The results indicated that the trimetallic sheet of stainless steel/Ti/low-carbon steel was successfully welded without visible defects and have an excellent bonding quality. The Ti/;ow-carbon steel joining interface had a typical wavy structure and formed about 3 µm thick transition layer. The stainless steel/Ti joining interface had an almost flat structure; meanwhile, the phase transformation of Fe and Ti and the texture occurred at the joining interfaces. The hardness increased near the welding interface and sharply increased in the melted zones.