Interface formation and bonding mechanisms of hot-rolled stainless steel clad plate

Since the 1980s, vacuum hot rolling has been developed to fabricate the stainless steel clad plates by the Iron and Steel Institute of Japan. Herein, hot rolling is a widely used solid-state bonding process to join the carbon steel substrate and stainless steel cladding. In this paper, we provide a brief overview of the vacuum hot rolling process and effective parameters on the interface characteristics and shear strength of stainless steel clad plate. The effects of surface preparation condition, atmosphere condition, vacuum degree, rolling temperature, rolling reduction ratio, interlayer, heat treatment on the microstructure, interface characteristics and mechanical properties of stainless steel clad plate have been analyzed in detail. It is shown that the interface transition zone is formed due to the carbon diffusion, and the strong interface bonding is attributed to the sufficient alloy elements diffusion of Fe, Cr and Ni. Moreover, the interface shear strength and toughness are also affected by interfacial precipitation phase and multiple oxides. Finally, the present work concluded the bonding mechanism of hot-rolled stainless steel clad based on the oxide film theory, diffusion theory, recrystallization theory and three stage theory.