Meso and microscale clad interface characteristics of hot-rolled stainless steel clad plate
Abstract Stainless steel clad plate containing corrosion-resistant 304 stainless steel cladding and Q235 carbon steel substrate has been successfully fabricated by vacuum hot rolling at 1150 °C. The interface characteristics, microstructure, alloy element distribution and precipitation phases of clad plate were investigated by SEM, EPMA and TEM analysis in detail. Due to the carbon element diffusion, a decarburized layer (60–80 μm) and a carburized layer (20–40 μm) were formed at the carbon steel substrate and stainless steel cladding beside the interface, respectively. The uphill diffusion and interface peak value of carbon element are attributed to the differences in the diffusion velocity and solubility of carbon element in the substrate and cladding. Concentration gradient and diffusion coefficient between Cr and Ni elements are different, leading to different diffusion distances. Meanwhile, the grain boundaries of carburized layer were surrounded by Cr 23 C 6 particles. The interface with a thickness of 300–400 nm contains refined grains accompanying with many Cr 23 C 6 and MnSi 2 O 4 , SiO 2 particles. The sufficient alloy element diffusion behavior and interface oxides, precipitation phases lead to a high interface bonding shear strength (389 MPa).