Influence of final rolling temperature on microstructure and properties of stainless steel/carbon steel clad plate

This paper focuses on the problems of uncoordinated microstructure in each layer and difficult control of interfacial microstructure during the hot roll-bonding process of 316L stainless steel and Q370qE carbon steel. The influence of the final rolling temperature on the microstructure and properties of the stainless steel clad plate is investigated. The microstructure of the clad plate is analyzed by metallographic microscope， scanning electron microscope， transmission electron microscope， and energy dispersive spectrometer. The mechanical properties are performed based on the interface tension-shear and tensile tests. The results show that the higher the final rolling temperature， the larger the thickness of the decarburization layer and carburization layer in the interface area of the clad plate， while the diffusion distance of Cr and Ni elements first increases and then decreases. When the final rolling temperature is 840 ℃， the carbon steel layer is composed of proeutectoid ferrite， bainite， and sorbite， and the stainless steel layer is composed of austenite with several fine recrystallized grains. The thickness of the decarburization layer is 40 μm， and the thickness of the carburization layer is 35 μm. With the increase of the final rolling temperature， the interface tension-shear strength of the clad plate first increases and then decreases， while the yield strength and tensile strength both increase， and the increase rate slows down at high temperatures. The tension-shear fracture position of the clad plate is located in the decarburization layer of the carbon steel， and the fracture morphology of tensile shows interface delamination. Therefore， the clad plate final rolled at 840 ℃ achieves the best mechanical performance， with the interface tension-shear strength of 339 MPa， the yield strength of 497 MPa， the tensile strength of 594 MPa， and the elongation after fracture of 18.6%， respectively.