Bonding Behavior and Mechanism of Composite Interface Between Carbon Steel/Stainless Steel Laminates at Different Temperatures and Strain Rates

Compared to hot roll and explosive bonding, there are relatively few studies on warm/cold roll bonding under low temperature conditions. In this article, the warm/cold roll bonding simulation experiment is conducted to research the deformation, interface bonding rate, microstructure, element diffusion behavior, metallographic structure, and phase of carbon steel/stainless steel. The results show that the plastic deformation remains consistent below 400 °C but exhibits temperature sensitivity above 400 °C. The lower strain rate can increase the bonding rate, while insulation treatment may reduce the bonding rate. The formation of cracks is inhibited at 25 °C and 45% reduction rate due to the challenge of cracking the surface oxide film. Temperature significantly affects bonding, with improved performance observed above 600 °C. Uneven element distribution of bonding area may be related to the precipitated compounds, while insulation treatment increases the mutual diffusion ability of elements. The increase in temperature leads to an increase in pearlite, a decrease in ferrite, and decarburization occurs within the carbon steel matrix. The carbon elements diffuse from carbon steel to the surface of stainless steel. The increase in temperature increases the content of surface compounds. Temperature significantly affects the overall plastic deformation ability of bimetallic materials. The high temperature decreases the bonding rate of the bimetallic material. The surface of the original carbon steel is tested to contain Fe, Ni–Cr–Fe, and Fe–Cr. As the temperature increases, the compound content significantly increases. Among them, Fe, Ni–Cr–Fe, and Fe–Cr represent the element name, not an abbreviation.