Enhanced interfacial strength and ductility of stainless steel/carbon steel laminated composite by heterogenous lamella structure

Interfacial performance of stainless steel/carbon steel (SS/CS) laminated composite is crucial for further manufacturing and application. Here, we reported a new strategy for fabricating the SS/CS laminated composites that composed of heterogeneous lamella structure at the cladding interface zone, by employing liquid–solid bonding and subsequent hot rolling. Different rolling temperatures were applied for comparison of the formation of heterogeneous lamella structure and their influences on the mechanical properties of the cladding interface, and the mechanisms of enhanced interfacial shear strength and ductility by the heterogenous lamella structure were discussed. A metallurgical bonding interface with intensive elements diffusion was obtained by liquid–solid bonding method, and coarse equiaxed grains and a wider decarburized layer formed at the cladding interface zone. Under rolling temperature of 900 °C, the mechanical incompatibilities of cladding interface zone and lower temperature resulted in heterodeformation and inefficient driving force of recrystallization, resulting in a heterogenous lamella structure consisted of hardened austenite region, coarse-grained ferrite region and fine-grained pearlite and ferrite region at the cladding interface zone of SS/CS laminated composite, which obviously improved the interfacial shear strength and ductility of the SS/CS laminated composites due to back stress strengthening and hardening.