Microstructure Characteristics of Interface in Hot-rolled 304/Q235B Clad Plate

Microstructural characteristics, element distribution, microstructure of transition layer at the bonded interface of hot-rolled 304/Q235B clad plate were studied by means of metallographic microscope, scanning electron microscope and transmission electron microscope. The results show that the microstructure near the interface of hot-rolled 304/Q235B clad plate consists of four regions:austenites in stainless steel matrix, transition layer with 5 μm thickness, ferrites with 50 μm decarburization layer and ferrites plus pearlites in carbon steel matrix. Diffusion region of alloying elements such as Cr, Ni, and C exists in the interface, and obvious element distribution curves are formed. The microstructure of transition layer contains lath martensite with high density dislocations, and there are a large number of fine needle-shaped carbides with the type of M3C in the martensite laths.