Effect of Heat Treatment on Microstructure and Mechanical Properties of Super Austenitic Stainless Steel Clad Plate

The N08367 / Q345R super austenitic stainless steel clad plate was prepared in vacuum rolling cladding process, and the effects of hot-rolling, quenching and tempering processes on its microstructure and mechanical property were analyzed. The results show that the decarburization layers of the carbon steel substrate increased significantly after heat treatment. In quenching process, the diffusion of the C element led to the precipitations of χ phase and intergranular carbides, while the metastable χ phase could be decomposed into more intergranular carbides after tempering process. An obvious interfacial martensite zone was formed by the interfacial diffusion of Cr, Ni, Mo and C elements. After tempering, the residual stress at the interface was reduced and the martensite at the interface was transformed into the tempered martensite. The nucleation, growth and recrystallization of new grains at the interface occurred at the 650 ℃ tempering, resulting in the formation of grains with the same orientation as the grains of substrates at the interface. The interfacial shear strengths of all samples were above 350MPa. The strength, plasticity and toughness of the substrate material of the clad plate tempered at 650 ℃ can meet national standard requirements. © 2023 Northeastern University. All rights reserved.