Chro-austempering treatment of a medium-carbon high-strength bainitic steel
Man Liu1, Jun-yu Tian1,2, Feng Cai1, Cheng-gang Pan1, Guang Xu1
1 The State Key Laboratory of Refractories and Metallurgy, The Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, The Collaborative Innovation Center for Advanced Steels of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China 2 Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China
Chro-austempering treatment of a medium-carbon high-strength bainitic steel
Man Liu1, Jun-yu Tian1,2, Feng Cai1, Cheng-gang Pan1, Guang Xu1
1 The State Key Laboratory of Refractories and Metallurgy, The Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, The Collaborative Innovation Center for Advanced Steels of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China 2 Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China
摘要 The integrated processing of chromizing and austempering (termed chro-austempering) treatments was proposed. The microstructure and properties of a medium-carbon high-strength bainitic steel treated by chro-austempering treatments were investigated by metallography, scanning vibrating electrode technique, electrochemical workstation, and microhardness test. The results show that the high-strength bainitic steel with carbide-free bainite as matrix and the chromized layers on surfaces was successfully fabricated by chro-austempering treatment. The hardness of surface layers was about 3.5 times that of the bainite matrix. Meanwhile, the corrosion started from exposed bainitic matrix and proceeded along the depth direction, testifying that the surface corrosion resistance was significantly improved by chro-austempering treatment due to the formation of Cr7C3 and (Cr, Fe)7C3 on the surface.
Abstract：The integrated processing of chromizing and austempering (termed chro-austempering) treatments was proposed. The microstructure and properties of a medium-carbon high-strength bainitic steel treated by chro-austempering treatments were investigated by metallography, scanning vibrating electrode technique, electrochemical workstation, and microhardness test. The results show that the high-strength bainitic steel with carbide-free bainite as matrix and the chromized layers on surfaces was successfully fabricated by chro-austempering treatment. The hardness of surface layers was about 3.5 times that of the bainite matrix. Meanwhile, the corrosion started from exposed bainitic matrix and proceeded along the depth direction, testifying that the surface corrosion resistance was significantly improved by chro-austempering treatment due to the formation of Cr7C3 and (Cr, Fe)7C3 on the surface.
Man Liu,Jun-yu Tian,Feng Cai, et al. Chro-austempering treatment of a medium-carbon high-strength bainitic steel[J]. Journal of Iron and Steel Research International, 2023, 30(02): 317-327.
2023, Vol. 30 
