Abstract:425 steel is a resource-saving, ultra-purified ferritic stainless steel developed for the cold end of automobile exhaust system. Its chromium mass fraction is 15%, carbon and nitrogen are stabilized using Ti and Nb elements. The microstructure evolution and tensile properties of 425 steel after annealing at 880~1 000 ℃ were investigated by optical microscope, scanning electron microscope, electro-mechanical universal testing machines and electrochemical workstation, and the formability and corrosion resistance were compared with 409 and 439 steel. The results show that 425 steel has the best combination of microstructure and tensile properties after annealing at 960 ℃. The formability of 425 steel is equivalent to that of 439 and 409 steel, the pitting corrosion rate is slightly greater than that of 439 and significantly lower than that of 409 steel, and the pitting potential is between that of 409 and 439 steel. In general, 425 ultra-purified ferritic stainless steel has good plasticity, formability and corrosion resistance. It is an ideal material for cold end application of automobile exhaust system.
付金柱, 武敏, 李国平, 刘春来, 段秀峰. 超纯铁素体不锈钢425组织性能研究与评价[J]. 中国冶金, 2022, 32(6): 101-107.
FU Jin-zhu, WU Min, LI Guo-ping, LIU Chun-lai, DUAN Xiu-feng. Research and evaluation on microstructure and properties of ultra-purified ferritic stainless steel 425[J]. China Metallurgy, 2022, 32(6): 101-107.
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