Atom probe study on microstructure change in severely deformed pearlitic steels: application to rail surfaces and drawn wires

38th Risø International Symposium on Materials Science

Takahashi, Jun^1

Advanced Technology Research Labs., Nippon Steel and Sumitomo Metal Corporation, 20-1 Shintomi, Futtsu-City, Chiba

293-8511, Japan^1

关键词: Atom probe tomography;    Cementite decomposition;    High-tensile steels;    Layered Structures;    Microstructural changes;    Microstructure changes;    Pearlitic rail steels;    Pearlitic steels;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/219/1/012007/pdf
DOI  :  10.1088/1757-899X/219/1/012007

来源: IOP

【 摘 要 】

Pearlitic steel is used as the material for high tensile steel wires, rails and wheels due to its high work hardening and wear resistance. These properties arise from a layered structure comprising deformable lamellar ferrite and hard lamellar cementite. This paper reviews the microstructural change in heavily drawn pearlitic steels wires and worn surfaces of pearlitic rails using atom probe tomography analysis. The cementite decomposition mechanism was elucidated for heavily drawn pearlitic steel wires. For pearlitic rail steels, atomic scale characterization of worn surfaces and of the white etching layer (WEL) were performed, and a mechanism for the formation of the WEL was proposed. The differences and similarities in microstructure and in the state of the cementite in these severely deformed pearlitic steels are discussed.