Engineering mechanical properties by controlling the microstructure of an Fe-Ni-Mn martensitic steel through pre-cold rolling and subsequent heat treatment

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:804

Article

Koohdar, Hamidreza¹  Hakimipour, Pouya²  Jafarian, Hamid Reza¹  Langdon, Terence G.³  Nili-Ahmadabadi, Mahmoud^2,4 

[1] Iran Univ Sci & Technol IUST, Sch Met & Mat Engn, Tehran, Iran

[2] Univ Tehran, Sch Met & Mat Engn, Coll Engn, Tehran, Iran

[3] Univ Southampton, Mat Res Grp, Dept Mech Engn, Southampton SO17 1BJ, Hants, England

[4] Univ Tehran, Ctr Excellence High Performance Mat, Sch Met & Mat Engn, Coll Engn, Tehran, Iran

关键词: Deformation-induced austenite;    Fe-Ni-Mn martensitic Steel;    Microstructure control;    Post-deformation intercritical annealing;    Reverse transformation;   

DOI  :  10.1016/j.msea.2021.140760

来源: Elsevier

【 摘 要 】

Experiments were conducted to examine the effects of prior cold rolling and subsequent heat treatment on the microstructure, phase evolution and mechanical properties of an Fe-10Ni-7Mn martensitic steel. The results show that 70% cold rolling leads to deformation-induced austenite formation in the microstructure and reduces the size of the martensite blocks. Prior cold rolling increases the reversed austenite volume fraction under post-deformation intercritical annealing (PDIA) at 600 degrees C compared with the solution annealed condition. Electron back scattering diffraction and dilatometric studies showed that under PDIA there is a reverse transformation of martensite to austenite through a sequential combination of martensitic and diffusional mechanisms. There is also a precipitation of theta-NiMn particles in the PDIA specimen after subsequent ageing leading to an increase in the ultimate tensile strength in tensile testing. Cyclic tensile testing revealed pseudoelastic behavior in the cold-rolled specimen but this disappeared after PDIA and appeared again after subsequent ageing.

【 授权许可】

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