Structural changes in metastable austenitic steel during equal channel angular pressing and subsequent cyclic deformation

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

卷:723

Article

Dobatkin, S. V.^1,2  Skrotzki, W.³  Rybalchenko, O. V.^1,2  Terent'ev, V. F.¹  Belyakov, A. N.⁴  Prosvirnin, D. V.¹  Raab, G. I.⁵  Zolotarev, E. V.² 

[1] RAS, AA Baikov Inst Met & Mat Sci, Leninsky Prospect 49, Moscow 119334, Russia

[2] Natl Univ Sci & Technol MISIS, Lab Hybrid Nanostruct Mat, Leninsky Prospect 4, Moscow 119991, Russia

[3] Tech Univ Dresden, Inst Solid State & Mat Phys, Haeckelstr 3, D-01062 Dresden, Germany

[4] Belgorod State Univ, Pobeda St 85, Belgorod 308015, Russia

[5] Ufa State Aviat Tech Univ, Inst Phys Adv Mat, K Marx St 12, Ufa 450000, Russia

关键词: Stainless steel;    Equal channel angular pressing;    Ultra-fine grained structure;    Deformation-induced martensite;    Twinning;    Mechanical and fatigue properties;   

DOI  :  10.1016/j.msea.2018.03.018

来源: Elsevier

【 摘 要 】

The paper reports a substantial improvement of the static and cyclic strength of a Cr-Ni-Ti austenitic stainless steel nanostructured by equal channel angular pressing (ECAP). After ECAP at room temperature or 673 K, the mean grain size decreased from 14 inn to 430 not or 940 nm, respectively; corresponding ultimate tensile strength increased from 610 MPa to 1230 MPa or 940 MPa, and the fatigue limit increased from 275 MPa to 375 MPa or 475 MPa. These enhanced strength properties result from the grain refinement assisted by the intensive twinning in the austenite during ECAP at room temperature and 673 K as well as partial martensitic transformation during ECAP at room temperature. Moreover, the partial martensitic transformation and an increase in the fraction of high angle grain boundaries during subsequent high-cycle fatigue tests were particularly favorable for the improvement of fatigue properties.

【 授权许可】

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