Micromechanics and microstructure evolution during in situ uniaxial tensile loading of TRIP-assisted duplex stainless steels

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

卷:734

Article

Tian, Ye¹  Lin, Sen¹  Ko, J. Y. Peter²  Lienert, Ulrich³  Borgenstam, Annika¹  Hedstrom, Peter¹ 

[1] KTH Royal Inst Technol, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden

[2] Cornell Univ, Cornell High Energy Synchrotron Source, Ithaca, NY 14853 USA

[3] DESY, DESY Photon Sci, D-22607 Hamburg, Germany

关键词: Synchrotron x-ray diffraction;    in situ tensile loading;    Duplex stainless steel;    Load partitioning;    TRIP-assisted steel;    Micromechanics;   

DOI  :  10.1016/j.msea.2018.07.040

来源: Elsevier

【 摘 要 】

Transformation-induced plasticity (TRIP) assisted duplex stainless steels, with three different stabilities of the austenite phase, were investigated by synchrotron x-ray diffraction characterization during in situ uniaxial tensile loading. The micromechanics and the deformation-induced martensitic transformation (DIMT) in the bulk of the steels were investigated in situ. Furthermore, scanning electron microscopy supplemented the in situ analysis by providing information about the microstructure of annealed and deformed specimens. The dependence of deformation structure on austenite stability is similar to that of single-phase austenitic steels with shear bands and bcc-martensite (alpha') generally observed, and blocky alpha' is only frequent when the austenite stability is low. These microstructural features, i.e. defect structure and deformation-induced martensite, are correlated with the micro- and macro-mechanics of the steels with elastoplastic load transfer from the weaker phases to the stronger alpha', in particular this occurs close to the point of maximum rate of alpha' formation. A clear strain-hardening effect from alpha' is seen in the most unstable austenite leading to a pronounced TRIP effect.

【 授权许可】

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