CAJ | 학술논문

采用Gleeble-3500热模拟试验机测定了不同温度下中锰钢的变形抗力，并通过分阶段拉伸、扫描电镜、电子背散射衍射、X射线衍射等实验手段，对温轧中锰钢中逆转变奥氏体的相变行为进行观察和分析。研究发现，热轧马氏体中锰钢经过600℃温轧及退火后，获得较多较稳定的残余奥氏体，从而实现强度859 MPa和延伸率36%的优良力学性能。拉伸变形前期，锯齿状流变应力现象明显，残余奥氏体提供持续的TRIP效应来提高塑性，此过程中尺寸较大的逆转变奥氏体稳定性差，变形时先发生转变；拉伸变形后期，锯齿状波动消失，超细晶铁素体和马氏体发生塑性变形，马氏体强化及铁素体中的位错强化为主要强化方式。
채용Gleeble-3500열모의시험궤측정료불동온도하중맹강적변형항력，병통과분계단랍신、소묘전경、전자배산사연사、X사선연사등실험수단，대온알중맹강중역전변오씨체적상변행위진행관찰화분석。연구발현，열알마씨체중맹강경과600℃온알급퇴화후，획득교다교은정적잔여오씨체，종이실현강도859 MPa화연신솔36%적우량역학성능。랍신변형전기，거치상류변응력현상명현，잔여오씨체제공지속적TRIP효응래제고소성，차과정중척촌교대적역전변오씨체은정성차，변형시선발생전변；랍신변형후기，거치상파동소실，초세정철소체화마씨체발생소성변형，마씨체강화급철소체중적위착강화위주요강화방식。
The deformation resistance of medium manganese steel at different temperatures was measured on a Gleeble-3500 thermo-simulator system. Reverted austenite transformation in medium manganese steel during warm rolling was investigated by means of tensile testing by stages, scanning electron microscopy (SEM), electron back scattered diffraction (EBSD), and X-ray diffraction (XRD). It is shown that warm rolling at 600℃and annealing after hot rolling result in more reverted austenite, and excellent mechanical properties are gained with 859 MPa strength and 36%elongation. In the earlier stage of tensile deformation, serrate flow stress behavior is obviously observed because of sustained TRIP effect produced by reverted austenite. During the deformation, reverted austenite with a larger grain size is prior to transform because its stability is poor. In the later stage of tensile deformation, serrate flow stress behavior disappears. Ultrafine grain ferrite and martensite undergo plastic deformation, and martensite strengthening and dislocation strengthening of ferrite become the main strengthening mechanism.