【摘要】 对S13Cr马氏体不锈钢进行1000℃热挤压和热轧变形，随后在615℃回火处理，采用XRD、TEM和拉伸试验进行组织表征和力学性能测试，结合穿透式广角原位X射线衍射仪研究了变形储能对逆变奥氏体形成动力学及材料强塑性的影响。结果表明，相比于热轧制变形，热挤压变形引入了更多弹性能，因此试样具有更高的强度。在615℃回火6 h后，与热轧试样相比，热挤压试样中逆变奥氏体含量更高。两种热变形条件下形成的逆变奥氏体形态和成分相近。随回火时间延长，材料强度逐渐下降，伸长率上升，同时逆变奥氏体含量呈先增后减少的趋势。在回火初期形成的逆变奥氏体中观察到缠结位错和层错带，随回火时间增加，弹性应变能逐渐释放，奥氏体中的变形亚结构减少。弹性应变能高的区域有利于逆变奥氏体的形成，热挤压引入的高弹性储能是逆变奥氏体形成动力学加快的主要原因。更多还原

【Abstract】 S13 Cr martensitic stainless steel was subjected to hot extrusion and hot rolling at 1000 ℃,followed by tempering at 615 ℃ ． The microstructure characterization and mechanical properties were investigated by XRD,TEM,and tensile testing. Effect of deformation-stored energy on the formation kinetics of reversed austenite and the strength and ductility of the material was investigated by in-situ wide-angle Xray diffraction. The results indicate that the hot extruded specimen exhibits higher strength compared to the hot rolled one,as hot extrusion deformation introduces more elastic energy. After tempering at 615 ℃ for 6 h,the hot extruded specimen contains a higher volume fraction of reversed austenite than the hot rolled specimen. The morphology and composition of the reversed austenite formed under the two deformation conditions are similar. With prolonged tempering time,the strength of the steel gradually decreases while its elongation increases. The volume fraction of reversed austenite shows a trend of increasing first and then decreasing. Dislocation tangles and stacking fault bands are observed in the reversed austenite formed during the early stage of tempering. As the tempering time increases,the elastic strain energy is gradually released,leading to a reduction of deformation-induced substructures in the austenite. Zones with high stored elastic strain energy favor the formation of reversed austenite,and the higher elastic energy introduced by hot extrusion is the primary factor for the accelerated formation kinetics of reversed austenite.更多还原