论文部分内容阅读
通过Gleeble热模拟实验研究了含0.038%Nb(质量分数)的热轧TRIP钢在高温奥氏体区的热加工工艺,借助光学显微镜、扫描电镜和透射电镜分析了组织演变和Nb的析出行为,并利用电感耦合等离子体发射光谱仪定量分析了Nb的固溶/析出程度.在1250℃奥氏体化5 min后添加Nb有70%固溶于奥氏体.在1000℃以上的奥氏体再结晶区变形过程中Nb的析出量仅占总固溶量的3%,不能有效抑制静态再结晶,奥氏体晶粒得到明显细化.在900℃的奥氏体未再结晶区变形前析出Nb量已达到总固溶量的9%,再结晶被抑制而获得拉长状奥氏体.奥氏体未再结晶区变形可促进铁素体转变并细化铁素体晶粒.再结晶奥氏体或形变奥氏体状态下冷却至650℃时分别有占总添加量的48%和40%的Nb仍以固溶态存在.
The hot working process of hot rolled TRIP steel containing 0.038% Nb in high temperature austenite region was studied by Gleeble thermal simulation experiment. The microstructure evolution and Nb precipitation behavior were analyzed by optical microscope, scanning electron microscope and transmission electron microscope. And the degree of solid solution / precipitation of Nb was quantitatively analyzed by inductively coupled plasma atomic emission spectrometry. After adding austenite at 1250 ℃ for 5 min, 70% of Nb was added to the austenite, and austenite at 1000 ℃ During the deformation of the crystalline zone, the amount of Nb precipitated accounts for only 3% of the total dissolved solids, which can not effectively suppress the static recrystallization and the austenite grains are obviously refined. Precipitation of the austenite non-recrystallized zone at 900 ℃ The amount of Nb has reached 9% of the total dissolved solids, recrystallization is inhibited to obtain elongated austenite austenite non-recrystallization zone deformation can promote ferrite transformation and refine ferrite grains. Recrystallization When cooled to 650 ° C in the austenite or deformed austenite state, 48% and 40%, respectively, of the total added amount of Nb still exists in a solid solution state.