贝氏体区热处理对马氏体基体冷轧TRIP钢组织与性能的影响

Effects of Heat Treatment in Bainite Region on Microstructure and Property of Martensite Matrix TRIP Steel

对低碳硅锰试验钢进行水淬和随后的两相区退火与贝氏体区等温处理,利用光镜对热处理后的显微组织进行观察分析,通过拉伸试验测试了热处理后的力学性能,并采用X-ray衍射分析方法检测了拉伸前后残余奥氏体含量的变化。结果表明,热处理后的显微组织是铁素体、贝氏体与残余奥氏体的复合组织,随着贝氏体区等温温度的提高和等温时间的延长,残余奥氏体的体积百分数存在一极大值,在400℃等温5min时残余奥氏体的相对含量最多,此时具有最大的强度、塑性和强塑积。

The water quenching and subsequent intercritically annealing and isothermal treatment in bainite region for low carbon Si-Mn experimental steel were carded out.The microstructure at different heat treatment was analyzed by OM.The mechanicai properties of experimental steel after heat treatment were tested through the tensile experiment. The change of content of retained austenite before and after tension was detected using the analytical method of X-ray diffraction.The results show that low carbon Si-Mn experimental steel is multi-phase microstruture after heat treatment, which is mainly made up of ferrite,bainite and retained austenite,the volume percent of retained austenite presents extreme point with the increase of constant temperature and the prolong of constant time in bainite region, which reaches maximum value holding 5 min at 400℃ and has maximal strength,plasticity and product of strength and plasticity.