预奥氏体化对中MnTRIP钢组织及力学性能的影响

摘要

为了提高钢的综合力学性能，用盐浴法对中Mn TRIP钢进行了热处理。采用SEM、TEM、XRD和拉伸测试研究了预奥氏体化处理对中Mn TRIP钢显微组织及力学性能的影响。实验结果表明：全马氏体冷轧态组织经两相区退火处理后，会析出大量渗碳体颗粒，随着退火时间延长，渗碳体颗粒逐渐溶解，马氏体组织逐渐转变为奥氏体和铁素体双相片层状组织；而在两相区退火处理前添加两相区预奥氏体化处理后，渗碳体析出被有效抑制，双相片层组织迅速形成；相比于常规两相区退火处理，预奥氏体化处理能够提高组织中残余奥氏体体积分数和综合力学性能。%To improve the comprehensive mechanical properties of medium Mn TRIP steel, salt bath heat treatment was used. The influence of intercritically preaustenitize treatment on microstructure and mechanical properties of the steel were studied by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and tensile testing. The experimental result indicated that the cold-rolled full martensite structure was gradually transformed into a lamellar ferrite and austenite duplex structure and large amount of cementites were precipitated and then dissolved during intercritical annealing process. However, after preaustenitized intercritically before intercritical annealing, precipitation was suppressed and lamellar duplex structure was formed quickly, and the volume amount of retained austensite and mechanical properties was improved as well.