20Si2Mn2CrNi钢Ms点下的等温转变组织及其强韧性  

Isothermal microstructure and strength and toughness of 20Si2Mn2CrNi steel below Ms

作　　者：吴忠潮 周拥军 段宝玉[1] 侯渊[1] 呼云飞 高占勇[1] Wu Zhongchao;Zhou Yongjun;Duan Baoyu;Hou Yuan;Hu Yunfei;Gao Zhanyong(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou Inner Mongolia O14010,China;Fucheng Forge Company of Inner Mongolia First Machinery Group Co.,Ltd.,Baotou Inner Mongolia 014030,China;Inner Mongolia Huze Equipment Manufacturing Co.,Ltd.,Erdos Inner Mongolia 016062,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]内蒙古一机集团富成锻造有限责任公司,内蒙古包头014030 [3]内蒙古华泽装备制造有限公司,内蒙古鄂尔多斯016062

出　　处：《金属热处理》2023年第7期15-21,共7页Heat Treatment of Metals

基　　金：鄂尔多斯市科技重大专项(2021ZD工25-7);内蒙古自治区重点研发和成果转化项目(2022YFHH0098)。

摘　　要：采用热膨胀法研究了一种低碳低合金B/M复相高强20Si2Mn2CrNi钢在Ms点(386℃)附近等温淬火的相变动力学,运用K-M模型定性地计算了Ms点以下等温淬火时的马氏体体积分数,研究了试验钢在不同等温淬火工艺下的组织转变对其力学性能的影响规律。结果表明,试验钢在高于386℃等温时过冷奥氏体转变为上贝氏体,而在386℃以下等温时除形成马氏体外,还形成了与386℃以上奥氏体等温转变为贝氏体动力学一致的低温贝氏体。试验钢在300℃等温淬火时,马氏体体积分数为91.74%,硬度为41.7 HRC,冲击吸收能量为91.7 J,具有较好的强塑性综合力学性能,这与贝氏体组织与马氏体组织良好的协调变形有关。Phase transformation kinetics of a low carbon low alloy B/M dual-phase high-strength 20Si2Mn2CrNi steel during isothermal quenching around 386 ℃ was studied using thermal expansion method.The volume fraction of martensite below the Ms point during isothermal quenching was qualitatively calculated using the K-M model,and the influence of microstructural transformation under different isothermal quenching processes on the mechanical properties was investigated.The results show that the experiment steel transforms to upper bainite when it is isothermally quenched above 386 ℃,while forming not only martensite but also low-temperature bainite with the same kinematics as bainite transformation from austenite above 386 ℃ when it is isothermally quenched below 386 ℃.When the experimental steel is isothermally quenched at 300 ℃,the volume fraction of martensite is 91.74%,the hardness is 41.7 HRC,and the impact absorbed energy is 91.7 J,showing good comprehensive mechanical properties of strength and plasticity due to the well-coordinated deformation between bainite and martensite microstructure.

关 键 词：20Si2Mn2CrNi钢 贝氏体 马氏体 等温淬火 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]