30MnNiCuMoB-RE铸钢的连续冷却相变动力学研究  

The Continuous Cooling Transformation Kinetics of 30MnNiCuMoB-RE Cast Steel

作　　者：李传维[1] 刘泽盛 顾剑锋[1] 董安平[1] 张梅 何耀宇 LI Chuanwei;LIU Zesheng;GU Jianfeng;DONG Anping;ZHANG Mei;HE Yaoyu(School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Technology Research Institute,Inner Mongolia First Machinery Group Co.,Ltd.,Baotou 014030,Inner Mongolia China)

机构地区：[1]上海交通大学材料科学与工程学院,上海200240 [2]内蒙古第一机械集团有限公司工艺研究所,内蒙古包头014030

出　　处：《热处理》2023年第5期13-21,26,共10页Heat Treatment

基　　金：国家自然科学基金面上项目(No.52171042)。

摘　　要：采用淬火相变热膨胀仪测定了30MnNiCuMoB-RE铸钢890℃完全奥氏体化后以不同速度连续冷却时的膨胀曲线。通过金相检验和硬度测定研究了30MnNiCuMoB-RE铸钢在连续冷却过程中的相变动力学。结果表明:30MnNiCuMoB-RE铸钢在890℃完全奥氏体化后以0.01~100℃/s的速率冷却时,随着冷却速率的增大,奥氏体依次转变为铁素体、贝氏体和马氏体,铁素体转变温度区间为717~611℃,贝氏体转变温度区间为590~323℃,马氏体转变温度区间为313~168℃;从获得的连续冷却转变(CCT)曲线可知,随着冷却速率的降低,发生贝氏体相变的临界冷速为50℃/s,发生铁素体转变的临界冷速为0.5℃/s;由于钢中存在一定程度的偏析,以0.01~0.2℃/s的速率冷却时,奥氏体依次转变为铁素体和贝氏体,钢的组织不均匀;随着冷却速率的提高,钢的硬度从200 HV10提高至500 HV10。The expansion curves of 30MnNiCuMoB-RE cast steel during continuous cooling at different rates after complete austenititizing at 890℃were measured via a quenching transformation dilatometer.The kinetics of phase transformation of 30MnNiCuMoB-RE cast steel during continuous cooling were investigated by means of metallographic examination and hardness measurements.The results showed that(a)during the cooling at rates ranging from 0.01 to 100℃/s after complete austenitizing at 890℃,the austenite transformed successively into ferrite,beinite and martesite in the 30MnNiCuMoB-RE cast steel with the increase in cooling rate,with the transformation temperature range being 717 to 611℃for the ferrite,590 to 323℃for the bainite,and 313 to 168℃for the martensite;(b)from the obtained continuous cooling transformation(CCT)curve it was seen that with the decrease in cooling rate the critical cooling rate was 50℃/s for the bainite transformation and 0.5℃/s for the ferrite transformation;(c)due to a certain degree of segregation in the steel,during the cooling at rates of 0.01 to 0.2℃/s the austenite transformed successively into ferrite and bainite with the result that the steel exhibited inhomogeneous structure;and(d)as the cooling rate increased,the hardness of the steel increased from 200 to 500 HV10.

关 键 词：ZG30MnNiCuMoB-RE铸钢 冷却速率 显微组织 连续冷却转变(CCT)曲线 

分 类 号：TG151.2[金属学及工艺—热处理]