回火温度对COST-FB2转子钢析出相与力学性能的影响  

Tempering temperature effect on precipitation and properties of COST-FB2 rotor steel

作　　者：殷会芳 杨钢[1] 赵吉庆[1] YIN Hui-fang;YANG Gang;ZHAO Ji-qing(Institute of Special Steels,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]钢铁研究总院特殊钢研究所,北京100081

出　　处：《钢铁》2021年第5期91-97,121,共8页Iron and Steel

基　　金：国家重点研发计划资助项目(2016YFB0300203)。

摘　　要：为了调整COST-FB2转子钢的强韧性,采用OM、SEM和TEM等手段研究了回火温度对COST-FB2转子钢的析出相类型与力学性能的影响。结果表明,随着回火温度由350℃升高到750℃,试验钢的强度、硬度不断下降,塑性和冲击功上升;试验钢350℃和570℃回火后的高强低韧性可通过再次在700℃回火改善。淬火后COST-FB2转子钢中的残余奥氏体,可通过在570℃回火消除;在350℃和570℃回火后马氏体板条内部有大量针状的M_(3)C,700℃回火后的显微组织中M_(3)C消失,M_(23)C_(6)在原奥氏体晶界和马氏体板条界上析出,750℃回火后晶界上的M_(23)C_(6)有聚集粗化的现象,部分马氏体板条存在回复现象。The effects of tempering temperature on the microstructure and properties of COST-FB2 rotor steel was investigated by OM,SEM and TEM to adjust the strength and toughness of COST-FB2 steel.The results show that with the increase of tempering temperature,the strength and hardness of the tested steel decreases continuously,while the plasticity and impact energy increase;the total displacement of oscillograph at room temperature increases with the increase of tempering temperature.The high strength and low toughness of the tested steel after tempering at 350℃ and 570℃ can be improved by tempering at 700℃ again.The residual austenite in COST-FB2 rotor steel after quenching can be eliminated by tempering at 570℃.There are no M_(3)C in martensitic lath after quenching with oil cooling.There are a large number of needle-like M_(3)C within martensitic lath of the tested steel after tempering at 350℃ and 570℃.M_(3)C phase disappeared and M_(23)C_(6) precipitates at prior austenite grain boundary and martensite lath boundary after tempering at 700℃.There is aggregation and coarsening of M_(23)C_(6) at prior austenite grain boundary,and some martensite lath recovered.

关 键 词：回火温度 COST-FB2转子钢 显微组织 力学性能 M_(3)C相 M_(23)C_(6)相 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG156.5[金属学及工艺—金属材料]