系泊链用R4(22MnCrNiMo)钢CCT曲线测定及分析  

Determination and analysis of CCT curves of R4( 22MnCrNiMo)steel for mooring chain

作　　者：方光锦 Fang Guangjin(Xining Special Steel Co.,Ltd.,Xining Qinghai 810005,China)

机构地区：[1]西宁特殊钢股份有限公司,青海西宁810005

出　　处：《金属热处理》2020年第3期208-211,共4页Heat Treatment of Metals

基　　金：青海省重点企业技术创新项目(2019-JC-04)。

摘　　要：利用DIL805A型热膨胀仪测定R4(22MnCrNiMo)钢膨胀曲线,并结合金相、硬度检验绘制出试验钢的CCT曲线,研究不同冷却速度对该钢的组织转变影响。结果表明,R4(22MnCrNiMo)钢的临界转变点为:Ar3=819. 5℃,Ar1=778. 5℃;当冷速为0. 1~0. 5℃/s时,冷却得到的组织主要为下贝氏体+残留奥氏体+极少量马氏体;当冷速达到3℃/s时,显微组织中只有极少量下贝氏体组织存在;继续增大冷速,显微组织均为板条状、针状马氏体+残留奥氏体。The expansion curve of R4( 22 MnCrNiMo) steel was measured by DIL805 A thermal expansion instrument. CCT curves of the steel were drawn by metallographic and hardness test. The effects of different cooling rates on microstructure transformation of the steel were studied. The results show that the critical transition point of R4( 22 MnCrNiMo) steel is: Ar3= 819. 5 ℃,Ar1= 778. 5 ℃ . When the cooling rate is in the range of 0. 1-0. 5 ℃/s,the microstructure obtained by cooling is mainly lower bainite + retained austenite + small amount of martensite structure,only a small amount of lower bainite structure is obtained when the cooling rate reaches 3 ℃/s,as the cooling rate further increases,the microstructure is lath-like,needle-shaped martensite + residual austenite structure.

关 键 词：R4(22MnCrNiMo)钢 CCT曲线 相转变 显微组织 

分 类 号：TG115.21[金属学及工艺—物理冶金]