稀土对20MnCrNi2Mo铸钢贝氏体回火过程中(M/A)岛分解的影响  

Effect of Rare Earth on Decomposition of (M/A) Islands in Bainite of 20MnCrNi2Mo Cast Steel during Tempering Process

作　　者：计云萍[1,2] 侯敬超[2] 任慧平[1,2,3] 

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]上海大学材料科学与工程学院,上海200072 [3]内蒙古自治区白云鄂博矿多金属资源综合利用重点实验室,内蒙古包头014010

出　　处：《稀土》2016年第1期8-12,共5页Chinese Rare Earths

基　　金：国家自然科学基金项目(51261018);内蒙古自然科学基金项目(2012MS0805);内蒙古科技大学创新基金项目(2011NCL037)

摘　　要：针对未加稀土与添加稀土的20MnCrNi2Mo耐磨铸钢,对其粒状贝氏体组织分别进行200℃-600℃各自保温1 h的回火处理,采用QUANTA400环境扫描电镜观察试样经不同温度回火后（M/A）岛的变化,采用D8ADVANCE X射线衍射仪对不同温度回火后试样中残留奥氏体量进行定量测定,分析稀土对回火过程中（M/A）岛分解的影响。结果表明,稀土对20MnCrNi2Mo钢粒状贝氏体回火过程中（M/A）岛的分解具有抑制作用,分析认为主要是固溶于钢中的稀土偏聚于界面处、降低了回火过程中碳原子的扩散速度所致。The granular bainite of 20MnCrNi2Mo wear- resistant cast steel without and with rare earth was respectively tempered at 200 ℃,300 ℃,400 ℃,500 ℃ and 600℃ for 1 h. The transformation of the（ M / A） islands during different temperature tempering processes was observed by QUANTA- 400 environmental scanning electron microscope and the retained austenite after different temperature tempering was measured quantitatively by D8 ADVANCE X ray diffracmeter. Then the influence of rare earth on the decomposition of（ M / A） islands during tempering process was investigated. The results show that rare earth can restrain the decomposition of（ M / A） islands in granular bainite of 20MnCrNi2Mo wear- resistant cast steel during the tempering process. The main reason is that the solid- solution rare earth in steel segregates on the interfaces and reduces the diffusion velocity of carbon atoms during the tempering process.

关 键 词：稀土 20MnCrNi2Mo耐磨铸钢 粒状贝氏体 回火 (M/A)岛 

分 类 号：TG156.5[金属学及工艺—热处理]