20MnCrNi2MoRE钢贝氏体回火过程  

Bainite tempering process of 20MnCrNi2MoRE steel

作　　者：侯敬超[1] 计云萍[1] 刘宗昌[1] 刘新华[1,2] 任慧平[1,2] 

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：《材料热处理学报》2015年第1期114-118,共5页Transactions of Materials and Heat Treatment

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

摘　　要：针对20MnCrNi2MoRE低合金耐磨铸钢,采用洛氏硬度计、扫描电镜和透射电镜观察分析其在200~650℃范围内的回火转变过程。结果表明,20MnCrNi2MoRE钢铸态组织为粒状贝氏体,200℃回火时,贝氏体铁素体条首先发生变化,500℃回火时,在贝氏体铁素体条内、晶界及位错处观察到有碳化物析出。300℃回火时观察到(M/A)岛发生分解,650℃回火时(M/A)岛已经完全分解。低于500℃回火时,硬度变化不大,500℃以上回火时,由于位错密度降低和碳化物聚集长大,使硬度显著降低。Tempering transformation of 20 Mn Cr Ni2 MoRE low-alloy wear-resistant cast steel at 200-650 ℃ was investigated by Rockwell apparatus,scanning electron microscopy( SEM) and transmission electron microscope( TEM). The results show that the microstructure of 20 Mn Cr Ni2 MoRE as-cast steel is granular bainite. The bainitic ferrite first transforms during tempering at 200 ℃. After tempering at500 ℃,the carbide precipitation is observed in bainitic ferrite,grain boundary and dislocation. The( M / A) islands decompose during tempering at 300 ℃. When tempering temperature increases to 650 ℃,the( M / A) islands have decomposed totally. When the tempering temperature is lower than 500 ℃,the change of hardness is not obvious. When the tempering temperature is higher than 500 ℃,the hardness reduces obviously because of the decrease of dislocation and the gathering and growing up of carbides.

关 键 词：20MnCrNi2MoRE钢 贝氏体 (M/A)岛 碳化物析出 硬度 

分 类 号：TG161[金属学及工艺—热处理]