淬火和回火工艺对50MnB钢组织与性能的影响  

Effects of quenching and tempering process on microstructure and properties of 50MnB steel

作　　者：周宏亮[1] 胡楠[1] 杨弋涛[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200072

出　　处：《金属热处理》2016年第2期104-108,共5页Heat Treatment of Metals

基　　金：基金项目:教育部"卓越工程师教育培养计划"

摘　　要：为了优化50MnB钢热处理工艺,设计了水淬、盐水淬和油淬三种淬火冷却方式以及180、200、220℃三种不同回火温度。通过组织观察、力学性能测定、断口形貌观察、XRD物相分析探讨淬火方式和回火温度对50MnB钢组织性能的影响。结果表明,油淬是适宜的淬火方式,淬火组织均匀;回火组织由回火马氏体和少量碳化物组成,回火后仍保留马氏体板条形态。随着回火温度的升高,回火组织中的马氏体板条更细小,碳化物析出增加。同时,硬度和抗拉强度降低,伸长率增加。根据组织与性能试验结果,得出220℃是适合的回火温度。In order to optimize the heat treatment process of 50MnB steel,three quenching methods and three tempering temperatures as180 ℃,200 ℃ and 220 ℃ were designed in this study. The effects of quenching and cooling ways and tempering temperature on microstructure and properties of 50MnB steel were investigated by microstructure observation, mechanical property test and fracture morphology observation. The results show that oil quenching is a suitable quench-cooling way, the microstructure is homogeneous.Microstructure of the tempered samples is composed of tempered martensite and a few carbides,the martensite still kept the shape of lath.With the increase of tempering temperature,the microstructure becomes finer and precipitated carbides are increased,meanwhile,the hardness and tensile strength is reduced,the elongation is increased. According to the test results of microstructure and properties,it is concluded that 220 ℃ is a suitable tempering temperature for 50MnB steel.

关 键 词：50MnB钢 淬火方式 回火温度 力学性能 碳化物 

分 类 号：TG156.94[金属学及工艺—热处理]