稀土对21-4N钢显微组织和力学性能的影响  

Influence of Rare Earth on Microstructure and Mechanical Properties of 21-4N Steel

作　　者：余式昌[1] 吴申庆[1] 燕纪全[1] 宫友军[2] 宫元生[2] 练明生[2] 叶刚[2] 成义军 柯红升 翟德建 

机构地区：[1]东南大学材料科学与工程系,江苏南京210096 [2]江苏申源特钢有限公司,江苏兴化225722

出　　处：《机械工程材料》2005年第6期33-35,51,共4页Materials For Mechanical Engineering

基　　金：国家火炬计划资助项目(2003EB030408)

摘　　要：研究了不同稀土加入量对21—4N钢显微组织和力学性能的影响。结果表明:适量混合稀土加入后,21-4N钢铸态树枝晶组织明显得到细化,偏析现象减轻,夹杂物尺寸变小,部分夹杂物形态由多边形向椭圆形转变。稀土能减轻轧制织构,改善碳化物的分布。随着稀土添加量的增加,常温(15℃)抗拉强度先是提高,然后略有下降,伸长率是逐步下降的。而适量的稀土(0%～0.20%)能提高21-4N钢高温(500℃)抗拉强度,同时塑性也略有提高。Influence of different rare earth amounts on microstructure and mechanical properties of 21-4N steel was studied. Dendrite under the as-cast condition was refined obviously. The extent of segregation and the dimension of inclusions decreased, and the shape of inclusions changed from polygon to ellipse when appropriate amount of mixed rare earth was added. Appropriate rare earth can also reduce the extent of hot rolling texture and improve distribution of carbide in hot rolling state. Room temperature (15 ℃) tensile strength was firstly improved and then appreciably descended. The elongation percentage decreased with the increase of rare earth amount. Appropriate rare earth amount (0%-0. 20%) can improve the high temperature tensile strength and ductility of 21-4N steel.

关 键 词：稀土 21-4N钢 显微组织 力学性能 

分 类 号：TG142.73[一般工业技术—材料科学与工程]