中碳微合金钢的断裂韧性与显微组织的关系  

Correlation of Fracture Toughness with Microstructure in MicroalloyedMedium Carbon Steel

作　　者：姚三成 丁毅[3] 赵海 江波[1,2] 刘学华 方政[1,2] YAO Sancheng;DING Yi;ZHAO Hai;JIANG Bo;LIU Xuehua;FANG Zheng(Anhui Province Key Laboratory of High-performance Rail Transportation New Materials and Safety Control,Ma’anshan 243000,China;Technology Center,Ma’anshan Iron&Steel Co.,Ltd.,Ma’anshan 243000,China;Magang(Group)Holding Co.,Ltd.,Ma’anshan 243000,China)

机构地区：[1]高性能轨道交通新材料及安全控制安徽省重点实验室,马鞍山243000 [2]马鞍山钢铁股份有限公司技术中心,马鞍山243000 [3]马钢(集团)控股有限公司,马鞍山243000

出　　处：《材料导报》2020年第S01期452-456,共5页Materials Reports

基　　金：安徽省科技重大专项计划项目(201903a05020052)。

摘　　要：通过断裂韧性与硬度测试,结合定量金相、电子探针(EPMA)、扫描电镜(SEM)、透射电镜(TEM)等,建立了含钒0.10%(质量分数)50Mn钢的断裂韧性与显微组织的关系。结果表明,解理断裂韧性与原奥氏体晶粒尺寸呈负相关关系,晶粒的细化及均匀化能显著提高钢的断裂韧性,可作为重要的控制中碳微合金钢强韧配合关系的组织参量单元。细小均匀的晶粒和未溶的第二相粒子还可使铁素体的形核点增多,从而提高先共析铁素体的体积分数,进一步增大裂纹扩展阻力。The fracture toughness and hardness of 50Mn steel containing 0.10%(mass fraction)vanadium were tested.The microstructure was observed by using the quantitative metallography,electron probe microanalysis(EPMA),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and the correlation of fracture toughness with microstructure was established.The results indicate that cleavage fracture toughness is negatively correlated with prior austenite grain size,the refinement and homogenization of the grains can improve significantly the fracture toughness,which can be used as an important microstructural parameter unit to control the strength and toughness of microalloyed medium carbon steel.The fine and uniform grains and insoluble secondary phases also increase the nucleation sites for ferrite,thus increasing the volume fraction of proeutectoid ferrite,and further enhancing the cracks propagation resistance.

关 键 词：中碳微合金钢 断裂韧性 解理 晶粒尺寸 第二相 

分 类 号：TG142.1[一般工业技术—材料科学与工程]