稀土元素Ce对T15高速钢铸态组织与力学性能的影响  

Influence of Cerium on Microstructure and Mechanical Properties of Cast T15 High Speed Steel

作　　者：屠后田 胡小强[3,4] 杨仁贤 王谦 李殿中 TU Houtian;HU Xiaoqiang;YANG Renxian;WANG Qian;LI Dianzhong(School of Rare Earths,University of Science and Technology of China,Ganzhou 341000,China;Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou 341000,China;Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China)

机构地区：[1]中国科学技术大学稀土学院,赣州341000 [2]中国科学院赣江创新研究院,赣州341000 [3]中国科学院金属研究所沈阳材料科学国家研究中心,沈阳110016 [4]中国科学技术大学材料科学与工程学院,沈阳110016

出　　处：《材料研究学报》2024年第12期932-940,共9页Chinese Journal of Materials Research

基　　金：福建省科技计划STS配套项目(2023T3062);中国科学院赣江创新研究院自主部署项目(E355B0020);中国科学院青年创新促进会优秀会员项目(Y2021060);“兴辽英才计划”青年拔尖人才项目(XLYC2203158)。

摘　　要：采用扫描电镜(SEM)、电子探针(EPMA)、纳米压痕等实验手段,表征了T15高速钢铸态组织中Ce元素的分布,研究了Ce元素对其铸态组织中一次碳化物的作用机制及其对力学性能的影响。结果表明,T15高速钢中的Ce元素主要富集在稀土夹杂物颗粒处,少量的均匀分布在一次碳化物内。添加0.021%(质量分数,下同)的Ce,尽管没有改变T15高速钢铸态组织的类型,但是显著细化了一次碳化物和改善了MC碳化物的塑韧性,从而使其力学性能大幅度提高。与不含Ce元素的T15高速钢相比,添加Ce元素的T15高速钢其铸态组织中一次碳化物的平均等效直径和最大尺寸分别由4.70μm和120.25μm减小到2.91μm和105.39μm;MC中V原子的占比降低了6.16%,形貌由粗大条棒状转变为细密颗粒状,使其塑性因子、断裂韧性提高;T15高速钢硬度、抗弯强度和抗拉强度提高了2.84 HRC、130.52 MPa和59.42 MPa。The effect of Ce addition on the microstructure and Ce distribution characteristics of the as-cast T15 high speed steel(T15 HSS)was investigated by OM,SEM,XRD,EBSD and EPMA.The primary carbides and mechanical properties of the as-cast T15 micro-alloyed without and with Ce were also assessed comparatively by nanoindentation and tensile tests.The results show that the amount of alloyed Ce in T15 HSS enriches mainly in rare earth containing granular inclusions,but a few distributes uniformly in MC primary carbides.The addition of 0.021wt.%Ce does not change the as-cast microstructure types,but it obviously refines the primary carbides,remarkably enhances the plasticity and toughness of MC carbides,and significantly improves the mechanical properties of T15 HSS.Comparing the T15 HSS micro-alloyed with Ce to that without Ce,the average equivalent diameter and maximum size of primary carbides decreased from 4.70μm and 120.25μm to 2.91μm and 105.39μm,with decrement 38.08%and 12.35%,respectively.The amount of V in MC primary carbides decreased by 6.16 at.%,and the morphology of these carbides changed from thick branches into spots.Moreover,the plasticity factor and fracture toughness of MC primary carbides increase from 0.47 and 1.63 MPa·m1/2 to 0.50 and 2.32 MPa·m1/2,respectively.Thus,the hardness,bending strength and tensile strength of as-cast T15 HSS increased from 48.88 HRC,1491.06 MPa and 1122.41 MPa to 51.72 HRC,1621.58 MPa and 1181.83 MPa,respectively.

关 键 词：金属材料 T15高速钢 稀土元素 一次碳化物 铸态组织 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]