Ce对30MnNbRE钢淬火回火微观组织和力学性能的影响  

Effect of Ce on microstructure and mechanical properties of 30MnNbRE steel after quenching and tempering

作　　者：宋操 王晓东[1] 包喜荣[1] 陈林[1] 汤雪娇 Song Cao;Wang Xiaodong;Bao Xirong;Chen Lin;Tang Xuejiao(School of Materials and Metallurgy,Inner Mongolia University of Science&Technology,Baotou Inner Mongolia 014010,China)

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

出　　处：《金属热处理》2023年第9期143-149,共7页Heat Treatment of Metals

基　　金：国家自然科学基金(52164046)。

摘　　要：采用扫描电镜、X射线衍射仪、硬度测试、拉伸试验、冲击试验等研究了稀土元素Ce对30MnNbRE钢淬、回火后微观组织及力学性能的影响规律。结果表明,Ce促进Nb在γ-Fe中固溶,增加淬火后的硬度,而回火时Ce促进纳米级(FeMnNb)_(3)C析出,尺寸约为40 nm,产生显著的析出强化作用,同时在马氏体板条间析出的(FeMnNb)_(3)C对位错的钉扎作用可细化板条厚度,最终获得均匀细化的纳米级马氏体板条结构。当Ce添加量为0.01%时,30MnNbRE钢的各项力学性能最佳,450℃回火后硬度可达42.6 HRC,抗拉强度提高至1135 MPa,同时获得尺寸约1μm的细小球状夹杂物,断后伸长率最高可达13.8%,断口呈现韧性断裂特征。Effect of rare earth element Ce on microstructure and mechanical properties of 30MnNbRE steel after quenching and tempering were studied by means of scanning electron microscope,X-ray diffractometer,hardness test,tensile test and impact test.The results show that Ce promotes the solution of Nb in γ-Fe and increases the hardness after quenching,while Ce promotes the precipitation of nanoscale(FeMnNb)_(3C) with a size of about 40 nm during tempering,resulting in a significant precipitation strengthening effect.At the same time,the pinning effect of(FeMnNb)_(3C) precipitated between laths refines the thickness of the martensite laths,and finally obtain a uniform and refined nanoscale martensite lath structure.When the addition amount of Ce is 0.01%,the mechanical properties of the 30MnNbRE steel are the best.After tempering at 450 ℃,the hardness can reach 42.6 HRC,the tensile strength increases to 1135 MPa,the fine spherical inclusions with a size of about 1 μm are obtained,concurrently the elongation after fracture is the largest which reaches 13.8%,and the fracture shows ductile fracture characteristics.

关 键 词：CE 淬火回火 微观组织 力学性能 析出 稀土夹杂物 

分 类 号：TG335[金属学及工艺—金属压力加工]