晶粒尺寸与碳化物组织细化对18Cr14Co12Mo4轴承钢性能的影响  

Influence of grain size and carbide structure refinement on properties of 18Cr14Co12Mo4 bearing steel

作　　者：肖桂枝[1] 李鹤 庞玉华[1] 孔浩然 刘东[2] Xiao Guizhi;Li He;Pang Yuhua;Kong Haoran;Liu Dong(School of Metallurgy,Xi'an University of Architecture and Technology,Xi'an 710055,China;School of Materials,Northwest Polytechnical University,Xi'an 710072,China)

机构地区：[1]西安建筑科技大学冶金学院,陕西西安710055 [2]西北工业大学材料学院,陕西西安710072

出　　处：《锻压技术》2024年第10期1-7,共7页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51804241)。

摘　　要：18Cr14Co12Mo4轴承钢在高温扩散热处理后,粗大组织未彻底消除,且晶粒尺寸异常粗大,导致材料力学性能降低。针对该问题,对高温扩散热处理后的18Cr14Co12Mo4轴承钢进行锻造比为2.0~2.2的两镦两拔试验,通过场发射扫描电子显微镜对材料微观性能进行表征,并对比分析了锻造前后晶粒大小和组织结构对力学性能的影响。结果表明:该试验细化了晶粒尺寸,平均晶粒尺寸达到30μm,且减小了微米级碳化物和氧化物的尺寸,减轻了由于合金成分分布不均引起的碳化物偏析,使屈服强度由272 MPa提升至340 MPa,抗拉强度由381 MPa大幅度提升至1637 MPa,提高约4.3倍,伸长率由13.5%提升至24.2%,晶粒尺寸和碳化物组织的细化使18Cr14Co12Mo4轴承钢的力学性能大幅度提升。After high-temperature diffusion heat treatment,the coarse structure of 18Cr14Co12Mo4 bearing steel is not completely eliminated,and the grain size is abnormally coarse,which decreases the mechanical properties of material.For the problem,the test of two upsetting and two drawing was conducted on 18Cr14Co12Mo4 bearing steel after high-temperature diffusion heat treatment with a forging ratio of 2.0-2.2,and its microscopic properties were characterized by field emission scanning electron microscopy.Then,the influences of grain size and microstructure on the mechanical properties before and after forging were compared and analyzed.The results show that the test refines the grain size to make the average grain size be 30 μm,decreases the size of micro scale carbide and oxide,alleviates the carbide segregation caused by the uneven distribution of alloy components,increases the yield strength from 272 MPa to 340 MPa,greatly enhances the tensile strength from 381 MPa to 1637 MPa with an increasing of about 4.3 times,and improves the elongation from 13.5% to 24.2%.The refinement of grain size and carbide structure notably enhance the mechanical properties of 18Cr14Co12Mo4 bearing steel.

关 键 词：轴承钢 两镦两拔 锻造比 高温扩散 晶粒尺寸 碳化物偏析 

分 类 号：TG316[金属学及工艺—金属压力加工]