渗氮过程中轴套开裂原因  

Reasons for cracking of shaft sleeve during nitriding process

作　　者：冯佰刚 裴玉冰[1,2] 王芬玲 巩秀芳[1,2] 范华[1,2] 李清松[1,2] FENG Baigang;PEI Yubing;WANG Fenling;GONG Xiufang;FAN Hua;LI Qingsong(State Key Laboratory of Long Life High Temperature Materials,Dongfang Electric Corporation Dongfang Turbine Co.,Ltd.,Deyang 618000,China;Dongfang Electric Corporation Dongfang Turbine Co.,Ltd.,Deyang 618000,China)

机构地区：[1]东方电气集团东方汽轮机有限公司清洁高效透平动力装备全国重点实验室,德阳618000 [2]东方电气集团东方汽轮机有限公司,德阳618000

出　　处：《理化检验（物理分册）》2024年第7期71-74,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：SKH51高速钢轴套在渗氮过程中发生开裂现象。采用宏观观察、化学成分分析、硬度测试、金相检验、扫描电镜分析等方法分析了轴套开裂的原因。结果表明:轴套基体中的共晶碳化物分布不均匀,在沿轴向方向上存在较为严重的条带状共晶碳化物;材料回火不充分使组织中存在残余奥氏体,在渗氮过程中残余奥氏体转变为马氏体,产生了组织应力;轴套开裂位置处倒角半径过小,产生了应力集中,最终导致轴套发生开裂。The SKH51 high-speed steel shaft sleeve cracked during the nitriding process.The causes of shaft sleeve cracking were analyzed using methods such as macroscopic observation,chemical composition analysis,hardness testing,metallographic examination and scanning electron microscopy analysis.The results show that the distribution of eutectic carbides in the shaft sleeve matrix was uneven,and there were severe strip-shaped eutectic carbides along the axial direction.Insufficient tempering of the material results in the presence of residual austenite in the structure.During the nitriding process,the residual austenite transformed into martensite,resulting in structural stress.The chamfer radius at the crack location of the shaft sleeve was too small,resulting in stress concentration and ultimately led to the cracking of the shaft sleeve.

关 键 词：渗氮过程 SKH51高速钢 开裂 共晶碳化物 组织转变 应力集中 

分 类 号：TG142.45[一般工业技术—材料科学与工程] TB31[金属学及工艺—金属材料]