摘要
通过宏观检验、化学成分分析、硬度测试、金相检验和SEM形貌分析等方法对机加工刀具用W6Mo5Cr4V2钢开裂原因进行了分析。结果表明,失效机加工刀具组织存在断续网状与堆集的多角状碳化物以及后续热处理工艺不当导致的刀具出现未淬透现象是造成刀具开裂的主要原因。刀具淬硬区与未淬硬区之间的过渡区域及芯部网状与堆集的多角状碳化物集中处会产生较大应力集中点,在刀具进行磨削加工工艺或操作不当时,表层拉应力超过材料强度极限,并在内部淬火应力作用下,在应力点产生裂纹并扩展,最终导致刀具崩裂。
The cracking causes of W6Mo5Cr4V2 steel used in machining tools were analyzed through macroscopic inspection,chemical composition analysis,hardness testing,metallographic examination and SEM morphology analysis,etc.The results showed that the main cause of tool cracking was that the failed machining tools exhibited the microstructure with discontinuous reticular and aggregated polyhedral carbides,as well as inadequate quenching due to improper subsequent heat treatment processes.The transition zone between the hardened and unhardened regions,as well as the concentration areas of reticular and aggregated polyhedral carbides in the core region,generated large stress concentration.During grinding process or improper operations,the tensile stress on the surface exceeded the tensile ultimate strength of the material,and under the influence of internal quenching stresses,cracks was initiation and propagation,ultimately leading to tool breakage.
作者
韩克甲
王彤
孟林
丁铄锟
HAN Kejia;WANG Tong;MENG Lin;DING Shuokun(National Pump Product Quality Inspection and Testing Center,Zibo 255063,Shandong,China;Zibo Product Quality Inspection Research Institute,Zibo 255063,Shandong,China)
出处
《热处理技术与装备》
2024年第2期34-36,40,共4页
Heat Treatment Technology and Equipment
基金
国家市场监督管理总局科技计划项目项目(2021MK060)。
