摘要
采用火花直读光谱仪、能谱分析仪、金相显微镜和洛氏硬度计等分析设备,观察和检测了H13钢模芯失效件的化学成分、金相组织及硬度等,分析了H13钢模芯开裂的原因。结果表明,由于模芯原材料前期冶炼不当,存在较严重的成分偏析,生成了液析碳化物;模芯在后期的热处理过程中,回火温度不够,形成晶粒粗大的回火马氏体组织和沿晶碳化物,从而造成模芯脆性显著增强,芯部硬度达到57.2 HRC,远高于正常回火组织要求的47~49 HRC。模芯根部过渡圆弧并不光滑,导致宏观裂纹最先从该部位产生,然后裂纹快速扩展,直至断裂。
By means of spark direct reading spectrometer,energy spectrum analyzer,metallographic microscope and rockwell hardness tester,the chemical composition,microstructure and hardness of the failure parts of H13 steel die core were observed and detected,and the reason of the cracking of H13 steel die core was analyzed.The results show that due to the improper smelting of the core material in the early stage,there is a serious component segregation,resulting in the formation of liquid carbide;In the later heat treatment process,the tempering temperature of the die core is not enough to form coarse-grained tempering martensite structure and intercrystalline carbide,resulting in significantly increased brittleness of the die core,and the hardness of the core reaches 57.2 HRC,which is much higher than 47~49 HRC required by normal tempering structure.The transition arc at the root of the die core is not smooth,which leads to the macroscopic crack first generated from this part,and then the crack expands rapidly until the fracture.
作者
吉国强
蔡榕
葛贵明
罗芷琪
林颖菲
JI Guoqiang;CAI Rong;GE Guiming;LUO Zhiqi;LIN Yingfei(Guangdong Institute of Analysis(China National Analytical Center,Guangzhou),Guangdong Academy of Sciences,Guangzhou 510070,China;Shaoguan NACC Collaborative Innovation Technology Co.,Ltd.,Shaoguan 512026,China;Guangdong Institute of Materials and Processing,Guangdong Academy of Sciences,Guangzhou 510650,China)
出处
《铸造技术》
CAS
2020年第6期553-556,共4页
Foundry Technology
基金
广东省省级科技计划项目(2016B020211004)。
关键词
H13钢
模芯
液析碳化物
元素偏析
疲劳断裂
H13 steel
die Inset
liquation carbide
segregation of elements
fatigue fracture
