摘要
某摩托车发动机平衡轴材料为20CrMo钢,经过渗碳、淬火、冷处理和低温回火处理,仅运行了5 h就断裂。对断裂的平衡轴进行了宏观检验、断口分析、化学成分分析、金相检验和硬度测试。结果表明:平衡轴的化学成分、硬度、有效硬化层深度和显微组织均符合技术要求,裂纹源起源于平衡轴的销孔,平衡轴是在交变应力的作用下因过载而断裂的。
A motorcycle balance shaft,which was made from 20 CrMo steel and carburized,hardened,cold treated and low-temperature tempered,broke after running for as little as 5 h.The macro-check,fracture testing,chemical composition analysis,metallographic examination,and hardness measurements were accomplished for the broken balance shaft.The results showed that the chemical composition,hardness,effective hardening depth of the balance shaft all conformed with the technical requirements,crack originated from pin hole of the balancing shaft,and the balancing shaft broke due to overloading under the action of alternating stress.
作者
张绘
ZHANG Hui(FAW Wuxi Oil Pump and Nzzloe Research Institute,Wuxi 214063,Jiangsu China)
出处
《热处理》
CAS
2022年第3期37-39,共3页
Heat Treatment
关键词
平衡轴
销孔
过载断裂
balance shaft
pin hole
overloading fracture
