40 Cr 重载车轴断裂失效分析

目的研究车轴在热校直过程中的断裂原因和机制。方法通过对该车轴进行化学分析、金相检测、力学性能检测,对车轴断裂的性质和产生原因进行了分析和讨论。结果准确得出了车轴断裂的性质和产生原因。结论车轴制造工艺不合理,导致车轴轴头产生了严重的过热组织,这是车轴断裂的主要原因;原材料中较多的非金属夹杂物等材质缺陷,造成了材料的综合力学性能降低,尤其是材料的屈服强度降低,是车轴断裂产生的重要原因。建议改进车轴的制造工艺,过热严重的车轴应报废处理。

Fracture Failure Analysis of 40 Cr Heavy Automobile Axle

Objective To find out the causes for crack fault of 40Cr heavy automobile axle. Methods The cracking reason of 40Cr steel was analyzed by means of chemical composition analysis, fracture analysis and microstructure examination. Results The property and cause for the cracking were found with accuracy. Conclusion The results showed that the fracture of 40Cr steel was mainly due to wrong rolling technology, which led to serious overheating parts in the head of the axle. The inclusion of large amounts of non-metallic impurities in the material decreased the comprehensive mechanical property of the material, especially the reduced tensile strength, which was an important cause for the crack of the axle. It is suggested to improve the manufacturing technology of axle and the axles with serious overheating should be discarded.