赤峰热电厂细碎机轴断裂原因分析

Fracture Analysis of the Thermal Power Plant Crusher Shaft

利用金相检验、化学成分分析和力学性能测试等实验手段，对40CrNiMo钢细碎机轴在使用过程中发生断裂的原因进行了分析。结果表明：细碎机轴有一个封闭起来的原始键槽，存在尖角、空隙及异种钢结合面．造成严重应力集中。在长期交变裁荷的作用下，在异种钢界面的尖角处萌生裂纹，最终导致细碎机轴疲劳断裂。

Fracture analysis of the 40CrNiMo steel crusher shaft was carried out using metallographic examination, chemi- cal composition analysis and mechanical test. The results showed that the crusher shaft had an enclosed original keyway with sharp corners, voids and different steel interface resulting in severe stress concentration. Under the alternating load for a long time, cracks formed in sharp corners with different steel interface, eventually leading to the crusher shaft fatigue fracture.