某空调压缩机弹簧断裂失效分析

Failure Analysis on Fracture of an Air Conditioning Compressor Spring

某空调压缩机弹簧在系统耐久试验期间发生断裂,采用断口分析、金相检验、化学成分分析、硬度测试等方法对弹簧的断裂原因进行了分析,并对弹簧的疲劳强度进行了校核,对弹簧进行了喷丸工艺改善研究。结果表明:该弹簧实际工作时最大切应力高于材料的许用切应力,在循环载荷作用下安全系数不足,最终发生了疲劳断裂;喷丸工艺可以提高弹簧的可靠性,采用0.2mm钢球喷丸处理后的弹簧表面形貌最优且疲劳寿命最高。

The air condition compressor springs broke during the durability test of the system.Fracture analysis,metallographic examination,chemical composition analysis and hardness test were used to analyze the fracture causes of the springs.The fatigue strength of the springs was checked and the improvement of the shot peening process was also studied.The results show that the maximum shear stress of the springs in practice was higher than the allowable shear stress of the material.The safety factor of the springs was insufficient under cyclic loading,and fatigue fracture finally occurred.The reliability of springs could be improved by shot peening process.The springs treated by shot peening with φ0.2 mm steel balls had the best surface morphology and the highest fatigue life.