蜗杆齿面裂纹原因分析及工艺改进

The Reason Analysis and Grinding Improvement of the Worm Tooth Surface Crack

针对蜗杆等齿轮类零件加工中易出现齿面裂纹这一问题,建立了以蜗杆齿面裂纹为顶事件的故障树,对造成该顶事件的故障原因进行逐级分解,从设计硬度、锻件毛坯、热处理、磨削工艺等方面对故障原因进行逐一分解,通过查阅设计标准、锻件毛坯化学分析对设计硬度及锻件毛坯原因进行了排除;分析过程中开展了材料热处理检查和金相组织检测,分析结果显示蜗杆齿面裂纹呈现二次淬火磨削烧伤特征和回火烧伤特征,蜗杆加工过程中磨齿工艺参数不合理,对磨削烧伤开展了故障机理分析,给出了工艺改进措施,最后采用磨削前低温回火消除内应力,调整砂轮转速和进给量等磨削工艺参数解决了蜗杆齿面裂纹问题。对齿轮类零件产生齿面裂纹的原因分析方法与实际问题的解决具有指导意义。

Aiming at the problem that the tooth surface crack is easy to appear in the machining of gear parts such as worm,a fault tree with the worm tooth surface crack as the top event is established.The fault causes of the top event are decomposed step by step,and the fault causes are decomposed from the aspects of design hardness,forging blank,heat treatment,grinding technology,etc.The reasons of design hardness and forging blank are excluded by referring to design standard and chemical analysis of forging blank.In the process of analysis,the material heat treatment inspection and metallography detection are carried out.The analysis results show that the tooth surface crack of worm presented the characteristics of secondary quenching grinding burn and tempering burn.The grinding process parameters are unreasonable in the process of worm machining.Adjusting grinding process parameters such as wheel speed and feed rate solve the problem of worm tooth surface crack.It is instructive to analyze the causes of tooth surface cracks in gear parts and solve practical problems.