齿轮磨齿裂纹的产生及控制

Forming and Controlling of Cracks in Gear Grinding

对高精度齿轮，磨齿加工是保证精度和质量的主要加工方法，由磨齿裂纹引起齿轮报废是加工中常出现的现象。对渗碳淬火齿轮的磨齿加工控制不好，废品率高达30－40％，一般也有3－5％。本文研究磨齿裂纹的形态特征及引起磨齿裂纹的冷热加工因素，提出齿轮渗碳时把表面碳浓度从0．8－0．9％提高到1．0－1．2％，渗碳后采用650℃二次高温回火。在磨齿工序中，采用控制磨齿工艺参数、冷却介质和工作环境温度等措施，使废品率降至0．5－1％。

For high precision gears,gear grinding is a principal way of machining to guarantee precision and quality,Gear rejects caused by cracks in gear grinding are common in gear machining. In grinding of carburized and quenched gears,the reject rate is generally 3~5%, and even as high as 30~ 40% if machining processes are not controlled appropriately. The paper studies the characteristics of the crack patterns in gear grinding as well as the factors of cold and hot working that could lead to the forming of cracks. Proposals are made to increase the surface carbon concentration from 0. 8~0. 9% to 1.0~1. 2 % in gear carburization, followed by high temperature retempering at 650℃. In the grinding process, controlling of grinding parameters, cooling media and ambient temperatures are adopted, which results in a decrease inreject rate to 0. 5~1 %.