“68牙”齿圈材料和热处理工艺研究

“６８牙”内齿圈是出口的拖拉机行星减速器中的关键零件之一，由于其径向尺寸胀大最大达０．３ｍｍ影响了总成的装配。该齿圈原用２０ＣｒＭｎＴｉ钢制造，用渗碳＋淬火处理。后改用４０Ｃｒ钢制造，最终表面渗氮，制造工艺路线为锻造→正火→粗加工→调质→精加工（钻孔、插齿）→渗氮→装配。作者对该齿圈选材及加工（冷、热加工）工艺流程进行了分析研究，试验了齿圈的正火、调质、渗氮工艺后认为：材料选用和工艺流程没有问题，

Study on Material and the Process of Heat Treatment of the "68-tooth" Ring Gear

The deformation of the "68 - tooth" ring gear after nitriding was beyond tolerance cncerned so that it influence the assemhly of model DW - 3 planctary deceleratr. Itwas found that the process of heat treatment (such as normalizing,quenching, tempering, nitriding and so on)of the part is the main cause.