在齿轮生产中,常有切渗碳淬火齿轮内孔键槽或花键槽的情况,这种齿轮(图1)在渗碳时,内孔同时渗碳经整体淬火后其硬度一般稍低于齿面硬度(齿面硬度HRC58～63)。而键槽插刀或拉刀为高速钢W18Cr4V,硬度为HRC62～70,实际切削时硬度只达到HRC55～60,所以不可能完成加工,采用线切割成本甚高。为此,我们采用以下方法,解决了实际问题。车渗碳层方法由于一般齿轮的渗碳层深度为0.6～1.2mm,再加上渗碳区域的过渡区(约0.3～0.5mm)所以,在渗碳前精加工时,齿轮内孔及孔口两端面各留1.5～2mm余量。若孔口端面留量 In the production of gears, often cut carburizing quenching gear bore keyway or spline groove, this gear (Figure 1) in the carburizing, the hole while carburizing the overall hardness after quenching generally slightly lower than the tooth surface Hardness (tooth surface hardness HRC58 ~ 63). The key slot knife or broach for the high-speed steel W18Cr4V, hardness HRC62 ~ 70, the actual hardness of only HRC55 ~ 60, it is impossible to complete the processing, the use of wire cutting cost is very high. To this end, we use the following method to solve the practical problems. Car carburizing method As the general carburizing gear depth of 0.6 ~ 1.2mm, together with the carburizing zone transition zone (about 0.3 ~ 0.5mm) Therefore, before carburizing finishing, the gear bore and hole Mouth left and right sides remain 1.5 ~ 2mm margin. If the orifice face to keep