高速冷滚打成形花键表面加工硬化试验

以渐开线花键为研究对象,进行了高速冷滚打成形工件的显微硬度和扫描电镜试验,分析了同一工艺参数下花键不同位置表层硬度随深度的变化趋势,花键的表面硬化程度和微观组织随不同工艺参数的变化规律。试验结果表明:同一工艺参数下,齿顶、分度圆和齿根的表层硬度均随着与齿面距离的增大总体趋于减小,基体硬度为238.5 HV,花键表面形成明显的加工硬化层,齿顶处表面硬度值最小,且硬化层最浅;齿根部分表面硬度略低于分度圆处的表面硬度,硬化层达到1.5 mm;成形花键的表面加工硬化程度,在同一转速下,随着进给量的增大而上升,在同一进给量下,随着转速的增大而下降。

Experiment on surface work-hardening of spline by high speed cold roll-beating

For the involute spline,the microhardness and scanning electron microscope experiments of workpiece processed by high speed cold roll-beating were carried out.It was analyzed the variation trends of spline surface hardness in different positions with different depths with the same process parameter and the changes of spline surface hardening degree and microstructure with different process parameters.The experiment results show that the surface hardness of addendum,pitch and dedendum tends to reduce with the increase of distance from the tooth surface with different process parameters.The matrix hardness of workpiece is 238.5 HV,and the spline surface forms work-hardening layer.In the addendum,the hardness is the smallest,and the hardening layer is the shallowest.In the dedendum,the hardness is lower than that of the pitch,the harden layer is up to 1.5 mm.The spline surface hardening degree increases with the increase of feed rate at the same rotation speed,and decreases with the increase of rotation speed at the same feed rate.