花键冷滚打和铣削加工的金属组织变形研究

Research on metal microstructure deformation of splines manufactured by cold rolling,milling and cutting processes

本文针对冷滚打花键和铣削花键加工工艺特点,从微观组织分析角度,对两种加工方法得到工件金相组织和硬度分布进行分析比较。试验表明:铣削加工过程中,金属表面组织被切断,内部组织没有发生变化,对力学性能也没有影响;而冷滚打加工后的花键金属组织未被切断,晶粒破碎和细化,位错密度增加,最终被拉成条形纤维组织。相对于铣削,冷滚打加工改善了加工表面金属组织,硬度和强度有较大提高。从而为冷滚打花键成形技术的进一步研究奠定了基础。

On the basis of different technical features of processing spline by cold rolling method and milling method, the microstructure and rigidity distribution of different samples, which were gained from these two processing meth ods, were performed and a comparison analysis from the perspective of microstructure was made. The results show that, in milling method, the surface metal microstructure is cut off. In addition, the mechanical property and internal metal microstructure are not transformed. By contrast, in cold rolling method, the metal microstructure is not cut off, grains are broken and refined, and dislocation density is also increased. Compared with milling method, cold rolling method distinctly increases not only the surface quality, but the hardness and the strength of the metal. The research also lays foundation to the further study of the forming technique of spline.