45钢电解–机械复合抛光工艺优化

Optimization of the process for combined electrochemical and mechanical polishing of 45 steel

采用电解–机械复合抛光工艺处理某压缩机45钢曲轴,以改善其表面粗糙度。通过单因素试验和正交试验对电解–机械复合抛光工艺进行优化,得到的最佳工艺条件如下:对于脉冲电解抛光,输出频率1 000 Hz,方波占空比50%,电解液NaNO3的质量分数20%,电流密度50 A/cm2,工作电压10 V;对于机械抛光,砂轮转速160 r/min,磨削压力2 kg/cm2,砂带粒度号1500#。在最佳电解–机械复合抛光工艺下,45钢的粗糙度Ra均低于0.3μm,比抛光前降低了70%以上,满足粗糙度应低于0.5μm的加工要求。

The crankshaft of a compressor was treated by combined electrochemical and mechanical polishing for improving its roughness. The optimized process conditions by single factor experiment and orthogonal test are as follows： for pulse electropolishing, output frequency 1 000 Hz, duty cycle of square wave 50%, mass fraction of HNO3 in electrolyte 20%, current density 50 A/cm^2, and working voltage 10 V; and for mechanical polishing, rotation rate of abrasive wheel 160 r/min, grinding force 2 kg/cm^2, and granularity of abrasive belt 1500#. Under the optimal process conditions, the roughness （Ra） of polished 45 steel is not higher than 0.3 μm, which is 70% lower than that of the unpolished one, meeting the roughness requirement of less than 0.5 μm.