高锰钢精密超精密镜面加工技术及试验研究

Precision and Ultra Precision Mirror Processing Technology and Experiment of High Manganese Steel

目的利用ELID磨削技术对ZGMn13Cr2高锰钢进行精密超精密镜面磨削加工试验研究,解决其加工性能差的问题,以提升表面质量,采用二次回归通用旋转设计试验,探究不同试验因素对ZGMn13Cr2高锰钢加工表面质量的影响规律,并对各因素工艺参数进行优化。方法对MSG-612 CNC超精密成型平面磨床进行ELID磨削工艺模块化改造后,采用240#、W10粒度的金属结合剂金刚石砂轮对直径Φ50 mm、厚度10 mm的样件进行ELID磨削加工,对比两种粒度砂轮的加工效果。应用二次回归通用旋转设计进行工艺试验,搭建表面粗糙度二次回归数学模型,探究不同试验因素对工件表面质量的影响程度,使用判定系数R2检验二次回归模型对实际情况的拟合程度。最后,由lingo软件对二次回归数学模型进行优化,得出ZGMn13Cr2高锰钢ELID磨削各试验因素工艺参数的最佳组合。结果经W10金属结合剂金刚石砂轮加工后,样件获得较高精度的镜面效果,两种粒度所加工的样件表面均无烧伤。判定系数R2检验二次回归模型对实际情况的拟合度为99.24%,模型的预测结果对实际加工有指导意义。优化得出的最佳工艺参数组合为:砂轮线速度35 m/s,电解电压90 V,砂轮进给量2μm,电解间隙0.734 mm。结论ELID精密超精密镜面磨削加工技术可大幅提高ZGMn13Cr2高锰钢的加工效率和加工精度,减少工件表面烧伤,在高锰钢磨削加工方面具有良好的应用价值。

The work aims to study the precision and ultra precision mirror grinding experiment of ZGMn13Cr2 high manganese steel by ELID grinding technology to solve the problem of poor processing performance and to improve its surface quality and then use the quadratic regression universal rotation design test to explore the influence of different test factors on the surface quality of ZGMn13Cr2 high manganese steel,and optimize the process parameters of each factor.The sample with diameter of Φ50 mm and thickness of 10 mm was processed by ELID with metal bonded diamond wheel with grain size of 240# and W10 after the modularization of ELID grinding process for MSG612-CNC ultra precision forming surface grinder to compare the processing effects of two kinds of grinding wheels.The process test was carried out by the universal rotary design of quadratic regression.Then,the mathematical model of quadratic regression of surface roughness was built to explore the influence degree of different test factors on the surface quality of workpiece.Decision coefficient R2 was used to test the fitting degree of quadratic regression model to the actual situation.At last,LINGO software was used to optimize the quadratic regression mathematical model to get the best combination of process parameters of various experimental factors in the ELID grinding of ZGMn13Cr2 high manganese steel.After machining with W10 metal bonded diamond wheel,the sample had a high precision mirror effect,and there was no burn on the surface of the sample processed with two particle sizes.The fitting degree of the quadratic regression model to the actual situation was 99.24%,and the prediction results of the model were instructive to the actual machining.The optimum technological parameters of grinding wheel were obtained,with linear speed of 35 m/s,electrolytic voltage of 90 V,grinding wheel feed of 2μm and electrolytic clearance of 0.734.ELID Precision mirror grinding technology can greatly improve the processing efficiency and accuracy of ZGMn13Cr2 high manganese steel,reduce the surface burn and crack of workpiece,and has good application value in the grinding of high manganese steel.