Study On Electrochemical Autocatalytic Pretreatment And Machinability Of High Chromium Stainless Steel

With the development of the economy and society,the global demand for energy consumption has shown a significant growth trend.How to solve the energy problem has become an important issue for national development.The content of chromium of the high-chromium stainless steel bearing used in the nuclear main pump is more than 40%.The stainless steel has high hardness and poor thermal conductivity,which is a typical difficult-to-process material.Focusing on the processing problems of the high-chromium stainless steel bearing of the nuclear main pump,this research uses the electrochemical autocatalytic surface pretreatment method to form an oxide layer with a certain thickness on the surface of the high-chromium stainless steel and conduct a processing test.It solves the problems of traditional machinery such as high processing stress,severe tool wear,and poor surface quality.The specific contents studied in this article are as follows:On the basis of systematic analysis of the development status of various electrochemical assisted processing technologies at home and abroad,it is proposed to use electrochemical autocatalytic oxidation method for surface pretreatment and subsequent processing of high chromium stainless steel combined with the processing requirements of high chromium stainless steel in this topic.A three-electrode system is used to compare the electrochemical behavior of high-chromium stainless steel under different electrolyte conditions.Combined with the constant potential polarization experiment and scanning electron microscope microscopic test,and set the current density and the macroscopic and microscopic shape of the anode surface as an indicator,an electrolyte suitable for electrochemical autocatalytic surface pretreatment of high chromium stainless steel is selected,and electrochemical parameters are optimized through single factor experiments.By means of electrochemical analysis and element tracking test,the mechanism of the anode interface reaction of high chromium stainless steel under alkaline conditions is revealed in principle,and the change curve of the thickness of the anodic oxide layer with polarization time under constant potential polarization treatment was measured.The processing parameters of high-chromium stainless steel milling processing are optimized through orthogonal experiments,and the influence of each processing parameter on the milling force is studied through analysis of variance.Two methods of machining based on electrochemical autocatalytic pretreatment and traditional machining are used to conduct comparative experiments.Using surface roughness,milling force,and tool wear as indicators,the machinability of electrochemical autocatalytic pretreatment on high chromium stainless steel materials is analyzed.The results show that the electrochemical autocatalytic surface pretreatment method proposed in this paper can greatly improve the machinability of high chromium stainless steel.