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As human sharp increase in demand for energy, nuclear power has become an important energy industry, nuclear power plants generally use large castings alloy steel, combined with improved accuracy and surface roughness of the upper and lower half-impermeable sealing engagement of the mating surfaces rough processing after surfacing layer of stainless steel to prevent erosion. And nuclear material Operating humidity, steam turbine last stage exit humidity even more than 20% change in the steam flow direction of the site and there is a combination of surface pressure drop steam leakage gap vulnerable to serious erosion. Pitting and stress corrosion in the joint action of crack propagation, and ultimately the formation of stress corrosion damage. Nuclear materials often lead to the failure of the safety of nuclear power plants, and even affect the safety of people and the environment, endanger the sustainable development of the national economy. Therefore, in order to ensure the quality of the joint surface and prevent erosion and stress corrosion of steel milling surface quality nuclear research is particularly important. In this paper, one million kilowatts of nuclear power units with steel G17CrMoV5-10 and GX4CrNi13-4 two materials for milling tests, analyzes its machined surface integrity test tool selected whirlwind blade coating GC1025 and IC908, mainly from the surface roughness and analyze affected layer. Single factor test and orthogonal test method, select the cutting speed, feed rate, cutting depth and cutting width, the tool nose radius and flank wear and other factors, to the surface roughness (Ra and Rz values) for the trial Target studied machined surface feeding and feed direction perpendicular to the variation of the roughness, the feed and the feed direction perpendicular roughness Rz and Ra value consistent trends. The study materials obtained optimal cutting parameters, GC1025 inserts can get rough smaller degree, Rz value of up to 0.792μm. Right GX4CrNi13-4 material, cutting speed and feed rate on the roughness of the greatest impact. Rε nose radius of 1.2mm, the roughness of the smallest. Meanwhile, the analysis of the heat treatment, the material characteristics of the machined surface. In addition, select the machined surface hardening, microstructure and residual stress characteristics of three changes in indicators of deterioration of the cast steel machined surface layer changes. By changing the cutting speed and feed rate, studied the machined surface modification layer changes, feed 0.1mm / r minimum hardening time, with the feed increases, metamorphic layer first becomes serious, then gradually disappear; depth direction of maximum residue compressive stress value increases. Meanwhile, the analysis of the nose radius and tool wear on the metamorphic layer effects. Tool flank wear a certain value, significant deterioration of the surface layer of tissue. With the nose radius increases, the work hardening becomes serious. The GX4CrNi13-4 materials from the surface 28μm, the maximum compressive stress of up to 432MPa, the maximum depth of the residual compressive stress 100μm. This study received an optimized cutting parameters and tool parameters, to obtain the surface meet the needs of nuclear power quality, increase the reliability of the workpiece, processing efficiency and lower processing costs, and to provide reference for the processing of similar materials.
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