Study On The Surface Roughness Of 45 Steel Turning Based On Orthogonal Test

The surface roughness is one of the important indexes to measure the surface quality of machining at present,mainly to choose the appropriate tool and the corresponding turning process parameters to control the turning surface roughness on the turning experiment and experience,with uncertainty and considerable limitations.In this paper,the influence of turning tool and cutting parameters on the surface roughness is studied by the turning experiment of 45 steel hardened steel.The main research contents are as follows:With cemented carbide and ceramic tool of hardened 45 steel specimens using the single factor cutting experiment of cutting speed and feed rate F,back cutting depth and tool radius and other parameters for the workpiece surface roughness are investigated.The experimental results show that the use of hard alloy and ceramic tool were tested in dry machining parts,the specimen surface roughness increases with the amount of feed;with ceramic cutting tool,surface roughness of specimen with increasing cutting speed decreases,but the variation is small;turning with carbide tool when the surface roughness of specimen increases as the radius decreases;with ceramic cutting tool,tool radius is 0.8 mm when the specimen surface roughness minimum.According to the experiment results of the single factor design and three factors?cutting speed,feed rate and cutting depth of F AP?five level orthogonal cutting experiment and the experimental results of the range analysis and variance analysis of turning variables for influence of turning surface roughness.The analysis results show that the carbide tool machining,cutting depth on surface roughness is more obvious,with the increase of cutting depth,surface roughness in accordance with certain trends gradually increased;influence trend of feed back engagement with the overall trend of a cause,but the slope of the curve was significantly more than the effect of depth the curve slope is large,the amount of feed for the effect of surface roughness is backcutting depth significantly;the surface roughness increased with the increase of cutting speed firstly decreased and then increased,the overall change is not obvious,compared to the impact of the amount of feed and cutting depth,cutting speed has little effect.By using regression analysis method to establish the empirical formula for surface roughness of cutting parameters and according to orthogonal test results?polynomial linear regression equation?R_a=31.3521 a_p^-0.22954 f^-0.0719,for the future of hardened 45 steel turning provides the basis to choose the parameter.Finally,the surface roughness model was optimized by using DPS,F,on the feed cutting speed and cutting depth of AP on the influence of surface roughness,optimum cutting parameters,provides a theoretical basis for production practice.