Roughness Analysis on Concave Surface for Martensitic Steel AISI 420 Obtained in the 3D Machining Process

The objective of this project is to study the surface roughness and the percentage influence of the factors involved in a machining process on a convex surface on the AISI 420 steel, using a variety of parameters on cutting speed, tool feed and machining strategy. These parameters were applied on a software CAD-CAM to generate the different machining strategies, resulting in 27 test which were carried out on a CNC machine. Once the machining process was completed, the Taguchi methodology and ANOVA statistical analysis were applied to analyze the roughness obtained on the surface under study, showing that the machining strategy has an influence on the roughness value of 78.931%, followed by the cutting speed with 9.812% and finally the tool feed with 0.981%. In addition, this analysis indicates that the optimum machining parameters for this type of surface on the AISI 420 are the use of a Radial Zigzag strategy with a cutting speed of 100 m/min and a tool feed of 0.15 mm/tooth. It should be mentioned that by applying the ANOVA statistical analysis, it was possible to obtain an equation that allows to predict the average value of roughness on this surface. Showing that it can predict the values with an error of less than 20% with respect to the values obtained experimentally, thus allowing validation of the equation for its use.