Investigation and optimization of surface roughness with experimental design methods by turning of AISI-1050 after spheroidization heat treatment

In this study, surface roughness values that were obtained by turning a medium-carbon steel (AISI 1050) applied to spheroidization heat treatment were modeled with two different optimization methods. The test materials were subjected to spheroidization heat treatment for three different periods as 15, 60, and 180 min. Three different cutting speeds and three different feed rates were used for the turning operations. Surface roughness values obtained from the surface of the workpieces after turning were analyzed by the response surface method (RSM) and Taguchi method (TM). These analyses show that the surface roughness changes directly depending on the feed rate and other parameters have a limited effect on the surface roughness. The regression analysis revealed that in both methods, the R-2 values were higher than 0.99, and it showed the effectiveness of these two methods. As a result, these two different experimental design methods showed high stability in solving this engineering problem. Additionally, in the comparison of the methods with each other, the ratio of similarity to the experimental results was evaluated by considering the percentage. The ratio of similarity was obtained by over 90% in both methods. When the ratio of similarity was analyzed, RSM had more effective results than TM.