Investigation Analysis of Plasma Arc Cutting Parameters on the Unevenness Surface of Hardox-400 Material

Plasma arc cutting (PAC) is a thermal cutting process that makes use of a constricted jet of high-temperature plasma gas to melt and separate (cut) metal [2]. In this study 12 mm plate thickness Hardox-400 has been cut by high tolerance voltage, cutting speed, and plasma gas flow rate included as main parameters in the analysis and their effect on unevenness of cut surface is evaluated. The design of experiments (DoE) techniques is used in order to outline the main parameters which define the geometry of the cut profile, as well as its constancy for Hardox-400 material plate. Despite the value selected for these parameters, the analysis shows that Hardox-400 plates can have different profiles, depending on the specific side considered. Unevenness can be obtained as a result of an experimental investigation aimed at selecting the proper values of process parameters of PAC system. Results of this screening step are analyzed by means of the Analysis of Variance (ANOVA) technique with use of design expert 8.0.7.1 software in order to clearly identify the main parameters, which define the unevenness quality attribute. The operating conditions have been carefully optimized through parameters adjustment like cutting speed, plasma gas and arc voltage in order to obtain good surface quality for all the sides of Hardox-400 plate.