OPTIMISATION OF PLASMA ARC CUTTING PROCESS OF AISI 304 STAINLESS STEEL USING DESIGN OF EXPERIMENT

Abstract

Owing to its corrosion resistance capability, stainless steel stands out as a material of choice in food processing and other allied industries. However, cutting, during manufacturing activities, poses enormous challenge with regular thermal cutting processes. This study has optimized plasma arc cutting process of AISI 304 stainless steel using a full factorial experimental design. The input process parameters were Cutting Speed (CS), Cutting Current (CC) and Gas Pressure (GP) while the response variables were Material Removal Rate (MRR) and surface roughness. Analysis of Variance (ANOVA) was performed in order to identify the effect of each input process parameters on the response variables. ANOVA revealed that whereas CS made 31.1% contribution to surface roughness of the stainless steel, CC and GP only contributed as much as 31.7% and 28.2% respectively. CC had the most significant effect of 36.07% on MRR followed by GP and CS with 28.02% and 27.11% respectively. While the optimal cutting conditions for surface roughness were found to be 4000 mm/m for CS, 80 A for CC and 6 bar for GP, the optimal values for MRR were 4000 mm/m, 60 A and 6 bar for SC, CC and GP respectively. It can, therefore, be concluded that increase in cutting current favours increased material removal rate during plasma arc cutting processes of AISI 304 stainless steel.