Experimental investigation of cut quality characteristics on SS321 using plasma arc cutting

This work investigates the cut quality characteristics of SS321 using plasma arc cutting. The SS321 has a wide range of applications such as in chemical storage, exhaust manifolds of automotives and aircraft. The intricate shapes for this material are very difficult to cut using conventional machining process. Hence, plasma arc cutting is used. The input cutting parameters are cutting speed, current, stand off distance and gas pressure. For each input parameter, three levels are considered and, therefore, total numbers of experimental runs are 3 × 3 × 3 × 3 = 81. To minimize the number of runs, the Taguchi L9 orthogonal array is proposed which is having advantages of both minimum and maximum trial runs. The output parameters are surface roughness, kerf width and heat-affected zone. The experiments are carried out in Micro Step spol S.R.O. Plasma arc cutting machine. To find the best cutting parameters, the regression models are given as input of Matlab-Genetic Algorithm. The test results show that ANOVA models are significant. It is inferred that lower values of current and Standoff Distance give better surface roughness and minimum heat-affected zone.