Analysis of weld characteristics of micro plasma arc welded thin stainless steel 306 L sheet

Abstract

Abstract This work demonstrates joining of thin steel sheet using micro plasma arc welding (MPAW) process. A series of welding experiments are carried out by applying full factorial design of experiment. The process parameters considered are welding current, welding speed and stand-off distance. A sufficient number of trial experiments are conducted to find suitable process window for MPAW of 500 μm thick SS-316 L sheets. Seven weld bead geometry characteristics (viz., area of fusion zone, top bead width, bottom bead width, bead height or penetration, reinforcement, width of left side of heat affected zone (HAZ) and width of right side HAZ), three tensile properties (ultimate tensile strength, yield strength and percentage elongation), micro-hardness and grain size of HAZ are considered as weld quality parameters. Various outlier tests are applied first time in welding for detection of extreme data from the tensile data set. The effects of heat input and process parameters on the measured weld quality parameters are studied. Analysis of variance (ANOVA) is also applied to estimate the relative importance of individual parameter and their interaction on the total variability. Finally, regression models are developed for representing the input and output relationship of the MPAW process.