The impact of gas pressure and current on the hardness behaviour of Tig welding stainless steel.

The impacts of argon gas pressure and current of the hardness feature of welded joints have been investigated in this paper by employing different ranges of welding gas pressures and currents. The Tungsten Inert Gas welding (TIG) of stainless steel (304) sheet has been applied to get its impact on the hardness feature of the TIG welded joints. Designed of the experiment (DOE) 'version 10' have been used to figure out the design matrix of trials depending on the used levels of the input factors. The rejoinder surface methodology (RSM) method has been adopted to get an empirical mathematical design for the highest hardness feature as a function of factors investigated. Further, the ANOVA method has been done to validate the results of the adequacy model statistically. The outcomes show that the hardness of the welded joints reaches the best level when the current the best current is 80 Amp and the best gas pressure is 13 Kgf/cm2 to give the best value of hardness, however, at a constant gas pressure value of 14 Kgf/cm2, the hardness decreased with the current value increase. Besides statistical results from ANOVA agree with the experimental results with a 0.24% error to identify the best hardness value. [ABSTRACT FROM AUTHOR]