AN EXPERIMENTAL STUDY OF EFFECT OF WELDING PARAMETERS ON WELD HARDNESS IN MIG WELDING OF SS 304 TAGUHI & RESPONSE SURFACE METHODOLOGY TECHNIQUES OF D.O.E.

Abstract

This study aimed at the investigation of the effect of preheating, shielding gas flow rate and heat input on the hardness of weldment. In this study, 304 stainless steel was bonded by MIG welding with Argon as a shielding gas and hardness properties of the welded samples at different points from the weld centre line was investigated. For that purpose welding was done with different level of preheat, shielding gas flow rate and heat input. Welding samples were characterized by means of hardness test on optical Brinell hardness tester. Hardness test revealed that for all welding parameters hardness in HAZ and weld metal was higher than parent metal. With application of design of experiment (DOE) mathematical relationship between the welding process input parameters and output variable like hardness of welded joint in order to determine the welding input parameters that lead to desired weld hardness. Preheat, shielding gas flow rate, and heat input are selected as input parameter and har...