EXPERIMENTAL ANALYSIS OF WELDING PARAMETERS OF WELDING JOINT OF AUSTENATIC STEEL (300 SERIES) BY TIG WELDING

Abstract

After the advent of welding as a joining method, welding technology was employed as a key joining technique in hi-tech industry for the welding of AISI 321 structures such as pressure vessels and aerospace applications. Due to their high strength and low weight ratio, stainless steel AISI 321 is extensively used for various applications in a number of industries including nuclear, aerospace, chemical, petrochemical, fertilizer, and food processing industries and in many other major industrial operations. Manufacturing industry has taken advantages of tungsten Inter gas (TIG) welding to join structures. High quality weld for stainless steels and non-ferrous alloys are also obtained with this technique. However, in comparison to arc welding processes the TIG welding has lower productivity due to shallow penetration, which confines its application. From industrial point of view, stainless steel AISI 321 is very commonly used material due to its improved corrosion resistance, low weight ratio and better creep rupture strength. In this experimental work, the main objectives are to analyze and optimize the joining of stainless steel AISI 321 sheet by tungsten Inter Gas (TIG) welding using Taguchi experimental design. The current, voltage, gas flow rate and filler rod are the variable parameters in this study. The properties namely ultimate tensile strength (UTS), yield strength, % elongation, joint quality and hardness of stainless steel AISI 321 are investigated by using filler material 316L and 308L at varying current, voltage and gas flow rate.