Mechanical Properties and Microstructural Analysis of 304 Stainless Steel by TIG Welding

Abstract

Gas tungsten arc welding is the process repairing and widely used in heavy engineering for joining metal. It can be uses for various type of metal and application. The aim of this project is to study the effects of 304 stainless steel with 3 mm thickness on mechanical properties and its microstructure analysis towards gas tungsten arc welding method. The variables set up in this project were current, gas flow rate and welding direction upon rolling direction of stainless steel sheet. Three current setup were used which is 60 A, 80 A and 100 A Type of filler metal used in this project was ER 308L with 1.6 diameter. Two set up for gas flow rate were used which is 8 l/m and 12 l/m. Testing that carried out were tensile test, Vickers macro hardness test with 10 kgf load and microstructure analysis by using optical microscope. The effects of microstructure in austenitic stainless steel welds is discussed. From the mechanical properties procedures, the strength of the weld metal was obtain. For hardness testing, the most important zone to be focused were heat-affected zone (HAZ) and weld metal (WM). The integrity of the welding tested by using tensile test and hardness test with different amount of current and gas flow rate.