Influence of Parameters of Gas Metal Arc Welding on Macrostructures and Mechanical Properties of Austenitic Stainless Steels

Abstract:-The Influences of parameters of Gas Metal Arc Welding Process on its microstructures and mechanical properties were investigated in this paper by using Austenitic stainless steel 304 with Factorial Design experiment. The parameters used in this study have Welding current, welding speed, Welding speed, Shielding gas on microstructures, Ultimate tensile strength, Yield strength, Elongation and Hardness. The results of this process revealed that 1) current parameters, welding speed, shielding gas effected on the ultimate tensile strength, yield strength, elongation and hardness by using Welding current about 90Amp, welding speed 500 mm/min and shielding gas of Ar+5%O2, after welding test was found that the ultimate tensile strength values is 940.68 MPa. At welding current about 900A, welding speed 300 mm/min and shielding gas of Ar+3%N2, after welding test was found that the yield strength values is 648.34 MPa. At welding current about 100Amp, welding speed 400 mm/min and shielding gas of Ar+5%H2, after welding test was found that the elongation values are 20 % and at welding current about 90Amp, welding speed 300 mm/min and Shielding gas of Ar+5%H2, after welding test was found that the hardness values is 278.33 HV, respectively. 2) The analysis results of microstructures of the specimens on ultimate tensile strength which are higher and lower strength values were found that microstructures of columnar dendrite and the growth of grains on the heat-affected zone are more differences, that is the area of columnar dendrite is smaller than the specimens on higher ultimate tensile strength and the growth of grains on the heat-affected zone are The chromium carbide (Cr23C6) can be occurred on both of all conditions