THE EFFECT OF ARGON GAS FLOW AND TIG WELDING CURRENT ON TENSILE STRENGTH OF LOW CARBON STEEL ST37

ABSTRACT
The Tungsten Inert Gas (TIG) welding process uses shielding gas such as argon to prevent oxidation of the metal during welding. This study aims to investigate the effect of argon gas flow rate and welding current on the tensile strength of low- carbon steel ST37, which is widely used in construction and manufacturing due to its good mechanical properties and economic value. TIG welding was chosen for its ability to produce high-quality weld joints. The experiment was conducted by varying argon gas flow rates (5 L/min, 10 L/min, 15 L/min) and welding currents (80 A, 90 A, 100 A) on low-carbon steel ST37. The tensile strength of the weld joints was then measured and analyzed using ANOVA (SPSS) as well as manual calculations. The results show that both argon gas flow rate and welding current significantly affect the tensile strength of ST37 low-carbon steel. The maximum tensile strength of 326.686 N/mm² was achieved at a gas flow rate of 15 L/min and a current of 100 A, while the lowest value of 199.641 N/mm² was obtained at a gas flow rate of 5 L/min and a current of 80 A. Hypothesis testing with an error level (α) of 0.05 indicates that variations in argon gas flow rate and welding current each have an effect on the tensile strength of ST37 low-carbon steel, but their interaction does not significantly influence tensile strength. Thus, increasing argon gas flow rate and welding current tends to improve the tensile strength of TIG-welded joints in ST37 steel.