Analysis of Voltage, Current Density, and Welding Speed of Flux Core Arc Welding on the Hardness and Micro-Structure of High Strength Low Alloy (ASTM A572)

This study was carried out to investigate the effect of Flux Core Arc Welding factors on the mechanical properties of High Strength Low Alloy (HSLA). These selected welding parameters were the voltage, current density and welding speed which determined the heat input. The mechanical properties were obtained by performing the hardness test. As for the microstructure changes were observed by metallography test. In the weld metal area, the highest hardness value of 177.8 HV was found in sample with low heat input, followed by high heat input samples of 167.03 HV. From the results, the hardness value is inversely proportional to the heat input. Furthermore, the metallography test gave a result that the hardness has a strong correlation with the ratio of ferrite and pearlite. The higher the hardness, the ratio of ferrite and pearlite was smaller.