Effect of EN ratio on bead profile and mechanical properties of MC 600 steel in submerged arc welding

Abstract

ABSTRACT In the present work, the effect of electrode negative (EN) ratio on bead cross-section, mechanical properties and microstructure was analysed. The welding was performed on MC-600 steel of 12.5 mm thickness by two passes in butt configuration at three different EN ratios varying from 0.25 to 0.75. Out of different types of power sources, alternating current (AC) with the square wave was selected here for the experiment. Penetration depth and bead width decreased with an increase in EN ratio, but reinforcement height increased with an increase in EN ratio. There is no notable effect on yield strength but ultimate tensile strength increased slightly due to an increase in the EN ratio. Vickers hardness of weld at lowest and highest EN ratios is almost similar and slightly higher than that of the middle one. The impact toughness of all three locations improved with an increase in the EN ratio.