COMPARISON STUDY OF THE EFFECTS OF WELDING CURRENT POLARITY ON WELD PENETRATION AND GEOMETRY USING E6013 AND E6010 COATED ELECTRODE WELDING PROCESSES

Abstract

The coated electrode welding process is highly regarded in the industrial sector due to its versatility and low operating costs. Therefore, it is necessary to understand the influence of each electrode coating type and the effects of current polarity on weld geometry and penetration. This study aims to investigate the influence of current polarity on weld bead geometric parameters using E6010 (Cellulosic) and E6013 (Rutile) coated electrodes in the coated electrode arc welding (SMAW) process. Welds were performed on A36 steel plates under different current conditions: direct current with direct polarity (DCEN), reverse polarity (DCEP), and alternating current (AC). The samples were prepared by metallography, subjected to chemical etching, and characterized by stereoscopy and digital image analysis to measure penetration depth, bead height, and width. The results demonstrated that reverse polarity promotes greater penetration and bead width, especially with the E6010 electrode, demonstrating the higher thermal efficiency associated with heat concentration in the base metal. The E6013 electrode, on the other hand, presented a higher bead height, indicating a lower penetration rate and greater surface accumulation of the weld metal. It is concluded that the appropriate selection of current polarity and coated electrode type significantly influences the heat input, fusion rate, and final geometry of the weld joint, being determining factors for applications with specific penetration and structural integrity requirements.