EFFECT OF WELDING PARAMETERS ON MECHANICAL AND MICROSTRUCTURAL PROPERTIES OF COLD METAL TRANSFER-WELDED THIN SHEET AISI 301LN STAINLESS STEEL

Joining thin plates is a significant challenge in manufacturing, demanding precise control to produce high-strength, spatter-free welds. Cold metal transfer (CMT) welding, known for its minimal heat input, is a promising solution for this challenge. This study looks into the welding of AISI 301LN stainless steel thin sheets using the CMT technique, specifically the influence of important parameters such as welding current (I), welding speed (S), and contact-tip-to-workpiece distance (CTWD). Fractographic investigation using FESEM revealed characteristic dimpled and crack-free tensile fracture surfaces, indicating high mechanical integrity. Among the parameters, welding speed (S) had a highly influential impact on tensile strength, followed by welding current (I) and contact-tip-to-workpiece distance (CTWD). Ideal welding conditions include a current of 100 A, a speed of 4 mm/sec, and a CTWD of 7 mm, producing welds with exceptional mechanical characteristics, complete penetration and a significant, 24.10 % increase in tensile strength. A drop in the microhardness of the weld zone is observed due to the formation of dendrites.