Investigation of the effect of cold metal transfer welding on fracture toughness of stainless steel 304 L

This paper investigates the Mode-I fracture toughness of stainless steel 304 L specimens produced using Cold Metal Transfer (CMT) welding technology, comparing their performance to industrial-grade and heat-treated (HT) stainless steel. Compact Test (CT) specimens were fabricated using CMT Cyclic and CMT Dynamic processes, and tested per ASTM E-399 standards. Fracture surface analysis was conducted with Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), revealing differences in fracture behavior between CMT, HT stainless steel. Additionally, Finite Element Analysis (FEA) was used to simulate stress distribution and fracture patterns in the CT specimens. Stainless steel 304 L, known for its corrosion resistance and mechanical properties, was selected for its relevance to marine and industrial applications. The study offers a detailed comparison of fracture toughness and fracture surface morphology, highlighting the effects of welding and heat treatment processes. Experimental results of CMT demonstrate a 17 % improvement in fracture toughness compared to SS304L. CMT welds exhibited a fracture toughness (Kq) of 61.41 MPa√m, indicating a 17 % improvement over conventional SS304L (Kq = 52.73 MPa√m) and a slightly higher value than HT SS304L (Kq = 53.54 MPa√m). Results suggest that CMT welding can be a viable method for producing high-performance stainless steel components in demanding environments. • CMT-welded 304L stainless steel showed 17 % higher Mode-I toughness than conventional and heat-treated welds. • CMT specimens showed unique fracture behavior and improved properties based on ASTM E-399, SEM, EDS, and FEA analyses. • CMT stainless steel shows higher strength and reliability, making it suitable for demanding marine and industrial uses. • CMT, as an advanced additive process, shows strong potential to boost material performance and raise industrial standards.