Development of low-emission next-generation stainless steel E304–16 and E316–16 synthetic electrodes with mild steel Core wire

The demand for cost-effective and environmentally sustainable welding electrodes has increased significantly due to the need for high-performance materials with minimal hazardous emissions. This study focuses on developing novel stainless steel welding electrodes using a flux-modified mild steel core wire. The primary objective is to achieve stainless steel-like mechanical properties while minimizing the release of hazardous emissions such as hexavalent chromium, ozone, and ultraviolet radiation. These newly developed electrodes are designed to provide the strength and corrosion resistance of stainless steel grades 304 and 316 without requiring modifications to conventional manufacturing processes, making them highly suitable for industrial applications, including structural fabrication, automotive components, and marine engineering. A novel flux composition incorporating nano-sized calcium carbonate and calcium titanate was formulated to enhance arc stability, reduce spatter, and improve alloying efficiency. Mechanical testing demonstrated significant improvements in tensile properties, with the ultimate tensile strength increasing to 544 MPa for the stainless steel 304 electrode and 560 MPa for the stainless steel 316 electrode. The yield tensile strength increased to 230 MPa and 285 MPa, respectively, reflecting enhanced resistance to deformation. Bending strength improved to approximately 460 MPa for the stainless steel 304 electrode and 490 MPa for the stainless steel 316 electrode, while microhardness values increased to 240 Vickers hardness number (VHN) and 250 VHN, respectively. Microstructural analysis revealed a refined weld structure with increased acicular ferrite content, leading to enhanced weld integrity and strength. In addition, the optimized flux formulation effectively reduced the release of toxic emissions, with hexavalent chromium concentrations decreasing by 32.7 % for stainless steel 304 electrodes and 22.7 % for stainless steel 316 electrodes. These results demonstrate that the newly developed electrodes provide a balanced combination of mechanical performance and environmental sustainability. The novel approach not only enhances the efficiency of stainless steel welding but also significantly reduces health risks for welders. The findings contribute to the advancement of cleaner welding technologies, offering a cost-effective and sustainable alternative for various industrial applications.