Keywords: Varestraint test, austenitic stainless steel, weld metal, hot cracking, weldability assessment, welding electrodes, nitrogen, shielded metal arc welding, SMAW, ferrite content
The weldability assessment of modified E316-15 stainless steel welding electrodes
Nitrogen-added Shielded Metal Arc Welding (SMAW) electrodes of a modified E316-15 austenitic stainless steel have been developed for the welding of 316L(N) stainless steel structural components for service at 673°K?823°K. The specifications for these welding electrodes include several modifications of the AWS/ASME SFA 5.4 specifications, including the chemical composition, ferrite content and mechanical properties. The delta-ferrite content in the weld metal has been specified in the range of 3-7 FN. The minimum ferrite content is specified to ensure crack-free welds during fabrication, while the maximum ferrite content is restricted for limiting the formation of embrittling secondary phases during high-temperature service. The weldability of these modified E316-15 electrodes, with stringent control of the chemical composition and ferrite content, has been evaluated using Varestraint tests.