A New Chromium-Free Welding Consumable for Joining Austenitic Stainless Steels

Federal legislation was enacted in 2006 reducing the permissible exposure limit (PEL) of workers, including welding-related personnel, to Cr(VI) by an order of magnitude. Achieving the new level may not always be practical during fabrication or repair of stainless components in tightly enclosed locations. Therefore, the current study was performed to evaluate the use of Ni-Cu-based welding consumables to weld Type 304L. stainless steel while achieving significant reductions of Cr(VI) bearing compounds in welding fume. Consumables were made in bare wire form for gas tungsten arc welding (GTAW) and in coated form for shielded metal arc welding (SMAW). During the development of these consumables, several generations were produced with each improving on the previous generation. Weldability was a primary focus during the development process because switching from a stainless steel welding consumable to a Ni-based alloy could potentially exacerbate weldability issues such as solidification, liquation, and ductility dip cracking. Welds were deposited on Type 304L base metal with the consumables developed during the study and subjected to various tests to evaluate mechanical and corrosion behavior, resistance to weld cracking issues typical of Ni-based alloys, and fume generation characteristics. Weld mechanical properties and weldability performance were similar in nature to other austenitic Ni-based alloys and stainless steels. By using the Ni-Cu based consumable to weld stainless steel, Cr(VI) in the welding fume was reduced by two orders of magnitude from conventional stainless steel welding electrodes.