| Popis: |
Stainless steel components are often joined by welding when fabricated into structures. Fusion welding of these steels results in the formation of carcinogenic Cr(VI) in the weld fumes as a result of the Cr content of the commonly used filler metals. This is a significant health hazard for the welders and necessitates protective gear or expensive ventilation systems to meet the stringent Permissible Exposure Limit for chromate set by OSHA. This project developed a Cr-free consumable for welding 304 austenitic stainless steel that provides mechanical properties and corrosion resistance comparable to the commonly used Cr-bearing consumables. A weld wire of composition Ni-7.5Cu-1Ru-0.5Ti worked well in gas metal arc and gas tungsten arc welding operations. For shielded metal arc welding, coated electrodes with cores wires of composition Ni-7.5Cu-4Ti-1Ru performed well. The performance characteristics of these welds were excellent, including mechanical properties and corrosion resistance. Essentially no Cr was detected in the weld fume. |
