Alloy 600 is a workhorse alloy in the CPI industry. Technical literature exists that documents that the alloy is prone to sensitization. Recent CPI plant equipment issues were found to be caused by sensitized Alloy 600, which significantly reduced corrosion resistance and resulted in brittle, intergranular failure. The investigation to identify the cause of the sensitization determined that the welding process resulted in overheating the material during a repair. This project will study welding parameters, including systematically varied heat input and Interpass temperature, to characterize the resultant microstructure. The study should also include low- and medium-low carbon content Alloy 600 to better understand welding parameter limitations with small variations in alloy chemistry during fabrication and repair efforts to ensure sound welds for improved equipment reliability.
Metals PDC July 2026