The use of an overalloyed filler is suggested to maintain corrosion resistance in the as-welded condition. Filler metals containing at least 6% molybdenum are suggested for welding Alloy 317L and a filler metal with at least 8% molybdenum, such as Alloy 625, is suggested for 317LMN. In applications where it is not possible to use an overalloyed filler metal or to perform a post-weld anneal and pickle treatment, the severity of the service environment should be carefully considered to determine if the properties of autogenous welds (weld made without a filler) are satisfactory. The optimum corrosion resistance of autogenously welded 317LMN and Alloy 317L stainless steel pipe is obtained by post-weld annealing and pickling. ASTM A380 "Recommended Practice for Descaling and Cleaning Steel Surfaces" is suggested for more information.
