Stress corrosion behaviour of nickel superalloy weldments

Alloys 690 and 600 were welded to type 304L stainless steel using Inconel 82 as a filler. The investigation involved evaluation of the weldment's resistance to stress corrosion cracking (SCC). Results of slow strain rate testing in a simulated pressurised water reactor environment showed that alloy 600 is more susceptible to SCC than alloy 690. However, both nickel alloys have superior resistance to SCC compared with type 304L stainless steel. The Inconel 82 weld metal developed an extremely dense oxidation layer which could not be removed by a stainless steel brush and may require use of a grinder to ensure a sound weld.