Evidence that carbide precipitation produces hydrogen traps in Ni-17Cr-8Fe alloys

The intergranular stress corrosion cracking (SCC) of wrought and welded Ni-Cr-Fe alloys in high-temperature, deaerated water is a concern to the nuclear power industry. While a number of models exist to describe SCC, the physical processes which control cracking are subject to debate. Regardless of the controlling mechanism, grain boundary structure and chemistry play an important role in the susceptibility of Ni-Cr-Fe alloys to intergranular SCC in high temperature water. Grain boundary structure may influence the local chemistry, electrochemistry, and stress state as well as how the embrittling species interacts with the material