Stress corrosion cracking of fusion boundary for 316L/52M dissimilar metal weld joints in borated and lithiated high temperature water

The stress corrosion cracking (SCC) crack growth rates (CGRs) at the fusion boundary (FB) for 316L/52M weld joints were measured using direct current potential drop systems in borated and lithiated high temperature water. The cracks propagated along the FB and were blocked after propagating into the composition transient zone. The cracking mode is both intergranular and transgranular. The CGRs at the FB are similar to those in the heat-affected zone (HAZ) in oxygenated water, but slightly higher than those in the HAZ in hydrogenated water. The temperature dependences of CGR in both hydrogenated and oxygenated water are discussed.