The Similarity Between Inter Granular Cracking of Alloy 600 in Simulated Primary Water and High Purity Hydrogen Gas at High Temperature

Hump-SSRT tests of alloy 600 have been carried out under simulated primary water and dry high purity hydrogen gas at the temperature ranging from 360 to 300 °C. Inter Granular (IG) cracking is observed not only under simulated primary water but also under high purity hydrogen gas. Then hydrogen should be considered as a main factor of PWSCC. The activation energy of PWSCC and IG cracking in hydrogen gas is measured. The relationship between IG cracking susceptibility and surface finish condition of alloy 600 will be discussed.