The Relationship Between Cathodic Current in Rapid Straining Electrode Test and PWSCC Crack Growth Rate of Nickel Based Alloys Under Simulated Primary Water Condition

Rapid straining electrode test of nickel based alloys has been carried out under simulated primary water with and without dissolved hydrogen (DH). Very rapid and relatively slow repassivation of TT690 and alloy 600 is observed under the condition without DH respectively, however repassivation could not be observed and only cathodic current is observed under the condition with DH. Cathodic current of 690 is about 1/5 of alloy 600 and 132. The relationship between these cathodic current and PWSCC behavior of these materials will be discussed.