| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for evaluating degree of sensitization of Cr-containing austenite alloy (hereinafter referred to as an alloy having higher stress corrosion cracking and correlation than those of prior art. SOLUTION: The method for evaluating sensitization of Cr-containing austenite alloy comprises (1) measuring step of repeating an operation for measuring maximum current density flowing to the alloy during a holding time by immersing the alloy in water solution, electrochemically passivating it, then instantaneously changing a potential of the alloy from a passivation potential to a corrosion potential, holding it for a certain time and returning it to the passivation potential by variously varying length of the holding time, (2) a calculating step of obtaining rise starting time for starting to rise the maximum current density from plotting of the density for various holding times, and (3) a judging step of estimating grain boundary Cr concentration from the rise starting point holding time obtained by the calculating step by referring to data indicating the relationship between the previously obtained Cr concentration by using various different alloys having known grain boundary Cr concentration and the rise starting holding time and judging the progress of the degree of sensitization of the alloy when the concentration is reduced. |
