A nondestructive method for detection and evaluation of degradation of 2.25Cr-1Mo steel by means of an electrochemical technique is described. A degree of materials degradation can be evaluated by the peak value of current density (△Ip) obtained by anodic polarization measurement. △Ip corresponds to the rate of selective dissolution of coarse carbides M6C. △Ip shows a good correlation with △FATT. Hence, toughness reduction can be nondestructively estimated by △Ip measurements. △Ip can be a representative parameter showing the decrease in solute Mo concentration in the matrix because of M6C (Mo-rich) carbide coarsening. △Ip shows a good correlation with hardness change △Hv. Based on this correlation between △Ip and △Hv, the degree of softening can be nondestructively estimated. The L.M.P. value of materials used in actual plants can be estimated by △Ip measurements.
|Number of pages||6|
|Journal||Mechanical and corrosion properties. Series A, Key engineering materials|
|Publication status||Published - 1991|
|Event||Proceedings of the KSME/JSME Joint Conference - Seoul, South Korea|
Duration: 1990 Jul 6 → 1990 Jul 7