| 摘要 |
PURPOSE:To make possible a presumption of the expiration data of metallic material by a nondestructive inspection, by determining a necessary parameter corresponding to prescribed physical quantities of the metallic material being used at a high temperature and performing an operation based on the damage rate corresponding to measured value of hardness and the parameter. CONSTITUTION:A parameter P corresponding to an actually measured resistance ratio Rrho is determined from the curve for the ratio Rrho of respective electric resistances of metallic material being used at a high temperature plus at a low temperature and the parameter P such as a temperature T, working time t. A necessary damage rate phic is obtained from Hv-P curve of each damage rate phic by said parameter P plus measured hardness Hv and a remaining life t2 is computed by performing an operation on the basis of the equation I. Hereby, the expiration data of the metallic material can be presumed by a nondestructive inspection. Here, t1 is presuming working time. |
