| 摘要 |
PROBLEM TO BE SOLVED: To improve prediction accuracy of creep rupture strength of a precipitation strengthening type Ni base superalloy and evaluation accuracy of a residual service life after actual machine use, and to secure long-term reliability of a high temperature component.SOLUTION: A creep rupture test in limited time is performed, rupture stress &sgr; and creep rupture time twhich are the results thereof are used to determine a stress index n of a creep deformation speed and a constant Cin a following equation (5) from following equations (5)-(7) and (2), and long-term creep strength of a precipitation strengthening type heat resistant alloy is estimated using the following equations (5)-(7) and (2): ln&sgr;=-(1/n)lnCMP+C...(5), CMP=((&pgr;/F)-2)(d-d)...(6), d=(kt+d)...(7), and k=(C/T)exp(-Q/RT)...(2). |
