2001 Volume 87 Issue 7 Pages 508-514
Ferritic heat-resisting steels are planned to be applied to ultra supercritical power plants. In this study, creep-fatigue properties for base metals such as Mod.9Cr-1Mo, 9Cr-2W, 12Cr-2W, newly produced Pd-added ferritic steel and oxide dispersion strengthened ferritic steels and for welded joints of two kinds of the ferritic steels were investigated.
The creep-fatigue lives of the base metals, tested by trapezoidal strain wave shape with 3 hr-hold at tension side, were dependent on the kind of the materials and had a good correlation with the reduction of area for each material in the creep rupture tests.
The creep-fatigue lives for welded joint of 12Cr-2W and 9Cr-2W steel plates were about 70%, compared with the base metals.
The welded joints were fractured at fine-grained HAZ (heat affected zone).
