K. Kimura et al., EFFECTS OF MINOR ALLOYING ELEMENTS ON INH ERENT CREEP STRENGTH PROPERTIES OF FERRITIC STEELS, Tetsu to hagane, 81(7), 1995, pp. 757-762
Creep rupture strength properties of carbon steel have been analyzed f
rom a viewpoint of inherent creep strength, and the effects of minor a
lloying elements on inherent creep strength have been investigated. In
herent creep strength, which is a new concept proposed by the authors,
is an essential strength property independent of both microstructural
morphology and time, and the governing factor of long-term creep stre
ngth property. Large heat-to-heat Variation of inherent creep strength
observed for the carbon steel has been cleared to be caused by a rema
rkable improving effect of Mo on that, However, strengthening effect o
f Mo has been speculated to saturate at a slight amounts of about 0.03
mass%. It has been concluded that an inherent creep strength of ferrit
ic steel is governed by solid solution strengthening effect due to suc
h as C and Mo, and the maximum inherent creep strength is obtained by
the addition of C and about 0.03mass% of Mo. Moreover, it has been sug
gested that the inherent creep strength of many ferritic heat resistan
t steels are maximum level for ferritic steels, consequently, creep ru
pture strength of those converges to an almost same level at the long-
term region.