The wedge-crack growth model proposed by Williams for creep rupture has been modified by inclusion of the Cottrell criterion for crack instability. By combining this model with empirical relationships between strain rate, grain-boundary sliding rate, stress, and grain size, it can be applied to conditions of high-strain-rate deformation where the grain size may be established by dynamic recrystallization. Comparison of predicted rupture times with experimental results obtained in torsion indicates that control of ductility by wedge-crack growth is reasonable under these conditions and that the occurrence of dynamic recrystallization significantly decreases crack growth rates.
Get full access to this article
View all access options for this article.
References
1.
JonasJ., SellarsC. M., and McGW. J.. Tegart, Met. Rev., 1969, 14, (130), 1.
2.
SellarsC. M. and TegartW. J. McG., Internat. Met. Rev., 1972, 17, I.
3.
LutonM. J. and SellarsC. M., Acta Met., 1969, 17, 1033.
4.
WhiteF. E. and RossardC., ‘Deformation under Hot Working Conditions’ (Special Rep.No. 108), p. 4. 1968: London(Iron Steel Inst.).
5.
LutonM. J. and TegartW. J. McG., Metal Scl. J., 1969,3, 142.
