Prediction of Cleavage Fracture in the Ductile-to-Brittle Transition Region of Pressure Vessel Steels: A Probabilistic Model

Abstract:

This paper presents a modified Weibull stress model, which accounts for the effects of plastic strain and stress triaxiality at the crack tip region. The proposed model is applied to predict cleavage fracture in a modified A508 pressure vessel steel. It is demonstrated that the Weibull modulus (m) remains constant in the temperature range considered, while the threshold Weibull stress (σw-min) decreases with an increase in temperature due to reduction of the yield stress and the scale parameter of the Weibull model (σu) increases with temperature reflecting the influences of temperature on both material flow properties and toughness. The proposed model accurately predicts the scatter of the measured fracture toughness data and the strong effects of constraint and temperature on cleavage fracture toughness.

• Periodical: Key Engineering Materials (Volumes 324-325)
• Pages: 283-286
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.324-325.283
• Online since: November 2006
• Authors: Xiao Sheng Gao, Gui Hua Zhang, T.S. Srivatsan
• Keywords: Cleavage Fracture, Constraint Effect, Failure Probability, Plastic Strain, Stress Triaxiality, Temperature Effect, Weibull Stress

References

[1] F.M. Beremin: Metall. Trans. Vol. 14A (1983), p.2277.

[2] X. Gao, C. Ruriggieri and R.H. Dodds: Int. J. Fract. Vol. 92 (1998), p.175.

[3] X. Gao, R.H. Dodds, R.L. Tregoning, J.A. Joyce and R.E. Link: Fatigue Fract. Engng Mater. Struct. Vol. 22 (1999), p.481.

[4] T.G. Lindley, G. Oates and C.E. Richards: Acta Metall. Vol. 18 (1970), p.1127.

[5] J. Gurland: Acta Metall. Vol. 20 (1972), p.735.

[6] X. Gao, G. Zhang and T.S. Srivatsan: Mater. Sci. Eng. Vol. 394A (2005), p.210.

[7] ASTM E-1921 (1998).

[8] J. Faleskog, M. Kroon and H. Oberg: Engng Fract. Mech. Vol. 71 (2004), p.57.

[9] J. Petti and R.H. Dodds: Engng Fract. Mech. Vol. 72 (2005), p.91.