Room Temperature Creep and its Effect on Fatigue Crack Growth in a X70 Steel with Various Microstructures


Article Preview

Fatigue crack growth (FCG) tests have been performed in an X70 steel with various microstructures (respectively in the as-received and the normalized condition). The effect of room temperature creep (RTC) on FCG behavior has been investigated by comparing with single wave overloads (SWOL). The as-received X70 pipeline steel has high FCG rate at the near-threshold region. While at the Paris region, FCG rate seems insensitive to the microstructure. In both conditions, time-dependent deformation is observed at crack tips (i.e., RTC), which increases with increasing stress-intensity-factor. And this deformation has a high value in the normalized state, under identical testing conditions. Both RTC and SWOL can bring subsequent fatigue crack growth a very short initial acceleration before deceleration, whereas the former induces more serious deceleration and retardation, which attributes to more significant crack closures.



Key Engineering Materials (Volumes 353-358)

Edited by:

Yu Zhou, Shan-Tung Tu and Xishan Xie




D. F. Nie and J. Zhao, "Room Temperature Creep and its Effect on Fatigue Crack Growth in a X70 Steel with Various Microstructures", Key Engineering Materials, Vols. 353-358, pp. 138-141, 2007

Online since:

September 2007





[1] S.H. Wang, Y.G. Zhang and W.X. Chen: J. Mater. Sci. Vol. 36 (2001) , p.1931-(1938).

[2] S.H. Wang and W.X. Chen: Mater. Sci. Eng. A301 (2001), pp.147-153.

[3] S.H. Wang and W.X. Chen: Mater. Sci. Eng. A325 (2002), pp.144-15.

[4] D.F. Nie, J. Zhao and T. Mo: J. Mater. Eng. Vol. 6 (2006) , pp.58-61 (in Chinese).

[5] D.F. Nie, H.X. Zhang and J. Zhao: Transactions of Materials and Heat Treatment. Vol. 27 No. 4 (2006), pp.47-51 (in Chinese).

[6] C.S. Shin and S.H. Hsu: Int. J. Fatigue. Vol. 15 No. 3 (1993), pp.181-192.

[7] M. Shimojo, M. Chujo, Y. Higo and S. Nunomura: Int. J. Fatigue. Vol. 20 No. 5 (1998), pp.365-371.

[8] H. Bao and A.J. McEvily: Int. J. Fatigue. Vol. 20 No. 6 (1998), pp.441-448.

[9] K. Sadananda, A.K. Vasudevan, R.L. Holtz and E.U. Lee: Int. J. Fatigue. Vol. 21 (1999), p. S233-S246.

[10] M. darvish and S. Johansson: Eng. Fract. Mech. Vol. 52 No. 2 (2003), pp.295-319.

[11] L.P. Borrego, J.M. Ferreira, J.M. Pinho da Cruz and J. M. Costa: Eng. Fract. Mech. Vol. 70 (2003), pp.1379-1397.

[12] J. Zhao, T. Mo, D.F. Nie, M.F. Ren and X.L. Guo, Journal of Materials Science. In press.

[13] J. Zhao, T. Mo, W.X. Chen and F.G. Wang: Key Engineering Materials. (2005), Advances in Fracture and Strength, pp.1083-1088.

[14] ASTM Standard E647-05: Standarc Test Method for Measurement of Fatigue Crack Growth Rates. (2005).

[15] T.H. Alden: Metall. Trans. A 18 A (1987), pp.811-825.

[16] T.H. Alden: Metall. Trans. A 18 A (1987), pp.51-62.