Stress- Corrosion Crack Initiation of High-strength Pipeline Steel in Near-neutral pH Environments

Document Type: Research Paper

Authors

1 Environmental Corrosion Center, Institute of Metal Research Chinese Academy of Science, Shenyang, P. R. China, 10016 and CANMET Materials Technology Laboratory 568 Booth Street, Ottawa, Ontario, Canada K1A 0G1

2 Environmental Corrosion Center, Institute of Metal Research Chinese Academy of Sciences, Shenyang, P. R. China, 10016

3 CANMET Materials Technology Laboratory 568 Booth Street, Ottawa, Ontario, Canada K1A 0G1

Abstract

Stress-corrosion cracking (SCC) tests were conducted in the near-neutral pH standard solution, NS4, and in an actual soil solution, using four-point bending at a high stress ratio and low frequency conditions very similar to those of operational pipelines. Pitting incubation appeared first and then pitting initiated and grew in both solutions although there were many more pits on the specimen tested in soil purged with 5% CO2 +95%N2 than in the specimen tested in NS4 solution purged with the same gas. These observations show that samples in soil solution are more susceptible to pitting than those in NS4 solution. When the pit reached a critical size, the increased stress concentration around the pits, resulted in transition to a crack.

Keywords


[1] P. N. Parkins, Corrosion/2000, Paper No. 00363, NACE Int., 2000.

[2] T. N. Baker, C. G. Rochfort, R.N. Parkins, Oil and Gas J., 85 (1987), 37.

[3] B. Delanty, J. O'Beirne, Oil and Gas J. 90 (1992), 39.

[4] National Energy Board, Report of Public Inquiry Concerning Stress-Corrosion Cracking on Canadian Oil and Gas Pipelines, MH-2-95, 1996.

[5] R. N. Parkins, J. A. Beavers, Corrosion. Vol. 59, No. 3, Mar. 2003, 258-273.

6. X. Y. Zhang, S. B. Lambert, R. Sutherby and Plumtree, " Transgranular Stress-Corrosion Cracking of X-60 Pipeline Steel in Simulated Ground Water", Corrosion 59 (2003), 258.

[7] R. N. Parkins, W. K. J. Blanchard and B. S. Delanty, Corrosion, 50 (1994), 394.

[8] R. R. Fessler, K. Krist, Corrosion/2000, paper No. 00370, NACE Int., (2000).

[9] M. Elboujdaini, Y. Z. Wang, R. W. Reivie, R. N. Parkins and M. T. Shehata, Corrosion/2000, Paper No. 00379, NACE Int., (2000).

[10] Y. Z. Wang, R. W. Revie, M. T. Shehata, R.N. Parkins and K. Krist, Int. Pipeline Conf., ASME ,(1998), 529.

[11] Y. Z. Wang, R. W. Revie, M. T. Shehata, R.N. Parkins, Materials for Resource Recovery and Transport, L. Collins, Editor, CIM, (1998), 71.

[12] M. Elboujdaini, Y. Z. Wang and     R. W. Revie, 2000 Int. Pipeline Conf., ASME, (2000), 967.

[13] F. King, T. Jack, W. Chen, S. Wang, M. Elboujdaini, R. W. Revie, R. Worthingham and P. Desuk, Corrosion/2001, Paper No. 01214, NACE Int. (2001).

[14] ASTM Standard E8-01 “Standard Test Methods for Tension Testing of Metallic Materials”, (2001).

[15] Y. Kondo, Corrosion, 45 (1989), 7.

[16] G. C Chen, C. M. Liao, K. C. Wan, M. Gao and R. P. Wei, ASTM STP 1298, (1997), 18.

[17] R. P. Wei, ASTM STP 1401, (2000), 3.

[18] W. D. Pikey, “Peterson,s Stress Concentration Factors”, 2nd Edition,NY,NY:Rexdale,Ontario, Wiley, (1997).

[19] R. P. Wei, D. G. Harlow, Proc. of Corros./2003 Research Topical Symp. Modeling and Prediction of Lifetimes for Corrodible Structures, 206.

[20] R. P. Gangloff, R. O. Ritchie, Fundamentals of Deformation and Fracture, K. J. Miller, Editor, Cambridge University Press, (1984).

[21] J. A. Beavers, C. L. Durr, B. S. Delanty, D. M. Owen and R. L. Sutherby, Corrosion/2001, Paper No.01217 NACE Int., (2001).

[22] Michael Baker Jr., Ink., Integrity Management Program ,(2004).