Influence of strain rate on near-neutral pH environmentally assisted cracking of pipeline steels
FANG Bingyan; HAN Enhou; WANG Jianqiu; KE Wei
Environmental Corrosion Center; Institute of Metal Research; The Chinese Academy of Sciences
Cite this article:
FANG Bingyan; HAN Enhou; WANG Jianqiu; KE Wei. Influence of strain rate on near-neutral pH environmentally assisted cracking of pipeline steels. Acta Metall Sin, 2005, 41(11): 1174-1182 .
Abstract Environmentally assisted cracking (EAC) of X-70 pipeline steels in near-neutral pH environments, including the standard solution, NS4, and an actual soil solution, was investigated using constant loading tests, slow strain rate tests (SSRT) and cyclic loading tests. It was revealed that local strain rate is a key factor that builds a bridge between different tests, different samples and different cracking processes, and dominates fracture mode. Therefore, local strain rate is one of the most important parameters in the EAC of X-70 pipeline steels. Stress corrosion cracking (SCC) can occur only if the local strain rate is smaller than the upper susceptible local strain rate for SCC, i.e. 5×10-5 s-1. As for cyclic loading tests, when the local strain rate is higher than this upper local strain rate for SCC, corrosion fatigue (CF) will occur. Further more, mechanical facture will take place if the local strain rate is high enough. Meanwhile, it is shown that as far as the EAC of X-70 pipeline steels in near-neutral pH environments is concerned, the cracking is dominated by the local strain rate no matter which the mechanism is, dissolution or (and) hydrogen related process. Thus the mechanism of the near-neutral pH cracking for X-70 in-service pipelines in the field is SCC instead of CF. In addition, it is proposed that the term of near-neutral pH SCC is inappropriate, which should be replaced by near-neutral strain assisted corrosion cracking to better describe the EAC of X-70 pipeline steels that is, in fact, local-strain-rate-based environmentally cracking.
[1] Staehle R W. In: Jones R H ed., Chemistry and Electrochemistry of Corrosion and Stress Corrosion Cracking: A Symposium Honoring the Contributions of Staehle R W, New Orleans, LA: TMS, 2001: K-1 [2] Wei R P, Landes J D. Mater Research and Standards, 1969; 9: 25 [3] Weir T W, Simmons G W, Hart R G, Wei R P. Scr Metall, 1980; 14: 357 [4] Wei R P, Simmons G W. Int J Fatigue, 1981; 17: 235 [5] Wei R P, Gao M. Scr Metall, 1983; 17: 959 [6] Austen I M, Mclntyre P. Met Sci, 1979; 13: 420 [7] Ford F P. In: Gangloff R P, Ives M B eds., Proce First Int Conf Environment-Induced Cracking of Metals, Houston, Texas: NACE, 1988: 139 [8] Jones R H. Stress-Corrosion Cracking: Materials Performance Evaluation, Metals Park, Ohio: ASM International, The Materials Information Society, 1992: 32 [9] Romanov V V. Stress- Corrosion Cracking of Metals, Washington D.C. Trans Technol House, 1961: 29 [10] Congleton J, Shoji T, Parkins R N. Corros Sci, 1985; 25: 633 [11] Shoji T, Suzuki S, Ballinger T G. Proc on 7th Int Symp on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors, Breckenbidge, Colorado: NACE, 1995: 881 [12] Suzuki S, Shoji T, Yi Y S, Kim J. Proc on 8th Int Symp on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors, Amelia Island, Plantation, FL: American Nuclear Society, 1997: 695 [13] Fang B Y, Atrens A, Wang J Q, Han E H, Zhu Z Y, Ke W. J Mater Sci, 2003; 38(1): 127 [14] Fang B, Han E, Zhu Z, Wang J, Ke W. J Mater Sci Technol, 2002; 18: 3 [15] National Energy Board, Canada, MH-2-95, 1996 [16] Parkins R N, Beavers J A. Corrosion, 2003; 59: 258 [17] Ford F P. Corrosion'86, Houston, Texas: NACE, 1986: paper No.327 [18] Ford F P, Taylor D F, Andresen P L, Ballinger R G. Elctric Ponwer Research Institute Report NP5064S, 1987 [19] Elboujdaini M, Wang Y Z, Revie R W, Parkins R N, She-hata M T. Corrosion'2000, Houston, Texas: NACE, 2000: Paper No.00379 [20] Department of Tranportation, Research and Special Programs Adminstration, Office of Pipeline Safety, Final Report on Stress Corrosion Cracking Study, TTO Number 8, Integrity Management Program, Delivery Order DTRS56-02-D-70036, Moon Township, PA, 2005 [21] Williams B W, Lambert S B, Zhang X, Plumtree A, Sutherby R. In: Luo J, Shoesmith D, Elboujdaini M, Pat- naik P eds., 2nd Int Symp on Environmental Degradation of Materials and Corrosion Control in Metals as held at the 42nd Annual Conference of Metallurgists of CIM (COM 2003), Vancouver, Canada: CIM, 2003: 87 [22] Ahmed T M, Lambet S B, Sutherby R, Plumtree A. Corrosion,1998; 54: 115 [23] Pikey A K, Lambert S B, Plumtree A. Corrosion, 1995; 52: 91 [24] Plumtree A, Lambert S B, Sutherby R. EUROCORR'96, Nice, France: European Corrosion Congress, 1996: 262 [25] Zhang X Y, Lambert S B, Surtherby R, Plumtree A. Cor-rosion, 1999; 55: 297 [26] Lambert S B, Beavers J A, Delanty B, Sutherby R, Plumtree A. Proc Int Pipeline Conf, New York: ASME, 2000: 961 [27] Williams B W, Lambert S B, Sutherby R, Plumtree A. Corrosion, 2004; 60: 95 [28] Ahmed T M, Lambert S B, Sutherby R, Plumtree A. Corrosion, 1997; 53: 581 [29] Plumtree A, Lambert S B. In: Elboujdaini M, Ghali E, Zheng W eds., Symposium on Environmentally Induced Cracking of Metals and Alloys, Ottawa: The Metallurgical Soceity of CIM, 2000: 7 [30] Bainbridge D, Lambert S B, Jack T R, Sutherby R, Plumtree A. EUROCORR 2001, Lake Garda, Italy: The European Corrosion Congress, 2001: 4 [31] Lambert S B, Plumtree A. EUROCORR 2001, Lake Garda, Italy: The European Corrosion Congress, 2001: 6 [32] Lambert S B, Plumtree A, Sutherby R. Corrosion'2000, Orlando, FL: NACE, 2000: paper No.00364 [33] Plumtree A, Lambert S B, Sutherby R. EUROCORR '99, Aachen, Germany: The European Corrosion Congress, 1999: 269 [34] Eadie R L, Szklarz K E, Sutherby R L. Corrosion, 2005; 61: 167 [35] Been J, Lu H, Eadie R, Shen G, Sutherby R. Corro-sion'2004, Houston, Texas: NACE, 2004: paper No.04552 [36] Wang S H, Chen W, Jack T, King F, Fessler R R, Krist K. Proc 2000 Int Pipeline Conf, New York: ASME, 2000: 1005 [37] King R, Jack R, Chen W, Wang S H, Elboujdaini M, Revie W, Worthingham R, Dusek P. Corrosion'2001, Houston, Texas: NACE, 2001: paper No.01214 [38] Wang Y Z, Revie R W, Shehata M R, Parkins R N, Krist K. Proc Int Pipeline Conf, Vol.1, New York: ASME, 1998: 529 [39] Elboujdaini M, Wang Y Z, Revie R W. Proc Int Pipeline Conf, Vol.2, New York: ASME, 2000: 967 [40] Wang Y Z, Revie R W, Shehata M T. Gas Research Institute Report MTL97-63(CF),1997 [41] Been J, Elboujdaini M, Revie R W, de Silveira G. Materials Technology Laboratory, S001-55(CF), 2000 [42] Kim B A, Zheng W, Williams G, Laronde M, Gianetto J A, Shen G, Tyson W R, Oguchi N, Hosokawa Y. Proc of 2004 Int Pipeline Conf, New York: ASME, 2004: Paper IPC04-0280 [43] ASTM Standard E8M-01, 2001 [44] ASTM Standard G1S9-00, 2000 [45] ASTM Standard E647-00, 2000 [46] Zhou X, Ke W, Zang Q. Acta Metall Sin (Engl Lett), 1990; 3: 320 [47] Zhou X Y, Ke W. Acta Metall Sin, 1992; 28: 356 (周向阳,柯伟．金属学报,1992;28:356) [48] Tada H, Paris P C, Irwin G R. The Stress Analysis of Cracks Handbook. 3rd ed., New York: ASME Press, The American Society of Mechanical Engineers, 2000 [49] Gao Y C, Hwang K C. In: Francois D ed., Advances in Fracture Research: 5th Int Conf on Fracture, Cannes, France: ICF, 2, 1981: 669 [50] Dean R, Hotchinson J W. ASTM STP 700, 1980: 383 [51] Lam P S, McMeeking R M. J Mech Phys Solids, 1984; 32: 395 [52] Drugan W J, Rice J R, Sham R L. J Mech Phys Solids, 1980; 30: 447 [53] Fang B, Han E H, Wang J, Ke W. Corrosion, in press [54] Tromans D. Metall Trans, 1981; 12A: 1445 [55] Pickens J R, Christodoulou L. Met Trans, 1987; 18A: 135 [56] Parkins R N. In: Bruemmer S M, Meletis E I, Jones R H, Gerberich W W, Ford F P, Staehle R W eds., Proc of Parkins Symp on Fundamental Aspects of Stress Corrosion Cracking, Cincinnati, Ohio: TMS, 1991: 1 [57] Fang B Y, Han E H, Wang J Q, Zhu Z Y, Ke W. J Mater Sci, in press [58] Johnson H H, Lin R W. In: Bernstein I M, Thompson A W eds., Hydrogen Effects in Metals, New York: AIME, 1981: 3 [59] Sofronis P, McMeeking R M. J Mech Phys Solid, 1989; 37: 317 [60] Krom A H M, Koers R W J, Bakker A. J Mech Phys Solid, 1999; 47: 971 [61] Fang B Y. PhD Dissertation, Institute of Metal Research, The Chinese Academy of Sciences, Shenyang, 2005 (方丙炎．中国科学院金属研究所博士学位论文,沈阳,2005) [62] Oriani R A. Acta Metall, 1970; 18: 147 [63] Parkins R N, Blanchard W K Jr, Delanty B S. Corrosion, 1994; 50: 394s
