Abstract
Hydrogen induced cracking (HIC) and stress corrosion cracking (SCC) of a high-strength steel 34CrNi3Mo (T.S = 1700 MPa) under Mode II loading were investigated using notched specimens. The stress field around the notch tip was analyzed by means of finite element method. The result shows HIC and SCC under Mode II loading initiated at the back of the notch tip,i.e., θ = -110 deg, where hydrostatic stress has maximum value. However, cracking is oriented along the shear stress direction at the site, not normal to the direction of maximum principal stress component. On the contrary, if the specimens are loaded to fracture in air under Mode II loading, cracking at the maximum shear stress site around the notch tip and the cracking direction coincide with the direction of the maximum shear stress. The above facts indicate that hydrogen induced delayed plastic deformation is a necessary condition for HIC, and the nature of SCC for high-strength steel in 3.5 pct NaCl solution is HIC. The results show that HIC and SCC under Mode II loading can occur during dynamic charging with hydrogen and in 3.5 pct NaCl solution, respectively. The normalized threshold stress intensity factors under Mode II loading during dynamic charging in 1 N H2SO4 + 0.25 g As2O3/L solution and in 3.5 pct NaCl solution are KIIH/KIIX = 0.1 and KIISCC/KIIX = 0.45, respectively. The corresponding values under Mode I loading are KIH/KIX = 0.02 and KISCC/KIX = 0.37, where KIIX and K,IX are critical values loaded to failure in air under Mode II and Mode I loading, respectively. Thus, (KIIH/KIIX)/ KIH/KIX) = 5 and (KIISCC/KIIX)/K,(ISCC/KIX) = 1.2. A typical intergranular fracture was observed during HIC and SCC under Modes II and I loading. But the fracture surfaces of specimens failed in air are composed of dimples for both kinds of loading.
Similar content being viewed by others
References
W. Y. Chu, C. M. Hsiao, S. Q. Li, and J. Z. Tien:Corrosion, 1980, vol. 36, pp. 475–81.
W. Y. Chu, S.Q. Li, C. M. Hsiao, and C. Wang:Acta Met. Sinica (China), 1981, vol. 17, pp. 10–17.
W.Y. Chu, T.H. Liu, C. M. Hsiao, and S.Q. Li:Corrosion, 1981, vol. 37, pp. 320–27.
W. Y. Chu, C. M. Hsiao, W. X. Li, and Y. G. Zhang:Metall. Trans. A, 1984, vol. 15A, pp. 2087–92.
W. Y. Chu, C. M. Hsiao, S. Y. Ju, and C. Wang:Corrosion, 1982, vol. 38, pp. 446–52.
W. Y. Chu, T. Y. Zhang, and C. M. Hsiao:Corrosion, 1984, vol. 40, pp. 197–99.
K. F. McGuinn and M. Aballe:Brit. Corros. J., 1982, vol. 17, no. 1, pp. 18–20.
R. Magdowski and W. W. Gerberich:Scripta Metall., 1983, vol. 17, pp. 421–22.
F. A. Nichols:Corrosion, 1983, vol. 39, pp. 449–51.
C. Chen, Q. G. Cai, and R. Zh. Wang:Engineering Fracture Me- chanics, National Defence Industry Press, China, 1977, vol. 1, p. 54.
W.Y. Chu:Fundamentals of Fracture Mechanics, Science Press, China, 1979, p. 288.
W. Y. Chu, Y. B. Wang, and C. M. Hsiao:Corrosion, 1982, vol. 38, pp. 561–70.
W. Y. Chu, H. Li. Wang, and C. M. Hsiao:Corrosion, 1984, vol. 40, pp. 487–92.
T. D. Lee, T. Goldenberg, and J. P. Hirth:Fracture 1977, D. M. R. Taplan, ed., Pergamon, Oxford, 1977, vol. 2, pp. 243–48.
T. D. Lee, T. Goldenberg, and J. P. Hirth:Metall. Trans. A, 1979, vol. 10A, pp. 199–208, pp. 439–48.
T. Tabata and H.K. Birnbaum:Scripta Metall., 1983, vol. 17, pp. 947–50.
Y.B. Wang, W.Y. Chu, and C.M. Hsiao:Scripta Metall., 1985, vol. 19, no. 10, pp. 1157–66.
T.Y. Zhang, W.Y. Chu, and C. M. Hsiao:Metall. Trans. A, 1985, vol. 15A, pp. 1649–54.
T. Y. Zhang, W. Y. Chu, and C. M. Hsiao:Scientic Sinica, Series A (China), in press.
Author information
Authors and Affiliations
Additional information
Formerly Student at Beijing University of Iron and Steel Technology
Rights and permissions
About this article
Cite this article
Zhang, TY., Chu, WY., Li, Y. et al. Hydrogen-induced delayed fracture under mode II loading. Metall Trans A 17, 717–725 (1986). https://doi.org/10.1007/BF02643993
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02643993