ENVIRONMENT INDUCED CRACKING

Environment induced cracking of metals includes the following phenomena  

Stress corrosion cracking (SCC) is caused by the combined action of a static tensile stress and corrosion. The stress may originate from external loading or be the result of a thermal or mechanical treatment that generates residual stresses in the material. Stress corrosion cracking failures usually occur with some delay and they are limited to particular alloy-environment combinations, temperature ranges and stress levels. 

Hydrogen embrittlement designates a premature failure of a metal or alloy caused by the absorption of hydrogen. In certain cases, stress corrosion cracking is accompanied by hydrogen embrittlement at the crack tip and it is then difficult to separate the two phenomena. 

Corrosion fatigue is the result of the combined action of cyclic loading and corrosion. It manifests itself as a decrease in the endurance limit of the metal. 

Fractures resulting from environment induced cracking share two common characteristics  

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Sangloff, R. P. and Ives, M. B., (eds.) Environment-Induced Cracking of Metals, NACE, Houston (1990)... 

Duquette, D.J., Corrosion Fatigue Crack Initiation Processes A State-of-The-Art Review, in Environment-Induced Cracking of Metals, R.P. Gangloff, M.B. Yves (eds.), NACE-10, Houston, TX, p. 45, 1990. 

Wang, Y., Peng, X., Chu, W.Y., Su, Y.J., Qiao, L.J., and Gao, K.W., Anisotropy of hydrogen fissure and hydrogen-induced delayed fracture of a PZT ferroelectric ceramic, in Proceedings of the 2nd International Conference on Environment Induced Cracking of Metals, Banff, Canada, October 2004, in press. 

BP Somerday, SX McFadden, DK Balch, JD Puskar, and CH Cadden, Hydrogen-assisted fracture of inertia welds in 21Cr-6Ni-9Mn stainless steel , in Environment-induced Cracking of Materials, S Shipilov, RH Jones, J-M Olive, and R Rebak, Eds., Elsevier, Amsterdam, vol. 1, 2008, pp. 305-314. 

G.S. Duffo, J.R. Galvele, Surface-mobdity stress corrosion cracking mechanism in silver alloys, in R.P. Gangloff, M.B. Ives (Eds.), Environment-induced Cracking of Metals, NACE, Houston, TX, 1990, pp. 261—264. 

R. N. Parkins, Stress corrosion cracking, in Environment-Induced Cracking of Metals, Proceedings of the First International Conference on Environment-Induced Cracking of Metals, October 1988, R. P. Gangloff and M. B. Ives, editors. National Association of Corrosion Engineers, Houston, TX, 1990, p. 10. 

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