Corrosion Fatigue Crack Growth Studies in Ni-Cr-Mn Steel

This paper presents the results of corrosion fatigue crack growth behaviour of a Ni-Cr-Mn steel commonly used in marine applications. The effect of mechanical variables such as frequency and load ratio on fatigue crack growth rate at various stages has been studied using compact tension (C(T)) specimens along the rolling direction of steel plate under 3.5% saturated NaCl aqueous environment. The significance of crack closure on corrosion fatigue, and the validity of Elber-s empirical linear crack closure model with the ASTM compliance offset method have been examined. Fatigue crack growth rate is higher and threshold stress intensities are lower in aqueous environment compared to the lab air conditions. It is also observed that the crack growth rate increases at lower frequencies. The higher stress ratio promotes the crack growth. The effect of oxidization and corrosion pit formation is very less as the stress ratio is increased. It is observed that as stress ratios are increased, the Elber-s crack closure model agrees well with the crack closure estimated by the ASTM compliance offset method for tests conducted at 5Hz frequency compared to tests conducted at 1Hz in corrosive environment.

Authors:

• Chinnaiah Madduri
• Raghu V. Prakash

Keywords:

• Corrosion fatigue
• oxide induced crack closure
• Elber's crack closure
• ASTM compliance offset method.

References:

[1] Alan F. Liu, Mechanics and Mechanisms of Fracture: An Introduction,
ASM International 2005.
[2] Carman, C. D., C. C. Turner, and B. M. Hillberry, A Method for
Determining Crack Opening Load from Load-Displacement Data,
Mechanics of Fatigue Crack Closure, ASTM STP 982, Philadelphia, pp.
214-221.
[3] Chiou, S., R. P. Wei, Corrosion-Fatigue: Cracking response of beta
annealed Ti-6Al-4V alloy in 3.5% NaCl solution, NADC-83126-60, U.S.
naval air development center, 1984.
[4] Crooker, T. W., R. W. Jody Jr, R. J. Goode, Fundamental
Considerations of Fatigue, Corrosion Cracking and Fracture in
Advanced Ship Structures, The society of naval architects and marine
engineers, Trinity , New York.
[5] Fonte, M.A., S. E. Stanzl-Tschegg, A. K. Vasudevan, The
microstructure and environment influence on fatigue crack growth in
7049 aluminum alloy at different load ratios, International journal of
fatigue, 23,2001.
[6] Hugh, L. Logan, Film-Rupture Mechanism of Stress Corrosion, Journal
of Research of the National Bureau of Standards, Vol. 48, No. 2,
February 1952.
[7] Jeffrey, T. Fong, Fatigue mechanism, ASTM special technical
publication 675 , Philadelplila, 1916.
[8] Kazuaki Shiozawa, Shuming Sun, and R.L. Eadie, Effect of Testing
Frequency on the Corrosion Fatigue of a Squeeze-Cast Aluminum Alloy,
Metallurgical And Materials Transactions A, Volume 31a, April 2000,
pp 1137-1145.
[9] McEvily, A.J., Atlas of stress corrosion and corrosion fatigue curves,
ASM International, Ohio, 1990.
[10] McEvily A.J and R.P.Wei , Corrosion fatigue - chemistry, mechanics
microstructure, NACE-2, 1972.
[11] Miller G.A, S. J. Hudak and R. P. Wei, Effect of loading variables on
environmental assisted fatigue crack growth in high strength steels,
Journal of testing and evaluation, JTEVA, Vol 1,Nov 1973, pp 524-531.
[12] Newman J.C. Jr and W. Elber (Editors), Mechanics of fatigue crack
closure, ASTM STP 982, West Conshohoken, PA, 1988.
[13] Pao P.S., W. Wei and R. P. Wei, Environment-Sensitive Fracture of
Engineering Materials, TMS-TIME,1979, pp. 565
[14] Parkins R.N., M.Ya. Kolotyrkin (Editors), Corrosion Fatigue,
Proceeding of the first USSR-UK seminar on Corrosion Fatigue of
Metals, Lvov, USSR 1980.
[15] Richard Roberts, Fracture Mechanics, ASTM STP 743, Philadelphia,
1986.
[16] Richard P. Gangloff, Environmental CrackingÔÇöCorrosion Fatigue, in
Chapter 26 - Corrosion tests and standards manual.
[17] Simmons, G. W., P. S. Pao and R. P. Wei, Fracture Mechanics and
Surface Chemistry Studies of Subcritical Crack Growth in AISI 4340
Steel, Metallurgical transaction. A, Vol. 9A, 1978, pp. 1147-58.
[18] Sivaprasad. S., S. Tarafder, V. R. Ranganath, M. Tarafder, and K. K.
Ray, Corrosion fatigue crack growth behavior of naval steels, Corrosion
Science, 48 ,2006.
[19] Suresh, S., G. F. Zamisky, and R.O.Ritchie, Oxide induced crack
closure an explanation for near threshold corrosion fatigue crack
growth behavior, Metallurgical Transaction -A, Vol. 12, 1981.
[20] Rolfe S.T., and J.M. Barsom, Fracture and Fatigue Control In
Structures, Prentice-Hall, 1977.
[21] Su-Pyun and Young -Gab Chun, Environmental effects on crack closure
of Aluminium -Lithium alloy, Corrosion Science, Vol. 13, 1993, pp.611-
619.
[22] Ugiansky.G.M,payer J.H .(Editors), Stress corrosion cracking -slow
strain rate technique, ASTM STP 665, Toronto, Canada, 1977.
[23] Vasudevan A.K., K. Sadananda, Classification of environmentally
assisted fatigue crack growth behavior, International Journal of Fatigue,
31, 2009, pp.1696-1708.