Corrosion fatigue fracture mechanics

Speidel, M.O., Stress Corrosion Cracking and Corrosion Fatigue - Fracture Mechanics, in Corrosion in Power Generating Equipment, M.O. Speidel, A. Atrens (eds.), Plenum Press, NY, pp. 85-132, 1984. 

A. Ptakash,D. K. Kim, and R. M. Shemeashi, International Conference on Fatigue, Corrosion Cracking Fracture Mechanical andFailure Analysis, ASM... 

Westwood, H.J., Lee, W.K., Corrosion-Fatigue Cracking in Fossil-Fueled Boilers, Corrosion Cracking, Proc. in the International Conf. on Fatigue, Corrosion Cracking, Fracture Mechanics and Failure Analysis, ASM, Salt Lake City, UT, pp. 23-34, 1986. 

McEvily, A. J., and Wei, R. P., Fracture Mechanics and Corrosion Fatigue, Corrosion Fatigue Chemistry, Mechanics and Microstructure, NACE-2 (1972), 281. 

Only a handful of titanium alloys have currently been FSWed. Considerable scope for investigation of other titanium alloys exists. Finally, property databases for first-tier (tensile) and second-tier (fatigue, fracture) mechanical properties are mandatory if designers are to use FSW of titanium alloys in future designs. Corrosion databases are also required for designers. 

Thus, as follows from mentioned above, the data on corrosion fatigue of Mg alloys are very contradictory. The present research is devoted to the correlation analysis of corrosion fatigue behavior of diecast and extruded Mg alloys in 3.5% NaCl (pH 5) and 0. IN Na2B407 solution with a stable pH of 9.3 (buffer solution) and to the investigation of fatigue fracture mechanisms of these alloys depending on chemical composition, e.g, A1 content, environment and microstructure. 

The NACE publication Corrosion Fatigue gives a comprehensive account of all aspects of the subject, and in this work a review of the application of fracture mechanics for studying the phenomenon has been presented by McEvily and Wei , whilst Kitagawa has given a detailed account of crack propagation in unnotched steel specimens. This work should be consulted for details of testing and interpretation of results. 

Structural failure may occur when the overall structural cross-section cannot support the applied load or, when the critical flaw size ac is exceeded by preexisting discontinuity or by reaching the critical crack size through fatigue, stress corrosion cracking or creep mechanisms. Using fracture mechanics the stress at a crack tip can be calculated by a stress-intensity parameter K as,... 

Structural failures in general occur by a combination of crack initiation followed by subcritical crack growth mechanism such as stress corrosion, fatigue, and creep until a critical crack size is reached. Thus, fracture mechanics is useful in evaluating ac that leads to failure by fracture. The application of fracture mechanics in failure analysis throws light on the progress from subcritical crack growth to fracture, the amount of load... 

Acta Metallurgica et Materialia Cement and Concrete Research Composite Structures Computers and Structures Corrosion Science Engineering Failure Analysis Engineering Fracture Mechanics European Journal of Mechanics A B International Journal of Fatigue International Journal of Impact Engineering International Journal of Mechanical Sciences International Journal of Non-Linear Mechanics International Journal of Plasticity... 

Effect on Confined Systems Corrosion Problems Fracture Fatigue Nano Characterisation Test Methodology Computer Simulation Surface Modification Surface Treatments Surface Problems in Contact Mechanics Fracture Mechanics Coupled Analysis and Experiments Thin Coatings Thick Coatings Contact Mechanics Material Surfaces in Contact Applications and Case Studies Indentation and Hardness Adhesion Bonding. 

Nevertheless at exploitation of airplanes during 15 years, in spite of insignificant stresses, cases of failures of the parts by means of a corrosion mechanism (intergranular brittle fracture) and by means of a combined corrosion-fatigue mechanism had taken place. 

From studies of service behavior and from extensive laboratory investigations, the well-established terms stress-corrosion cracking (SCC) and corrosion fatigue have been shown to relate to a continuum of failure modes classified as environment-sensitive fracture. In many environments, the addition of stress, with associated strains, introduces a variable that can result in brittle failure in the sense of very limited plastic flow in otherwise ductile materials such as the stainless steels. Environment-sensitive fractures propagate at an advancing crack tip at which, simultaneously, the local stresses can influence the corrosion processes, and the corrosion can influence the crack-opening processes. Since these processes proceed by kinetic mechanisms, they are time and stress dependent with the result that the crack propagation rate can become very sensitive to the stress application rates. Conventional SCC usually has been associated with static stress, but this is seldom realized... 

F.P. Ford, Current Understanding of the Mechanisms of Stress Corrosion and Corrosion Fatigue, Environment-Sensitive Fracture Evaluation and Comparison of Test Methods, STP 821, S.W. Dean, E.N. Pugh, and G.M. Ugiansky, Ed., ASTM, 1984, p 32-51... 

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