Environmental cracking corrosion

Duquette, D. J., Mechanisms of crack initiation and propagation in corrosion fatigue , Proc. Int. Conf. on Mechanisms of Environmental Cracking in Materials, University of Surrey, 4-7 April 1977, The Metals Society, pp. 305-21 (1977)... 

It is often difficult to conduct laboratory tests in which both the environmental and stressing conditions approximate to those encountered in service. This applies particularly to the corrosive conditions, since it is necessary to find a means of applying cyclic stresses that will also permit maintenance around the stressed areas of a corrosive environment in which the factors that influence the initiation and growth of corrosion fatigue cracks may be controlled. Among these factors are electrolyte species and concentration, temperature, pressure, pH, flow rate, dissolved oxygen content and potential (free corrosion potential or applied). 

Panl Pankajavalli, R., Sreedharan, O.M. Proceedings of the Symposium on Localized Corrosion and Environmental Cracking, IGCAR, Kalpakkam, 1979, C55. 

Environmental Cracking The problem of environmental cracking of metals and their alloys is very important. Of all the failure mechanism tests, the test for stress corrosion cracking (SCC) is the most illusive. Stress corrosion is the acceleration of the rate of corrosion damage by static stress. SCC, the limiting case, is the spontaneous cracking that may result from combined effects of stress and corrosion. It is important to differentiate clearly between stress corrosion cracking and stress accelerated corrosion. Stress corro-... 

NACE International Standard RP0472-95, Methods and Controls to Prevent In-Service Environmental Cracking of Carbon Steel Weldments in Corrosive Petroleum Refining Environments. 

Aluminum and alloys are not suitable for (1) alkalis, (2) acids at pH 4.5, and (3) mercury, which can be a significant risk in some liquified natural gas operations. The heat treatable, high-strength aluminum alloys of the 2000- and 7000-series are rarely used because of environmental cracking susceptibility. Aluminum and its alloys are susceptible to chloride pitting and to concentration cell problems such as crevice corrosion and under-deposit corrosion. 

Schweitzer, Philip A., ed. 1996. Corrosion Engineering Handbook. New York Marcel Dekker. Caplan, F. 1975. Is Your Water Scaling or Corrosive Chemical Engineering September 1 29. NACE International. Current edition. Methods and Controls to Prevent In-Service Environmental Cracking of Carbon Steel Weldments in Corrosive Petroleum Refinery Environments. NACE RP0472. Houston, TX NACE International. 

In this chapter, we have not discussed materials corrosion under mechanical stresses, such as environmental cracking, stress corrosion cracking, erosion-corrosion, and cavitation-corrosion. 

Figure 7.13. Types of corrosion (environmentally affected) fatigue crack growth response...

Ignored by most implementations of the CCS framework, ohmic drop can not only lead to passive-to-active transitions, but also can, in the context of environmental cracking, make hydrogen evolution, and therefore embrittlement, more viable at the crack tip. The IR framework has been successfully demonstrated in several model metal/environment systems [34, 35], and has been invoked to rationalize the practically important case of the crevice corrosion of Alloy 625 in chlorinated seawater [32, 33]. 

Problems associated with size can be assessed by the principles for scaling corrosion tests. A report has been published by the European F eration of Corrosion Working Party on Thysicochemical methods of corrosion testing - fundamentals and application"[5] which includes information on specimen size for testing uniform, bimetallic and pitting corrosion and stress-assisted environmental cracking. 

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