Stress corrosion cracking definition

The failure time, however, incorporates both the time required for crack initiation and a period of slow crack growth so that the separate effect of the environment on each of these stages cannot be ascertained. (Some of the difficulty stems from the lack of a precise definition for crack initiation.) This difficulty is underscored by the results of Brown and Beachem [1] on SCC of titanium alloys. They showed that certain of the alloys that appeared to be immune to stress corrosion cracking in the traditional (smooth specimen) tests are, in fact, highly susceptible to environment-enhanced crack growth. The apparent immunity was explained by the fact that these alloys were nearly immune to pitting corrosion, which was required for crack nucleation in the same environment [1]. 

In accordance with these definitions, stress-corrosion cracking has been a familiar problem in the petroleum and chemical industries for decades. Consequently, measures seem to be rather well established and generally known for preventing stress-corrosion cracking or for keeping it in check. Where conditions are such that this type of hydrogen attack can be expected, appropriate supplemental requirements should be included in the specification. A vessel built only to code requirements could be rendered unserviceable in a matter of hours by stress-corrosion cracking. 

Definition and Characteristics of Stress Corrosion Cracking Testing Methods... 

In the more recent literature, the term strain-induced corrosion is commonly found, which is a generic term for nonclassical stress corrosion cracking, corrosion fatigue with low cycle frequency, and strain-induced corrosion cracking. For the purposes of a clear distinction between the different types of cracking, this term should be replaced by the definitions below. 

The depths of deepest pits on specimens, the times to first leaks in pipe lengths, times to initial stress-corrosion cracking failures, and the number of cycles to first corrosion-fatigue failures are, by definition, extreme values. The depth of the deepest pit on a specimen is the upper tail of the distribution of depths of all pits on that specimen. 

From the ASTM definition, stress corrosion cracking is the simultaneous action of a corrosive environment and a sustained tensile stress promoting rupture" [54]. Both SCC and deallo)dng often occur in the same environment. By the 1940s, deaUoying was considered to be involved in the initiation of SCC [57]. 

Dry chlorine is defined as chlorine with its water content dissolved in solution. An exact definition of dry and wet chlorine supported by charts of water solubility in chlorine as a fimction of temperature can be found in Chlorine Institute publications [7, 8]. In general, steel piping is recommended for handling dry chlorine. Stainless steels of the Type 300 series have useful properties for service at low temperatures, but can fail due to chloride stress corrosion cracking, particularly in the presence of moisture at ambient or elevated temperatures. 

Stress corrosion cracking, 38-18 Stressed volume, definition, 58-2 Strich, S.J., 52-2 Stride and temporal parameters, in gait analysis, 51-3 Stroke volume (SV), 1-6 Stupp, S.I., 46-10 Sturdivan, L.M., 53-6 Subretinal retinal stimulation, 35-2... 

This behavior is characterized by a plateau region, which prevails above a definite threshold K. It is often referred to as stress-corrosion fatigue because SCC systems usually exhibit this behavior, and the most common theory assumes that the crack growth rate results from the addition of SCC, and pure fatigue crack advance. This is a type of... 

FYom the multitude of intricate corrosion processes in the presence of mechanical action (friction, erosion, vibration, cavitation, fretting and so on) it is justified to touch upon corrosion types joined under a single failure mode induced by mechanical stresses. These are the stresses that govern the corrosion wear rate of metals during friction. Such processes are usually called corrosion stress-induced cracking in the case that the mechanical action is effective only in one definite direction, or otherwise termed corrosion fatigue in the case that compressive and tensile stresses alternate within cycles. In spite of the differences between the appearance of these corrosion types, they have much in common, e.g. fundamental mechanisms, the causes, and they overlap to a certain degree [19]. 

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