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PRCI PR-230-9914
- Conditions that Lead to the Generation of SCC Environments - A Review
- Report / Survey by Pipeline Research Council International, 01/01/2000
- Publisher: PRCI
$198.00$395.00
L51911e
CANMET Materials Technology Laboratory
Need: There are several types of environmentally-assisted cracking that can be of concern to pipeline operators, including hydrogen-induced cracking (HIC), stress-oriented hydrogen-induced cracking (SOHIC), and stress corrosion cracking (SCC), which may be either transgranular or intergranular. This review is concerned with SCC, which usually initiates on the external surface of the pipeline, under the combined influence of stress and ground water or some derivative of the latter.
Result: Current knowledge of the conditions leading to generation of environments that cause stress corrosion cracking (SCC) of high-pressure pipelines was reviewed, and a database of references was compiled. In addition to the surface preparation of the steel pipe and the type of coating that is used, the level of cathodic protection (C.P.) reaching the pipe surface and the partial pressure of CO2 in the ground water are important factors. The balance between the level of C.P. reaching the surface and the CO2 partial pressure in the ground water is critical in determining the pH at the steel surface, and hence, whether high-pH SCC, near-neutral-pH SCC, or neither, occurs. Corrosion at pits and other localized sites may be a part of the SCC pre-initiation process. Under ground water conditions that simulate those of near-neutral-pH SCC, hydrogen enters and permeates linepipe steels.
Benefit: The findings of a review on conditions that lead to generation of stress corrosion cracking (SCC) environments is presented in this report. The literature citations have been organized using Reference Manager, a searchable database of references. About 1,600 citations to references available in the literature as well as to industry reports are listed in the Reference Manager, covering all aspects of stress corrosion cracking, including issues relevant to generation of environments that cause SCC, such as coatings. Selected items from the Reference Manager database are listed in the Appendix of this report.
CANMET Materials Technology Laboratory
Need: There are several types of environmentally-assisted cracking that can be of concern to pipeline operators, including hydrogen-induced cracking (HIC), stress-oriented hydrogen-induced cracking (SOHIC), and stress corrosion cracking (SCC), which may be either transgranular or intergranular. This review is concerned with SCC, which usually initiates on the external surface of the pipeline, under the combined influence of stress and ground water or some derivative of the latter.
Result: Current knowledge of the conditions leading to generation of environments that cause stress corrosion cracking (SCC) of high-pressure pipelines was reviewed, and a database of references was compiled. In addition to the surface preparation of the steel pipe and the type of coating that is used, the level of cathodic protection (C.P.) reaching the pipe surface and the partial pressure of CO2 in the ground water are important factors. The balance between the level of C.P. reaching the surface and the CO2 partial pressure in the ground water is critical in determining the pH at the steel surface, and hence, whether high-pH SCC, near-neutral-pH SCC, or neither, occurs. Corrosion at pits and other localized sites may be a part of the SCC pre-initiation process. Under ground water conditions that simulate those of near-neutral-pH SCC, hydrogen enters and permeates linepipe steels.
Benefit: The findings of a review on conditions that lead to generation of stress corrosion cracking (SCC) environments is presented in this report. The literature citations have been organized using Reference Manager, a searchable database of references. About 1,600 citations to references available in the literature as well as to industry reports are listed in the Reference Manager, covering all aspects of stress corrosion cracking, including issues relevant to generation of environments that cause SCC, such as coatings. Selected items from the Reference Manager database are listed in the Appendix of this report.