The Canadian Energy Pipeline Association Stress Corrosion Cracking Database

1998 ◽  
Author(s):  
Bruce R. Dupuis
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Data Entry ◽  
Corrosion Cracking ◽  
Laboratory Research ◽  
Data Repository ◽  
Detailed Data ◽  
Current Version ◽  
Industry Standard ◽  
Operational Failures

The SCC (stress corrosion cracking) database was initiated by the CEPA (Canadian Energy Pipeline Association) SCC Working. The current generation of the database has a broad scope, containing detailed data for each and every colony and its associated environmental conditions. The database also includes corrosion and dents amongst other integrity concerns to identify any correlation with SCC and provide a common industry data format to investigate these other integrity issues. The intent of the current version of the database is to provide for the most detailed data entry that one could typically capture at an investigative dig. With the wide acceptance of the current version the CEPA database it is evolving into the industry standard for investigative excavation data. The initial trending results are based on the dataset generated by CEPA member companies, which represents over a thousand investigative excavations. The trend results should only be interpreted broadly at this time, although they do generally support industry’s understanding of SCC. The development and implementation of the CEPA SCC database is premised on the belief, developed through extensive field investigations and laboratory research, that SCC is not a random development, but it initiates and grows at specific locations susceptible to SCC. It is further premised on the belief that such susceptible sites can be generally located by appropriate prioritization techniques. Thus, the objective of the database is to explore correlation among the various operational and environmental variables to improve the current understanding of how to locate SCC, and in particular ‘significant’ SCC, in order that measures can be taken to prevent operational failures and enhance the safety of Canadian pipelines. The need for an industry database regarding SCC was identified by the CEPA SCC working group shortly after its formation 1994. It was apparent that the various companies were collecting the field data from investigative excavations in significantly different formats, only some of which were electronic. The need for a common data structure and data repository to facilitate trending was reinforced numerous times at the Banff Conferences and by the NEB during its inquiry into SCC in 1995/96.

Studying Stress Corrosion Cracking Crack Initiation in Pipeline Steels in a Near-Neutral pH Environment: The Role of Hydrotesting

CORROSION ◽  
10.5006/3492 ◽  
2020 ◽  
Vol 76 (11) ◽  
Author(s):  
Zeynab Shirband ◽  
Jing-Li Luo ◽  
Reginald Eadie ◽  
Weixing Chen
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Pressures ◽  
Initial Study ◽  
Corrosion Cracking ◽  
Pressure Cycling ◽  
Small Cracks ◽  
Crack Transition ◽  
Operational Failures

Hydrostatic testing, or hydrotesting, has been widely used as a stress corrosion cracking management method in the pipeline industry, particularly in gas pipelines. Although the technique has been very useful in the prevention of operational failures, it is known that these high pressures can produce significant plastic deformation around stress concentrators, such as pits and other surface flaws, that might be present. This plasticity can temporarily retard long, well-developed cracks; however, the effect of this plasticity on growth of very small cracks has not previously been studied. In this work, a long-term test was conducted to simulate real pipeline pressure cycling conditions by the application of occasional hydrotesting loads on steel samples. Crack initiations from pits were compared between specimens undergoing no hydrotesting load (control specimens) and those that underwent three hydrotest cycles during the test. The results showed that pit-to-crack transition was enhanced by the application of three hydrotesting loads. Seventy percent more cracks were found to have grown beyond ferrite grain boundaries in the hydrotested specimens. This initial study indicated substantial differences between small crack formation with and without hydrotesting. These differences predict significantly higher short crack growth in the hydrotested samples. Further study is necessary to further delineate these effects.

Methanol-Induced Axial Stress Corrosion Cracking in a Northern Canadian Liquids Pipeline

2014 ◽  
Author(s):  
Barbara N. Padgett ◽  
Mohamed R. Chebaro ◽  
David M. Norfleet ◽  
John A. Beavers ◽  
Scott D. Ironside
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Axial Stress ◽  
Internal Surface ◽  
Corrosion Cracking ◽  
Laboratory Research ◽  
Published Data ◽  
Contributing Factors ◽  
Pipeline Steels ◽  
Oil Pipeline

Three in-service leaks on a crude oil pipeline operating in Canada were investigated to identify their metallurgical cause(s). The releases were found to be associated with cracks originating from the internal surface of the pipeline. Further similarities between the releases included: (1) the axial directionality of the cracks, (2) the short crack length, (3) the crack location adjacent to girth welds, (4) the circumferential location of the cracks and (5) the intergranular crack morphologies. A comprehensive metallurgical investigation concluded that the likely crack-initiating mechanism was methanol-induced stress corrosion cracking (SCC). While this SCC mechanism is extremely rare in buried petroleum pipelines, all other plausible causes were considered and eliminated. Methanol-induced SCC, similar to other forms of SCC, requires three contributing factors: (1) a susceptible material, (2) a corrosive environment and (3) sufficient tensile stresses. Although much research has been performed on the effects of ethanol on pipeline steels, published data on the effects of methanol is very scarce. A laboratory research program using slow strain rate (SSR) testing was initiated to determine if pipeline steels are susceptible to methanol-induced SCC and identify the conditions necessary to reproduce it in a laboratory environment. This paper outlines the major findings from this program.

AMBRONZE 413

Alloy Digest ◽  
1969 ◽  
Vol 18 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Stress Corrosion Cracking ◽  
Electrical Contact ◽  
Heat Treating ◽  
Corrosion Cracking ◽  
Tin Bronze

Abstract AMBRONZE 413 is a copper-tin bronze recommended for plater's plates and electrical contact springs. It is relatively immune to stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-201. Producer or source: Anaconda American Brass Company.

NICROFER 5716 HMoW

Alloy Digest ◽  
1985 ◽  
Vol 34 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Stress Corrosion Cracking ◽  
Crevice Corrosion ◽  
Corrosion Cracking ◽  
Low Carbon ◽  
Nickel Chromium ◽  
Corrosion Pitting

Abstract NICROFER 5716 HMoW is a nickel-chromium-molybdenum alloy with tungsten and extremely low carbon and silicon contents. It has excellent resistance to crevice corrosion, pitting and stress-corrosion cracking. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: Ni-324. Producer or source: Vereingte Deutsche Metallwerke AG.

NAS 825

Alloy Digest ◽  
2012 ◽  
Vol 61 (2) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Nickel Alloy ◽  
Stress Corrosion Cracking ◽  
Chloride Ion ◽  
Heat Treating ◽  
Corrosion Cracking ◽  
Corrosion Resistant

Abstract NAS 825 is a corrosion-resistant nickel alloy that has resistance to both oxidizing and reducing environments, and with 42% nickel, the alloy is very resistant to chloride-ion stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-694. Producer or source: Nippon Yakin Kogyo Company Ltd.

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