Evaluation of high steel grade linepipes for sour service with special corrosion testing
- Dalmine SpA (Italy)
The pipeline steels operating in sour environments with presence in many cases of water and other corrosive agents, are subject to three specific corrosion mechanisms typically caused by wet hydrogen sulfide: HIC (Hydrogen Induced Cracking); SSCC (Sulfide Stress Corrosion Cracking); SOHIC (Stress Oriented Hydrogen Induced Cracking). NACE standards TM-01-77 and TM-02-84 show the basic method to evaluate the pipeline steels susceptibility to the corrosion effects by wet hydrogen sulfide. The behavior of the pipeline steels is strictly connected with hydrogen sulfide concentration, pH, temperature, carbon dioxide and water content, flow rate and the quality of the pipeline steel (chemistry, mechanical properties, microstructure, cleanness, morphology and distribution of the inclusions, surface conditions, residual stresses, etc.). Extensive studies are in progress to develop new carbon microalloyed steels for pipelines to meet new requirements due to the higher corrosive environments, together with high mechanical properties at elevated temperatures (until 200 C), good toughness at low temperatures, good strain aging properties. In the same time it appears more frequently, in the specification of the customers and users, the requirement, in combination with the standard NACE tests, for specific and well recognized corrosion laboratory tests in order to evaluate more properly the material behavior. These new tests are based on methods utilizing a sample of a full circumferential ring of linepipe (Full Ring Test). In this paper some experiences, for seamless linepipe steels are described and the results are compared with standard NACE tests.
- OSTI ID:
- 350224
- Report Number(s):
- CONF-980316-; TRN: IM9925%%572
- Resource Relation:
- Conference: Corrosion `98, San Diego, CA (United States), 22-27 Mar 1998; Other Information: PBD: 1998; Related Information: Is Part Of Corrosion `98: 53. annual conference and exposition, proceedings; PB: [6600] p.
- Country of Publication:
- United States
- Language:
- English
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