Hydrogen sulfide corrosion resistant pipeline steel mainly used to manufacture and transport sour gas pipeline. With the improvement of the delivery pressure and reduce the gas from the viewpoint of the cost of desulfurization, sometimes without desulfurization of the gas pipeline circumstances, so that such pipelines have to use the pipeline corrosion resistance to hydrogen sulfide.
Hydrogen sulfide corrosion resistant steel for oil pipeline and gas pipeline is the most difficult to produce a type of steel, because of its purity of molten steel, billet segregation controls and controlled rolling and cooling requirements of high traditional metallurgical processes can not meet the requirements .
Usually in the acid gas environment, pipeline failure reasons are two: one is the sulfide stress corrosion cracking, referred to SSC. The defect is in the high strength steel surface and the internal stress and hydrogen sulfide corrosion under the action of the medium together with the stress direction perpendicular wall cracks. In the pipeline in service process, the high-grade steel pipeline prone to SSC.
Another one is hydrogen induced cracking, referred to HIC. The cracks due to the high concentration of hydrogen sulfide gas environment into the steel corrosion inside the hydrogen produced in the vicinity of inclusions and segregation resulting enrichment of the surface parallel to the wall cracking. HIC occurs mainly in low-, medium-strength steel planted.
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