STEEL Russian patent published in 2009 - IPC C22C38/26 

FIELD: metallurgy.

SUBSTANCE: invention relates to econom-alloyed corrosion-resistant steels, provided for manufacturing of pipes with increased operation life, which are used during building of main and commercial oil-products pipelines. Steel contains carbon, silicon, manganese, chrome, molybdenum, aluminium, rare-earth metals, vanadium, niobium, iron and unavoidable admixtures, at following components correlation, wt %: carbon 0.03 - 0.12, silicon 0.17 - 0.40, manganese 0.40 - 0.70, chrome 0.50 - 1.20, molybdenum 0.15 - 0.30, aluminium not more than 0.06, vanadium 0.04 - 0.10, niobium 0.03 - 0.06, rare-earth metals 0.002 - 0.016, iron and unavoidable admixtures are the rest. In the capacity of unavoidable admixtures it contains sulfur not more than 0.010 wt %, phosphorus not more than 0.018 wt % and hydrogen not more than 0.00025 wt %.

EFFECT: it is increased resistance of steel against sulphide and carbon dioxide corrosion, and resistance against biocorrosion.

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