Pipeline steel excellent in acid corrosion resistance on seabed and production method

Abstract

The invention discloses pipeline steel excellent in acid corrosion resistance on the seabed. The pipeline steel comprises, by weight, 0.020-0.050% of C, 0.10-0.30% of Si, 0.50-1.10% of Mn, 0.012% of P or less, 0.0015% of S or less, 0-0.20% of Cu, 0-0.30% of Cr, 0-0.20% of Ni, 0-0.25% of Mo, 0.030-0.055% of Nb, 0.020-0.050% of V, 0.010-0.025% of Ti, 0.010-0.050% of Al and 0.008% of N or less. A production method comprises the steps of heating after continuous casting and blank forming, rough rolling, precise rolling, cooling, reeling and cooling to indoor temperature. By means of the pipeline steel and the production method, an ideal complex-phase structure containing ultra-fine grain polygonal ferrite and a small number of methyl acrylate (MA) components which are distributed dispersively can be obtained, the Rt0.5 is equal to or higher than 485 MPa, the Rm is equal to or higher than 570 MPa, -20 DEG C KV2 is equal to or higher than 250 J, and -15 DEG C DWTT SA is equal to or higher than 85%. A hydrogen induced crack j (HICj) test and a sulfide stress corrosion cracking (SSCC) test indicate that no fracture or crack occurs.

Description

technical field [0001] The invention relates to a pipeline steel and a production method, in particular to a pipeline steel with excellent seabed acid corrosion resistance and a production method. Background technique [0002] With the gradual depletion of land oil and gas resources, new resource exploitation extends to areas with harsh geological conditions such as oceans, polar regions, and acidic conditions. At present, it has been proven that the world's offshore oil resources account for 34% of the world's total oil resources, and the annual production of offshore natural gas has reached 32% of the world's total annual natural gas production. More than 100 countries around the world are conducting offshore oil exploration, of which Most countries have started the construction of submarine pipelines and oil and gas exploration. Therefore, the importance of the development and application of steel for submarine pipelines has become increasingly prominent. [0003] Submar...

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Problems solved by technology

[0007] The purpose of the present invention is in order to overcome the anti-CO 2 Insufficient capacity, high manufacturing cost, difficult production process control and other deficiencies, and provide a R t0.5 ≥485MPa,R m ≥570MPa, R t0.5 / R m ≤0.90,A 50mm ≥30%, -20℃KV 2 ≥250J, -15°C DWTTSA≥85%, and excellent resistance to hydrogen sulfide corrosion, seabed pipeline steel with excellent corrosion resistance and production method

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