Magnesium-containing X65 pipeline steel with good acid resistance and production method

Abstract

The invention provides magnesium-containing X65 pipeline steel with good acid resistance. The magnesium-containing X65 pipeline steel is prepared from the components in percentage by weight: 0.03-0.05% of C, 0.17-0.20% of Si, 0.40-0.70% of Mn, 0.12-0.15% of Ni, 0.45-0.48% of Cr, 0.10-0.15% of Mo, 0.002-0.004% of Mg, 0.06-0.09% of Nb, 0.01-0.02% of Ti, less than or equal to 0.008% of P, and less than or equal to 0.010% of S. A production method comprises the steps that casting billet is carried out after converter smelting and Mg vacuum treatment; the casting billet is heated; roughing is carried out; finish rolling is carried out; laminar cooling is carried out; and reeling is carried out. Under the premise of ensuring Rt 0.5 is 420-440 MPa, Rm is 480-500 MPa, and Rt 0.5 / Rm is less than orequal to 0.90, the elongation after fracture A50mm is greater than or equal to 20%, -20DEG C impact energy KV2 is greater than or equal to 200J, a shearing surface ratio DWTT SA of a -15 DEG C fracture is greater than 90%, a hardness value HV10 is less than or equal to 180, in a NACE A solution, the hydrogen-induced crack sensitivity CLR, CTR and CSR do not exceed 0.05%, and sulfide stress cracking cannot happen under the 0.9 stress loading rate.

Description

technical field [0001] The invention relates to a pipeline steel and a production method, in particular to a magnesium-containing X65 acid-resistant pipeline steel and a production method. Background technique [0002] With the development of my country's economy and society, the demand for oil and gas resources is huge, and the country is vigorously building oil and gas pipeline networks. However, oil and gas resources are often rich in H 2 In acidic media such as S, pipeline steel will interact with H in the process of transporting oil and gas 2 The S phase contacts and reacts, hydrogen-induced cracking (HIC) and hydrogen sulfide stress corrosion cracking (SSCC) occur, which eventually lead to the failure of pipeline steel, resulting in large economic losses and environmental pollution. In order to ensure the reliability of my country's oil and gas pipeline network, for the transmission of H 2 Sour oil and gas pipelines such as S must use acid-resistant pipeline steel. ...

AI Technical Summary

Problems solved by technology

Therefore, the existing composition system is not conducive to the HIC and SSCC resistance of pipeline steel

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