High strain hot rolled steel plate for L485M offshore pipeline pipe and manufacturing method thereof

Abstract

The invention provides a high strain hot rolled steel plate for an L485M offshore pipeline pipe and a manufacturing method thereof. The steel plate is prepared from the following components in percentage by weight: 0.02 to 0.08 percent of C, 0.10 to 0.40 percent of Si, 1.40 to 1.80 percent of Mn, 0.02 to 0.08 percent of Nb, 0.01 to 0.05 percent of V, 0.01 to 0.04 percent of Ti, 0.025 to 0.045 percent of Al, less than or equal to 0.010 percent of P, less than or equal to 0.005 percent of S, 0.10 to 0.50 percent of Cu, 0.02 to 0.30 percent of Mo, 0.06 to 0.45 percent of Cr, 0.10 to 0.50 percentof Ni, and the balance of Fe and unavoidable impurity elements. The manufacturing method comprises the steps of smelting molten steel, refining out of a furnace, casting, re-heating a plate blank, performing controlled rolling, performing controlled cooling, and performing air cooling to room temperature; the longitudinal mechanical properties of the steel plate produced by applying the manufacturing method are that the UEL (Uniform Elongation of Deformation) is greater than or equal to 10 percent, the yield strength Rt 0.5 is 400 to 550 MPa, the tensile strength Rm is 550 to 700 MPa, and theyield-to-strength ratio Rt0.5/Rm of the steel plate is 0.70 to 0.80.

Description

technical field [0001] The invention belongs to the field of metal materials, and in particular relates to a high-strain hot-rolled steel plate for L485M marine line pipe and a manufacturing method thereof. Background technique [0002] With the rapid development of the global economy, the consumption of oil and gas resources in various countries has increased sharply, and land resources have been gradually depleted, resulting in the focus of oil and gas exploitation shifting to the sea. As a country with a vast territorial sea, in order to safely and effectively utilize submarine oil and gas resources, especially deep-sea oil and gas resources, it is of great significance to develop steel materials for submarine oil and gas transportation. [0003] As we all know, the movement of ocean currents is complex and changeable, and the geological conditions of the seabed are harsh. Oil and gas pipelines serving under such working conditions need to have the characteristics of high...

AI Technical Summary

Problems solved by technology

[0008] The object of the present invention is to overcome the above-mentioned problems and deficiencies and provide a high-strain hot-rolled steel plate for L485M ocean line pipe and its manufacturing method. The steel plate produced by the present invention can ensure the safety of the oil and gas transmission line pipe laid in the marine environment, and has a large wall Thick, high-strain characteristics, while overcoming the shortcomings of the existing technology such as complex production process, high equipment capacity requirements and inability to directly assemble production

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