Anti-large-deformation pipe line steel prepared by thermal treatment method and preparation method thereof

Abstract

The invention discloses anti-large-deformation pipe line steel prepared by a thermal treatment method and a preparation method thereof. The steel comprises the following chemical components of: not less than 0.02% and not greater than 0.12% of C, not less than 0.5% and not greater than 2.0% of Mn, not more than 0.25% of Si, not more than 0.02% of P, not more than 0.01% of S, not more than 0.11% of Nb, not more than 0.08% of V, not more than 0.05% of Ti, not more than 0.06% of Al, not more than 0.012% of N, not more than 0.50% of Cu, not more than 0.60% of Cr, not more than 0.50% of Mo, not more than 0.60% of Ni, not more than 0.005% of B, not more than 0.01% of Ca and the balance of Fe and inevitable impurities, wherein the CEIIW is not less than 0.3% and not greater than 0.45%, and the CEPcm is not more than 0.2%. The preparation method comprises the following steps of: heating steel at 700-950 DEG C in a thermal treatment furnace, maintaining the temperature for 6-15 min, cooling with the rate of 1-400 DEG C / s to room temperature, and simultaneously tempering from room temperature to 500 DEG C to obtain steel with ferrite as a first phase and bainite, martensite, degenerate perlite or any mixture thereof as a second phase. The steel has the advantages of high tensile strength, low yield strength, low yield ratio, high uniform elongation rate and high strain hardening exponent, thereby having good toughness and deformation performance.

Description

technical field [0001] The invention belongs to the field of metallurgy and relates to a pipeline steel, in particular to a large deformation resistant pipeline steel prepared by a heat treatment method and a preparation method thereof. Background technique [0002] As oil and gas transmission pipelines continue to extend to permafrost or earthquake areas, the demand for large-deformation pipeline steel pipes has further increased. When laying pipelines in these areas, the movement of the ground may cause large strains on the steel pipes. Therefore, the pipeline steel used must have the deformation ability to prevent local bending and fracture of pipeline butt girth welds. The way to improve the deformation resistance of steel pipes used in oil and gas pipelines is to increase the wall thickness of steel pipes, but this will inevitably increase the construction cost of the pipes. Using steel pipes with large deformation resistance can obtain high deformation resistance of st...

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Problems solved by technology

[0004] At present, dual-phase pipeline steel is produced by rolling, and there is no report on the production of dual-phase pipeline steel by heat treatment process

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