High-tensile quenched and tempered steel plate for large-thickness structures and production method thereof

Abstract

The invention discloses a high-tensile quenched and tempered steel plate for large-thickness structures and a production method thereof, wherein the high-tensile quenched and tempered steel plate comprises the following chemical compositions in percentage by weight: less than or equal to 0.19% of C, less than or equal to 0.50% of Si, 1.00-1.60% of Mn, less than or equal to 0.015% of P, less than or equal to 0.003% of S, less than or equal to 0.20% of microalloying elements (Nb+V+Ti+Ni), less than or equal to 0.050% of Als, and the balance of Fe and residual elements. By reasonably taking a chemical composition design on composite multicomponent microalloying elements and adopting an LF+VD (ladle refining + vacuum degassing)process, the purity of the steel plate is ensured, and the sum of levels of various inclusions is not more than 3.0; and by utilizing a thermo mechanical control process and adopting normalizing treatment, the grain fineness number of the steel plate reaches level 9.0-10.0; by means of the effective implementation of the measures, the extra-thick steel plates (thickness: greater than or equal to 100mm) for high-rise buildings with guaranteed flaw detection and mechanical properties are produced successfully.

Description

technical field [0001] The invention relates to the technical field of improving industrial steelmaking performance, in particular to a high-strength quenched and tempered steel plate for large-thickness structures and a production method thereof. Background technique [0002] At present, steel plates with the same or similar properties and grades as high-strength steel plates have been used abroad, but they have not been used in large-scale applications in China for structures such as pressure vessels, offshore platforms, and bridges. The application of this kind of steel in China has always relied on foreign imports. The domestic wide and thick plates have not been produced. If imported, not only the price is expensive, but also the purchase cycle is long, which cannot guarantee the normal progress of the project. Contents of the invention [0003] The object of the present invention is to provide a high-strength quenched and tempered steel plate for large-thickness stru...

AI Technical Summary

Problems solved by technology

The application of this kind of steel in China has always relied on foreign imports. The domestic wide and thick plates have never been produced. If imported, not only the price is expensive, but also the purchase cycle is long, which cannot guarantee the normal progress of the project.

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