Steel for high-ductility anti-seismic structure with yield ratio smaller than or equal to 0.70 and production method of steel

Abstract

The invention relates to steel for a high-ductility anti-seismic structure with the yield ratio smaller than or equal to 0.70 and a production method of the steel. The steel consists of chemical components including, by weight, from 0.03 to 0.10% of C, from 0.16 to 0.62% of Si, from 1.00 to 2.20% of Mn, smaller than or equal to 0.010% of P, smaller than or equal to 0.010% of S, from 0.12 to 0.645% of Cu, from 0.12 to 0.64% of Cr, from 0.06 to 0.32% of Mo, from 0.010 to 0.062% of Nb, from 0.12 to 0.38% of Ni and from 0.0015 to 0.020% of Zr or from 0.0010 to 0.020% of RE or a combination of theNi and the Zr, the chemical components meet formulas that Cu+Cr is larger than or equal to 0.60% and smaller than or equal to 1.2%, Pcm is smaller than or equal to 0.24%, and Zr+Re is smaller than orequal to 0.025%. The production method includes steps: smelting and externally refining; protectively pouring in a whole process; heating a casting blank; roughing; precisely rolling; realizing laminar cooling; and naturally cooling to reach the room temperature. Pcm is smaller than or equal to 0.24, the yield ratio (ReL / Rm is larger than or equal to 0.70) is low, safety factors are high, the steel is non-quenched and tempered steel, the steel is delivered in a rolling control state, a production process is simple, and the production method is easy in implementation.

Description

technical field [0001] The invention relates to steel for building structure engineering and a manufacturing method thereof, in particular to steel for high-toughness anti-seismic structures with a yield ratio less than 0.7 and a manufacturing method thereof. Background technique [0002] With the rapid development of the domestic economy, the steel structure industry is becoming a huge market that the domestic and foreign steel industry is optimistic about. In accordance with the requirements of the State Council to develop a circular economy and build a conservation-minded society, high-performance steel should be widely used in steel structure projects to reduce steel consumption, improve the safety factor and service life of steel, improve the efficiency of steel use, and follow the "resources-products-waste The cyclical development process of "materials-renewable resources" can obtain the greatest possible social and economic benefits with as few resources as possible. ...

AI Technical Summary

Problems solved by technology

Its shortcomings: the content of precious alloy elements Ni and Mo is high, and the steel plate must be quenched and tempered, which increases the production cost

[0005] The Chinese patent No. 201010218179.X discloses a hot-rolled steel plate with a tensile strength of 590 MPa and its production method. Its chemical composition is C: 0.05-0.10%, Si: 0.10-0.25%, Mn: 1.10-1.50 %, P: 0.03-0.08%, S ≤ 0.008%, Cr: 0.50-0.80%, Als: 0.015-0.065%, its shortcomings: high P content, low tensile strength level, steel plate thickness is only 2.5-6.0mm

[0006] There are also patent documents with Chinese patent numbers 200910061106.1, 200910012361.7, 200910012360.2 and 200610125365.2, which have disadvantages: steel plates must undergo complicated heat treatment procedures, which increases production costs

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