690MPa-stage anti-seismic fire-proof weather-proof building structure steel and preparing method thereof

Abstract

The invention discloses 690MPa-stage anti-seismic fire-proof weather-proof building structure steel and a preparing method thereof. The steel comprises, by weight percent, 0.05 to 0.10% of C, 0.01 to0.30% of Si, 1.0 to 1.4% of Mn, 0 to 0.01% of P, 0 to 0.002% of S, 0.01 to 0.5% of Mo, 0.01 to 0.05% of Nb, 0.01 to 0.03% of Ti, 0 to 0.06% of V, 0.4 to 1.0% of Cr, 0.3 to 0.4% of Cu, 0.3 to 0.4% of Ni, 0 to 0.003% of B, 0.001 to 0.08% of N and the balance Fe and inevitable impurities. The preparing method comprises the steps of steel making, refining, continuous casting, steel blank heating, two-stage controlled rolling and controlled cooling and heat treatment. On the premise that the use property meets GB / T 19879 building structure steel plate needs, the yield strength is larger than or equal to 706 MPa, the yield ratio is smaller than or equal to 0.849, DNH coefficient is larger than or equal to 6.5%, at the temperature of 600 DEG C, heat preservation is carried out for one to three hours, the yield strength is not lower than 2 / 3 at the room temperature, meanwhile, the anti-seismic fire-proof weather-proof needs are met, and the property is excellent.

Description

[0001] Technical field: [0002] The invention belongs to the technical field of steel for building structures, and in particular relates to 690MPa grade earthquake-resistant, fire-resistant and weather-resistant steel for building structures and a preparation method thereof. [0003] Background technique: [0004] According to the analysis of earthquake experts, casualties in earthquakes are generally caused by house collapses. For example, in the 2008 Munchuan Earthquake, due to the structural system of most houses being brick-concrete structure and concrete structure, the materials are heavy and have poor elastic-plastic properties, a large number of houses will collapse completely in an instant, which brings great difficulties to self-rescue and search-and-rescue work. great difficulty. Due to the high strength and good earthquake resistance of the steel structure, it can be manufactured in a factory, installed on site, has a short construction period, can be reused, reduc...

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Problems solved by technology

[0006] In terms of many key varieties, it is still unable to meet the needs of the rapid development of the national economy, and has to rely on imports to a large extent.

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