225MPa earthquake-proof low yield strength steel and manufacturing method thereof

Abstract

The invention provides earthquake-proof low yield strength steel and steel plate, characterized by containing the components in percentage by weight: at most 0.05 percent of C, at most 0.10 percent of Si, at most 1.0 percent of Mn, at most 0.01 percent of P, at most 0.006 percent of S, 0.01-0.05 percent of Al, at most 0.005 percent of N, 0.01-0.10 percent of Ti and the balance of Fe and unavoidable impurities. The invention also provides a manufacturing method of the steel plate, comprising the working procedures of heating steel billets, hot rolling and heat treatment after rolling. The steel is designed by adopting the component of ultra-low C, low Si and Mn and adding one or more than one of Ti, Nb or V, is produced by adopting a way of hot rolling at high temperature or hot rolling and normalizing, and has simple production process and lower cost. The steel has excellent impact resistance and welding property, low cycle fatigue property and very high elongation in addition to have low yield strength and is mainly used for the earthquake-proof design of building structures.

Description

technical field [0001] The invention relates to the field of iron and steel materials, in particular, the invention relates to a low-yield-strength steel for earthquake resistance. Background technique [0002] With the development of building anti-seismic technology, energy dissipation anti-seismic technology has become the development direction of anti-seismic design of building structures due to its good anti-seismic effect. The low yield point steel used to make building energy dissipation dampers has become a new type of anti-seismic steel. Prior to the present invention, there have been many invention patents on low-yield-point steel for building anti-seismic use, such as the patent document JP05214442A disclosed in 1993 (production of structural steel with low yield strength and high elongation), and the patent document JP06235042A disclosed in 1994 (super low yield point steel), patent documents JP10001741A (low yield point structural steel with high elongation and i...

AI Technical Summary

Problems solved by technology

The addition of these alloying elements increases the difficulty of steelmaking and increases manufacturing costs

In addition, the steel involved in the patent document JP2004339548 requires the cooling rate to be lower than 2°C / s in the range of 400-700°C after rolling, which prolongs the production cycle of the steel plate

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