290 MPa-grade anti-seismic low-yield strength steel and manufacturing method thereof

Abstract

The invention discloses 290 MPa-grade anti-seismic low-yield strength steel and a manufacturing method thereof. The steel comprises the following components of, in percentage by weight, 0.06%-0.12% ofC, 0.1%-0.3% of Si, 0.9%-1.2% of Mn, less than or equal to 0.026% of P, less than or equal to 0.016% of S, less than or equal to 0.0060% of N, and the balance Fe and inevitable impurities. Through simple chemical component design, two-stage rolling and cooling processes, a low-yield strength steel plate can be obtained, wherein the the thickness of the steel plate is less than or equal to 100 mm,and the yield strength YP of the steel plate is 270-310 Mpa, the low-yield strength steel plate is simple in component, does not contain expensive alloy elements, and is relatively low in manufacturing cost. The steel has good impact and welding performance and low-cycle fatigue performance, the elongation rate is very high, and the steel is mainly used for anti-seismic design of a building structure.

Description

technical field [0001] The invention relates to a low yield strength steel and a manufacturing method thereof, in particular to a 290Mpa earthquake-resistant low yield strength steel and a manufacturing method thereof. Background technique [0002] At present, low yield point steels on the market can be divided into three types according to their grades: 100MPa, 160MPa, and 225MPa. The following are related patents: [0003] The patents with publication numbers "CN101845589" and "JP10324918A" both disclose a steel plate with an extremely low yield point and its manufacturing method, and its yield strength is about 140MPa. The inventions all add one or more of N, Ti, and Nb on the basis of low C-Si-Mn, and contain B element, but the addition of B not only increases the manufacturing cost of the steel plate, but also increases the difficulty of smelting. [0004] The patent with the publication number CN101775536A discloses a 225MPa-level earthquake-resistant low-yield-streng...

AI Technical Summary

Problems solved by technology

The inventions all add one or more of N, Ti, and Nb on the basis of low C-Si-Mn, and contain B element, but the addition of B not only increases the manufacturing cost of the steel plate, but also increases the difficulty of smelting

[0004] The patent with the publication number CN101775536A discloses a 225MPa-level earthquake-resistant low-yield-strength steel and its manufacturing method. The invention adopts a low-C, low-Si-Mn composition design, and chooses to add one of Ti, Nb or V or multiple, the design uses precious metal elements and is costly

[0005] The patent with the publication number CN101781736 discloses a kind of earthquake-resistant building steel with a yield strength of 225 MPa and its production method. The invention adopts a low C, low Si-Mn composition design, and adds metal elements such as Re and Mg. The design scheme adds The alloy smelting is difficult, the process is difficult to control, and the follow-up heat treatment takes a long time, which increases the production cycle and cost

[0006] The patent with the publication number CN101392350 discloses a steel plate with an extremely low yield point and its manufacturing method. The invention adopts a low C-Si-Mn composition design and adds microalloying elements such as Nb, V, Ti, etc., and its yield strength is 235MPa or so, the composition is designed to use precious metals at high cost

[0007] And there is still no 290Mpa grade earthquake-resistant low-yield-strength steel to meet market demand

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