A kind of yield 345mpa grade refractory steel plate and its production method

Abstract

The present invention discloses a yield 345 MPa grade fire-resistant steel plate and a production method thereof. The production method comprises the steps of heating, rolling, and tempering. In the step of rolling, a recrystallization zone plus non-recrystallization zone two-stage conditioned rolling process is adopted. The steel plate is composed of the following chemical components in percentage by weight: 0.10-0.12% of C, 0.20-0.40% of Si, 1.43-1.53% of Mn, less than or equal to 0.008% of P, less than or equal to 0.003% of S, 0.15-0.25% of Mo, 0.020-0.030% of Nb, 0.020-0.50% of Al, 0.020-0.030% of V, and the balance of Fe and inevitable impurities. Low C is determined in the chemical component design of the steel plate in the method to ensure favorable weldability of the steel plate; the microalloying design of Nb and V, accompanied with such alloy elements as Mo, is adopted to ensure matching of strength and toughness and high temperature resistance of the steel plate; and a TMCP plus tempering process is adopted to obtain a composite structure of bainite and ferrite. The method provided by the present invention is used to produce the steel plate through the thermo mechanical control processing plus tempering process; the obtained yield 345 MPa grade TMCP plus tempering type fire-resistant steel plate has the characteristics of low carbon equivalent and crack sensitivity index, low yield ratio, favorable low temperature impact strength, good weldability, and the like.

Description

technical field [0001] The invention relates to a fire-resistant steel plate and a production method thereof, in particular to a 345MPa-yield fire-resistant steel plate and a production method thereof. Background technique [0002] With the continuous emergence of large-scale buildings and high-rise buildings with steel structures at home and abroad, the fire protection process design of steel structures has been widely valued by people in the world. The fire protection process design of building steel structures has become one of the necessary measures to ensure building safety. When ordinary building steel is heated, its strength and bearing capacity decrease rapidly, which cannot meet the design requirements. In order to improve the fire-resistant ability of buildings built with ordinary construction steel, measures such as spraying fire-resistant coatings or covering fire-proof boards must be taken, and the use of fire-resistant steel can reduce or omit fire-resistant co...

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Problems solved by technology

When ordinary building steel is heated, its strength and bearing capacity decrease rapidly, which cannot meet the design requirements

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