A kind of marine climate-resistant high-toughness bridge steel plate and its production method

Abstract

The invention belongs to the technical field of production of steel for bridges, and particularly relates to a marine-climate-resistant and high-toughness bridge steel plate and a production method thereof. The steel plate is produced from chemical components of raw materials in percentage by mass as follows: 0.041%-0.087% of C, 1.03%-2.00% of Mn, 0.67%-1.43% of Si, less than or equal to 0.007% ofP, less than or equal to 0.003% of S, 0.047%-0.083% of Nb, 0.010%-0.027% of Ti, 0.32%-0.73% of Mo, 0.50%-1.17% of Cr, 0.50%-1.05% of Cu, 2.51%-6.70% of Ni, 0.0021%-0.0073% of Ca, 0.08%-0.31% of Sb and the balance of Fe and inevitable impurities. According to the production method of the steel plate, the number and the shape of inclusions in the steel are controlled by the aid of Ca, the effects of inhibiting the corrosion reaction and improving the corrosion resistance are realized, proper amounts of Sb, Cu, Ni, Cr and Mo are added, the corrosion resistance of the steel is improved, and the produced steel plate is high in strength, good in shock resistance, excellent in marine atmosphere corrosion resistance and excellent in low-temperature toughness.

Description

technical field [0001] The invention belongs to the technical field of steel production for bridges, and in particular relates to a marine climate-resistant high-toughness bridge steel plate and a production method thereof. Background technique [0002] With the vigorous development of high-speed railway and expressway traffic in China, and the gradual implementation of the coastal eight-vertical and eight-horizontal railway planning scheme, the long-span road-rail bridge has become a key node project in the coastal high-speed railway traffic network. The long-span road-rail dual-purpose sea-crossing bridge requires the steel plate to have excellent resistance to marine weather corrosion, and also puts forward new requirements for high strength, high toughness, and seismic performance. [0003] Patent CN201610539721.9 discloses a marine weather-resistant and corrosion-resistant steel and its production method. Its chemical composition (by weight percentage) is: C: ≤0.06%, Si...

AI Technical Summary

Problems solved by technology

The steel in this document is mainly developed for offshore platforms and produced by quenching and tempering process. The steel only contains a small amount of Cu and Ni elements without adding other corrosion-resistant elements, which is not conducive to the marine corrosion resistance of the steel plate. In addition, the steel is produced by quenching and tempering process. Its production cost is higher

[0006] The deficiencies in the above patents: 1) Some patented steel grades are not high in strength; 2) The steel plates do not have weather resistance at the same time; 3) Some patented steels are produced by hot rolling or quenched and tempered heat treatment, and the specification range of the steel plate is narrow or the production process long, expensive

[0009] However, in order to ensure the weather resistance of steel materials, more alloying elements such as Si, Cu, Cr, Ni, and Mo are usually added. Usually these elements are solid solution strengthening elements, which increase the hardness of the ferrite matrix and reduce the plasticity. Significantly delay the pro-eutectoid ferrite transformation, make it easier to form martensite in the heat-affected zone during the welding process, and cause welding cracks. structure, to obtain the matching of high strength, high toughness and high weather resistance

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