High-strength high dampness and heat sea atmospheric environment resistant weathering resistant steel and preparing method

Abstract

The invention relates to high-strength high dampness and heat sea atmospheric environment resistant weathering resistant steel and a preparing method, and belongs to the technical field of weathering resistant steel. The steel comprises, by weight, 0.01%-0.03% of C, 0.30%-0.50% of Si, 0.60%-0.80% of Mn, 0.90%-1.10% of Cu, 2.80%-3.20% of Ni, 0.20%-0.40% of Mo, 0.25%-0.35% of Sn, 0.05%-0.10% of Sb, not larger than 0.03% of Cr, not larger than 0.02% of Nb, not larger than 0.01% of P, not larger than 0.01% of S, 0.03%-0.05% of RE and the balance Fe. On the basis of a Cu-Ni-Mo alloy system, the Sn, the Sb, the Nb, the RE and other microalloy elements are added, and the Cr content in the weathering resistant steel is greatly reduced. A steel ingot meeting the composition design scope is smelted through a vacuum induction furnace, through the follow-up forging and hot rolling, the weathering resistant steel with the strength of extension larger than or equal to 750 MPa, the yield strength larger than or equal to 650 MPa and the ductility larger than or equal to 15% is finally obtained; the corrosion resistance is reduced by more than 30% compared with a Q450NQR1 traditional weathering resistant steel; and the high-strength high dampness and heat sea atmospheric environment resistant weathering resistant steel is prepared and has the excellent mechanical property.

Description

technical field [0001] The invention belongs to the technical field of weathering steel, and in particular relates to a high-strength, high-humidity and heat-resistant weathering steel for marine and atmospheric environments and a preparation method thereof. The weathering steel has mechanical properties satisfying tensile strength ≥ 750 MPa, yield strength ≥ 650 MPa, and elongation ≥ 15 %, and has excellent resistance to high humidity and heat marine atmospheric environment performance. Background technique [0002] The 21st century is the century of the ocean. The development of marine engineering equipment and the construction of marine engineering are important contents of promoting and implementing the national marine strategy. Since the beginning of the new century, my country's offshore engineering equipment manufacturing industry has made great progress, especially offshore oil and gas development equipment has a good development foundation, but the ensuing problem o...

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Problems solved by technology

However, there is still a lack of domestic and foreign research on the weathering steel used in high-humidity and hot marine atmospheric environments like the South China Sea. Although the 3Ni advanced weathering steel developed by Japan has been proved to have good corrosion resistance in its coastal exposure test, the South China Sea is in latitude. In addition, its applicability has been questioned due to the harsh high-humidity and heat marine environment. Therefore, it is imperative to independently develop weathering steel suitable for the high-humidity and heat marine and atmospheric environment of the South China Sea.

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