High-strength weather resisting steel with Cu2-xS dispersed precipitates and manufacturing method thereof

Abstract

The invention relates to high-strength weather resisting steel with Cu2-xS dispersed precipitates, which comprises the following chemical components in percentage by weight: 0.04-0.08% of C, 0.20-0.40% of Si, 0.4-1.0% of Mn, 0.03-0.12% of P, not more than 0.2% of S, 0.01-0.06% of Al, 0.20-0.80% of Cu, 0.40-0.6% of Cr, 0.12-0.40% of Ni, 0.001-0.006% of Ca and the balance of Fe and inevitable impurities. The welding cold crack sensitivity coefficient Pcm is not more than 0.18%. A manufacturing method comprises the following steps of: acceleratedly cooling both sides of a cast belt formed by continuous casting by using a gas and adopting a thin belt continuous casting production technology, wherein the cooling rate is 150-200 DEG C / s; performing the entire double-roller continuous casting process in a closed chamber filled with protective atmosphere; and arranging one to two stands for online hot rolling, wherein the thickness of a finished steel belt reaches 0.6-2 mm. The desulfurization procedure in steel making process can be omitted, and the steel making cost is reduced. The segregation of copper elements is inhibited, meanwhile, a large quantity of dispersed Cu2-xS precipitates can be formed to achieve the effect of dispersion strengthening.

Description

technical field [0001] The invention relates to atmospheric corrosion-resistant steel and a manufacturing method thereof, in particular to a steel with Cu 2-x A high-strength atmospheric corrosion-resistant steel with S dispersed precipitates and a manufacturing method thereof. Background technique [0002] In the traditional process of steel production, copper and sulfur are typical residual elements or inclusion elements in steel. It is very difficult to fully remove copper in the steelmaking process, and it is also very expensive to fully remove sulfur. These all cause the cost of steel products to increase. raised. [0003] In recent years, due to the continuous recycling of scrap steel, the content of residual elements such as copper (Cu) and sulfur (S) in steel has gradually increased. Cu in steel has a lower melting point than the steel matrix, which will cause hot embrittlement on the steel surface. Phenomenon S is a main element that causes hot embrittlement of st...

AI Technical Summary

Problems solved by technology

[0013] (1) In terms of composition: there is no breakthrough in conventional understanding, and the strength of weathering steel can be upgraded by selectively adding alloy elements such as Nb, V, Ti, Mo; at the same time, the requirements for sulfur are mostly strictly controlled, and the steelmaking process cannot be eliminated. desulfurization process;

[0014] (2) In terms of manufacturing methods: thick slab continuous casting + hot continuous rolling process or thin slab continuous casting and rolling process are mostly used. These processes have long process flow, high energy consumption, many unit equipment, high infrastructure cost and high production cost

[0015] (3) In terms of product quality: there are many defects, the yield is low, and most of the atmospheric corrosion-resistant steel contains high phosphorus and copper elements that are easy to segregate. The traditional process is easy to cause phosphorus, copper and other elements due to slow solidification and cooling Localized macrosegregation, resulting in anisotropy of the slab and the appearance of macrocracks

Weathering steel hot-rolled sheets below 1.6mm are rare in the market, mainly because traditional hot rolling is difficult to produce

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