Hot-rolled high-strength low-nickel-copper ratio thick gauge weathering steel and production method thereof

Abstract

The invention discloses hot-rolled heavy gauge weathering resistant steel high in strength and low in nickel to copper ratio. The hot-rolled heavy gauge weathering resistant steel is prepared from the following chemical components in percentage by mass: 0.055-0.065% of C, 0.56-0.64% of Si, 0.55-0.65% of Mn, 0.022-0.030% of P, less than or equal to 0.005% of S, 0.15-0.19% of Cu, 1.05-1.25% of Cr, 0.05-0.09% of Ni, 0.052-0.058% of Nb, 0.125-0.135% of Ti and the balance of Fe and inevitable impurities, wherein the nickel to copper ratio is smaller than or equal to 0.45. The invention also discloses a method for producing the hot-rolled heavy gauge weathering resistant steel high in strength and low in nickel to copper ratio. According to the hot-rolled heavy gauge weathering resistant steel high in strength and low in nickel to copper ratio and the production method of the steel, the low-carbon low-manganese / niobium / titanium microalloyed component system low in nickel to copper ratio is adopted, and the precipitation strengthening and refined crystalline strengthening effects of Nb and Ti are developed thoroughly by controlled rolling and ultra-fast cooling processes, and therefore, the thickness specification of the hot-rolled high-strength weathering resistant steel is greatly expanded and the hot-rolled high-strength weathering resistant steel excellent in comprehensive mechanical properties can be obtained.

Description

technical field [0001] The invention relates to the technical field of steel production, in particular to a hot-rolled high-strength low-nickel-copper specific thickness specification weathering steel and a production method thereof. Background technique [0002] Weathering steel, also known as atmospheric corrosion-resistant steel, is based on carbon-manganese steel by adding a certain amount of Cu, Cr, Ni and other elements to obtain excellent atmospheric corrosion resistance, and the longer the time, the better the corrosion resistance, and is widely used It is used in steel structure manufacturing fields such as buildings, bridges, containers, and railway vehicles. The existing 700MPa high-strength weathering steel does not adopt the design idea of ​​low nickel-copper ratio, and in order to ensure the mechanical properties, the content of alloying elements is high, especially the thick gauge weathering steel, so the developed process is simple, the performance is stable,...

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Problems solved by technology

In order to ensure that the mechanical properties meet the requirements, some patent inventions add a certain amount of Mo element, which greatly increases the alloy cost and reduces economic benefits; some patent inventions add a very high content of Cr element, and the Cr content control range is 2.5 to 10.0 %, a very high content of Cr not only greatly increases the cost and difficulty of smelting, but also has an adverse effect on the formability of the steel; some inventions described in patents use a lower coiling temperature to obtain a certain amount of bainite structure Improving mechanical properties, but lowering the coiling temperature is not conducive to the shape control of high-strength weathering steel. In addition, although the thickness specification of some inventions described in patents reaches 14.0mm, the strength level is low, and the yield strength is only 485MPa-525MPa, which is far lower than this invention

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