Thick gauge q450nqr1 steel plate and its rough rolling method

Abstract

The invention relates to weathering steel and a rolling method thereof, in particular to a thick-gauge Q450NQR1 steel plate and a rough rolling method thereof, and belongs to the technical field of steel and iron. The rough rolling method of the thick-gauge Q450NQR1 steel plate is characterized in that the steel plate is prepared from the following chemical ingredients in percentage by weight: 0.05 to 0.08 percent of C, 0.25 to 0.40 percent of Si, 0.8 to 1.45 percent of Mn, at most 0.018 percent of P, at most 0.008 percent of S, 0.32 to 0.38 percent of Cr, 0.12 to 0.20 percent of Ni, 0.20 to 0.25 percent of Cu, 0.05 to 0.06 percent of V, 0.03 to 0.045 percent of Nb and the balance of Fe and unavoidable impurities, wherein the rough rolling method uses odd-even pass whole-course whole-number scale removal; all scale removal water in odd-even passes is in the boiling state; the rolling is performed at a low speed. The difficult problem of original crystalline grain nonuniformity in the cooling process is solved; the cost is low.

Description

technical field [0001] The invention relates to weather-resistant steel and a rolling method thereof, in particular to a thick gauge Q450NQR1 steel plate and a rough rolling method thereof, and belongs to the technical field of iron and steel. Background technique [0002] The microstructure is an important factor in determining hot-rolled steel products. The uneven structure of the surface and the core often leads to poor mechanical properties of the product and large fluctuations. Especially in the low-temperature impact test, the uneven microstructure size often causes the difference in the ductile-brittle transition temperature, resulting in poor impact toughness or large fluctuations in impact toughness of the material. [0003] In the hot rolling process, due to the limitation of the law of deformation itself, under a certain amount of deformation, the strain rate of the surface layer is always greater than that of the core, resulting in the difference in the grain siz...

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