Economical thin-specification Q355B steel plate and preparation method thereof

Abstract

The invention discloses an economical thin-specification Q355B steel plate and a preparation method thereof. The economical thin-specification Q355B steel plate comprises the following components of,in percentage by weight, 0.16%-0.19% of C, less than or equal to 0.24% of Si, less than or equal to 0.95% of Mn, 0.020%-0.045% of Al, 0.008%-0.015% of Nb, less than or equal to 0.10% of Cr, less thanor equal to 0.025% of P, less than or equal to 0.008% of S, less than or equal to 0.080% of N and the balance iron and inevitable impurities. The process route comprises the steps of molten iron KR pre-desulfurization, converter smelting, LF refining, soft stirring, slab continuous casting, slab reheating, rough rolling, finish rolling, steel plate rapid cooling, steel plate hot straightening, cooling on a cooling bed, shearing and warehousing.

Description

technical field [0001] The invention belongs to the technical field of structural steel metallurgy, and in particular relates to an economical thin Q355B steel plate and a preparation method thereof. Background technique [0002] Q355B is currently widely used in structures and mechanical parts that carry dynamic loads such as mining machinery and bridges. With the continuous progress of infrastructure construction in my country and other countries in the world, the demand for Q355B is increasing day by day, and it has become one of the steel grades generally mass-produced by major domestic iron and steel enterprises. [0003] The demand for Q355B continues to increase. In the past, steel plates of similar specifications often used a C-Mn-based composition system. Higher Mn content increased production costs. In addition, higher Mn content easily produced inclusions such as MnS, which affected performance. [0004] At present, the domestic production of steel plates with si...

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Problems solved by technology

[0005] Technical problem to be solved: This application mainly proposes an economical thin-gauge Q355B steel plate and its preparation method, which solves the technical problems in the prior art that the rolling process needs to be temperature-controlled rolling, and the rolling rhythm is relatively slow.

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