Production method of ultra-thick steel plate

Abstract

The invention discloses a production method of an ultra-thick steel plate, mainly comprising pretreatment of molten iron, smelting in a converter, external refining, and continuous casting, rolling and cooling of a slab. The production method is characterized in that LF (ladle furnace) refining treatment and VD (vacuum degassing) are adopted; ferrovanadium is added before tapping, the added amount is 1-1.5kg/t steel, an electromagnetic stirring technology is applied in the continuous casting process, the heating temperature of the slab before rolling is controlled to be 1150-1220 DEG C so as to guarantee fine austenitic grain, high-pressure water is used for removing phosphorus fully before rolling and in the rolling process, the starting rolling temperature of a steel billet is controlled to be 1100 plus or minus 50 DEG C, and the thickness of a middle billet is controlled to be 1.2-1.49 times that of a finished product; the final rolling temperature is 830 plus or minus 20 DEG C when the thickness is 71-100mm, then air cooling is carried out till room temperature; and the final rolling temperature is 860 plus or minus 20 DEG C when the thickness is 101-150mm, the steel plate enters laminar flow for cooling, and the red-returning temperature is 720 plus or minus 20 DEG C after cooling. The production method has the advantages that the production efficiency is high, large-batch production is favored, the mechanical properties are good and the like; and the yield strength Rel is larger than or equal to 330MPa, the impact power AKv at the temperature of -20 DEG C is larger than or equal to 150J, and the production method is applicable to most of mechanical members and use temperature.

Description

technical field [0001] The invention belongs to the technical field of metal materials, and in particular relates to a production method of an extra-thick steel plate. Background technique [0002] Today, with the rapid development of science and technology and modern industry, the market demand for extra-thick steel plates for machinery and construction is increasing, and the performance requirements for steel plates are getting higher and higher. More than 100mm. Extra-thick plates can be widely used in construction machinery, bridges, containers, vehicles, ships, electrical equipment and other structural parts. However, it is difficult to produce such large thickness specifications to ensure qualified and uniform performance. [0003] At present, most of the extra-thick plates are produced by die casting, which has low yield, low production efficiency and high production cost. For example, Wuyang Iron and Steel Co., Ltd. applied for a patent named "A Large Thickness Que...

AI Technical Summary

Problems solved by technology

[0008] The production process is complicated, the production efficiency is low, and delamination defect

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