A kind of method for producing extra-thick plate continuous casting billet

Abstract

The invention relates to the field of metal continuous casting manufacturing, in particular to a method for producing an ultra-thick plate continuous casting blank by adopting fast cooling and unsymmetrical great pressing-down. According to the method, a continuous casting blank sequentially passes through a vertical section (2), an arc-shaped section (3), a straightening section (4) and a horizontal section (5) under a crystallizer (1), through the implementation of fast cooling and unsymmetrical great pressing-down in a secondary cooling region of a casting machine, the ferritiszation process of the casting blank surface layer is realized before the bending or straightening through the fast cooling process, in addition, the balanced separation of second-phase particles in crystals and at crystal boundaries is ensured, the surface layer tissues of the casting blank are improved, meanwhile, the deformation of a blank core part can be increased through the unsymmetrical great pressing-down process, the occurrence of surface cracks of medium and ultra-thick casting blanks in the bending and straightening process is prevented, and meanwhile, the center segregation and the center looseness of the ultra-thick casting blank is avoided. The method provided by the invention has the advantages that the surface quality and the center quality of the ultra-thick plate continuous casting plate can be better improved, so that the ultra-thick plate continuous casting blank can realize the rolling production of ultra-thick steel plates with the thickness being greater than 120mm at a low compression ratio.

Description

technical field [0001] The invention relates to the field of metal continuous casting, in particular to a method for producing extra-thick plate continuous casting slabs by adopting rapid cooling and asymmetric large reduction. Background technique [0002] Extra-thick plates are widely used in offshore platforms, shipbuilding, nuclear power, boilers, pressure vessels, high-pressure pipelines, water conservancy, bridges, mechanical molds, buildings and important structures, etc., and extra-thick plates are generally made of die-cast billets Rolling after billeting or composite billet rolling ensures the performance of the core of the plate through a reasonable compression ratio. [0003] At present, the domestic production of extra-thick plates (steel plates with a thickness of ≥100mm) is mainly produced by die-casting steel ingots or electroslag remelting ingots, such as Wugang, Baosteel and Yingkou Heavy Plate Plants, etc., and by composite billet casting. Special thick p...

AI Technical Summary

Problems solved by technology

At present, the existing continuous casting machines in my country can stably produce continuous casting slabs with a maximum thickness of 420mm. Although the rolling compression ratio can be guaranteed to be greater than 3, it is difficult to achieve single pass due to the limitation of rolling mill equipment capacity (rolling force, motor torque, etc.) The second largest reduction and deformation rate cannot completely eliminate the influence of segregation and porosity in the center of the slab on the core quality of steel plates with a thickness of more than 100 mm

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