Device for refining grain structure and application method

Abstract

The invention discloses a device for refining grain structure and an application method, and belongs to the technical field of metallurgy. The device comprises a vibration device inserted in a steel ingot mold; the vibration device includes a vibration rod making direct contact with molten steel; the vibration rod is provided with a vibration generation source for driving the vibration rod to move; an introduction pipe for circulating a cooling medium is arranged in the center of the vibration rod; and discharge pipes for circulating the cooking medium are arranged on two sides of the upper end of the vibration rod. A steel ingot is vibrated in the solidification process to urge fusing and breakage of dendrites; and the number of free cold crystals is increased to inhibit growth of columnar crystals, so that the isometric crystal rate is increased, the solidification structure is refined, and the purpose of relieving segregation is achieved.

Description

technical field [0001] The invention relates to a device and a use method for refining the grain structure, in particular to a device and a use method suitable for refining the grain structure of a forged steel backup roll made of Cr5 and belongs to the technical field of metallurgy. Background technique [0002] In recent years, with the development of the steel rolling industry, in order to roll high-precision products, newly-built continuous rolling or single-stand rolling mills are mainly six-high rolling mills. In order to achieve rolling high-precision rolling and improve the production efficiency of the rolling mill, the rolling mill is gradually developing towards high speed and modernization. Among them, the large forged steel backup roll is the core functional part of the current rolling equipment, and mainly bears the rolling of the work roll or the intermediate roll. Load, with the continuous development and improvement of the rolling mill, the rolling pressure o...

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Problems solved by technology

[0004] However, when pouring steel ingots for forged steel backup rolls, internal defects such as segregation, shrinkage cavities, and shrinkage porosity are prone to occur. The formation of these defects is closely related to the pouring and solidification process; during the solidification process of steel ingots for forged steel backup rolls, the solidification process The momentum decays very quickly, and its interior is mainly in a state of natural convection. There are not only common "V"-shaped segregation defects in the large-section ingot, but sometimes there are inverted "V"-shaped defects between the center and the edge. segregation, which will further aggravate the severity of center porosity and shrinkage cavity defects. This kind of macro segregation seriously affects the structure and performance of steel ingots, and is difficult to eliminate through subsequent processes such as forging and heat treatment. Therefore, in order to obtain high hardness and high wear resistance backup roll, it is necessary to eliminate these defects

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