Method for preparing non-oriented silicon steel columnar crystal thin strip blank by twin-roll thin strip continuous casting

Abstract

The invention discloses a method for preparing a non-oriented silicon steel columnar crystal thin strip blank by twin-roll thin strip continuous casting, comprising the following steps of: smelting molten steel by utilizing an intermediate frequency vacuum induction furnace, wherein the molten steel contains the following chemical components in percentage by mass: 0.002-0.02 percent of C, 0.5-6.5 percent of Si, 0.01-1.0 percent of Mn, 0.01-1.0 percent of Al, 0.001-0.006 percent of S, 0.001-0.02 percent of P, 0.002-0.006 percent of N, 0.002-0.005 percent of O and the balance of Fe; enabling the molten steel to flow into a cavity formed by two reversely rotatable crystallizing rolls and a side dam through a tundish to form a molten pool; controlling the superheat degree of the molten steel on the upper surface of the molten pool to be 45-85 DEG C, the length of a contact arc of the molten steel in the molten pool and the surfaces of the crystallizing rolls to be 110-240mm and the contact time of the molten steel in the molten pool and the surfaces of the crystallizing rolls to be 0.4-0.7s, solidifying the molten steel through the crystallizing rolls and leading out to form the non-oriented silicon steel columnar crystal thin strip blank. With the method provided by the invention, the temperature gradient of the molten steel at the leading edge of a solid phase can be increased to create an advantage for forming a columnar crystal and inhibit the formation of an isometric crystal, and the non-oriented silicon steel thin strip blank with a developed columnar crystal tissue can be obtained, wherein the volume content of the columnar crystal is larger than 90 percent.

Description

technical field [0001] The invention belongs to the technical field of metallurgical continuous casting, and relates to the preparation technology of non-oriented silicon steel, in particular to a method for preparing non-oriented silicon steel columnar crystal thin strip blank by twin-roll strip continuous casting. Background technique [0002] Non-oriented silicon steel is mainly used as the iron core material of various motors. In order to reduce the energy loss during motor operation, the magnetic properties of non-oriented silicon steel must be further improved. The easy magnetization direction of the iron single crystal is the <001> direction, so the final crystal texture state of the non-oriented silicon steel sheet has a great influence on the magnetic properties. In small and medium-sized motors, non-oriented silicon steel sheets are punched into ring cores for use. Therefore, the non-oriented silicon steel sheet should have lower hoop iron loss and higher h...

AI Technical Summary

Problems solved by technology

However, due to the limitations of the directional solidification technology itself, it cannot produce thin slabs with large area, thin specifications, and columnar grain structure, so it cannot be effectively applied to the production of non-oriented silicon steel

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