Low-grade non-oriented silicon steel produced in continuous casting and rolling processes of sheet billet and preparation method thereof

Abstract

The invention belongs to the field of metallurgy, and relates to low-grade non-oriented silicon steel produced in continuous casting and rolling processes of a sheet billet and a preparation method thereof. The low-grade non-oriented silicon steel comprises the ingredients by weight percent: 0.001-0.008% of C, 1.10-1.70% of Si, 0.20-1.0% of Al, 0.20-1.0% of Mn, 0.02-0.10% of P, no more than 0.005% of N, no more than 0.005% of S, the balance of iron and inevitable impurities; and existence of 10-30% of austenite phase [gamma 1100 DEG C=26.5+655(%C)-14.2(%Si)+4.2(%Mn)-2.68(%Al)+665(%N)-18.4(%P)] is ensured by ingredient ratio when steel is at 1100 DEG C. The 50W470-grade non-oriented silicon steel product produced by the preparation method disclosed by the invention is good in magnetic property, and does not generate corrugated shape defects; the preparation method disclosed by the invention does not need to transform equipment at a large scale; the normalizing procedure of a hot rolled plate is emitted; secondary cold rolling is not needed; the production procedure is reduced; and the production cost is also reduced.

Description

technical field [0001] The invention belongs to the field of metallurgy, and relates to a low-grade non-oriented silicon steel produced by a thin slab continuous casting and rolling process and a preparation method thereof. Background technique [0002] The thin slab continuous casting and rolling production process is short, the slab is thin, and the heat loss in the process is small, which can save a lot of energy and reduce costs. Moreover, due to the short rolling line length and small temperature drop, high-temperature final rolling and high-temperature coiling can be realized, and non-oriented silicon steel with excellent magnetic properties can be produced. [0003] The non-oriented silicon steel slab produced by thin slab continuous casting and rolling is thin, with fast casting speed and well-developed columnar crystals. In the production process of 50W470 grade non-oriented silicon steel, the content of Si and Al in the steel is generally Si+Al>1.5%. When the c...

AI Technical Summary

Problems solved by technology

However, this method requires the heating temperature of the continuous casting slab to be raised to above 1250°C, which may easily cause the continuous casting slab to collapse, affect the conveying of the roller table and generate internal cracks inside the continuous casting slab

[0009] 5. Increase the recrystallization rate of the steel plate by normalizing the hot-rolled plate and secondary cold rolling to eliminate corrugated defects, but this method increases the production cost

However, the hot-rolled coils in the hot-rolling process need to be coiled at a high temperature above 700°C, resulting in dense oxide scales on the surface of the hot-rolled coils, which increases the burden of pickling; and the production process control requires high precision and is difficult. Lower rate rolling causes a larger load on the rolling mill, and it is difficult to control the shape of the plate

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