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...

Examples

Embodiment 1

[0034] Prepare raw materials according to the following chemical composition in mass percentage: C: 0.0029%, Si: 1.48%, Al: 0.39%, Mn: 0.79%, P: 0.021%, N: 0.0035%, S: 0.0039%, the rest is iron and To avoid impurities, carry out smelting and vacuum refining.

[0035] Afterwards, thin slab continuous casting is carried out, and the liquid core reduction process is adopted to reduce the thickness of the slab from 90mm at the exit of the crystallizer to 60mm. %, the average grain size of the equiaxed grains is about 1.62mm, and the distance between the primary dendrite arms of the columnar grains in the slab is about 380μm; after soaking at 1130°C, it is hot-rolled, and the first-pass rolling reduction rate is 49% ; After pickling, the hot-rolled sheet is cold-rolled to a thickness of 0.5 mm, and then annealed and coated in a continuous annealing and coating unit.

[0036] Finished iron loss P 15 / 50 3.27W / kg, magnetic induction B 50 It is 1.70T, and there are no corrugated def...

Embodiment 2

[0038] Raw materials are prepared according to the chemical composition of the following mass percentages: C: 0.0036%, Si: 1.25%, Al: 0.90%, Mn: 0.31%, P: 0.07%, N: 0.0038%, S: 0.0038%, and the rest is iron and To avoid impurities, carry out smelting and vacuum refining.

[0039] Afterwards, thin slab continuous casting is carried out, and the liquid core reduction process is adopted to reduce the thickness of the slab from 90mm at the exit of the crystallizer to 60mm. %, the average grain size of equiaxed grains is about 1.50mm, and the primary dendrite arm spacing of columnar grains in the slab is about 340μm; after soaking at 1120°C, hot rolling is performed, and the reduction rate of the first rolling pass is 48% ; After pickling, the hot-rolled sheet is cold-rolled to a thickness of 0.5 mm, and then annealed and coated in a continuous annealing and coating unit.

[0040] Finished iron loss P 15 / 50 3.44W / kg, magnetic induction B 50 It is 1.72T, and there are no corrugat...

Embodiment 3

[0042]Raw materials are prepared according to the chemical composition of the following mass percentages: C: 0.0051%, Si: 1.36%, Al: 0.69%, Mn: 0.50%, P: 0.03%, N: 0.0036%, S: 0.0040%, and the rest is iron and To avoid impurities, carry out smelting and vacuum refining.

[0043] Afterwards, thin slab continuous casting is carried out, and the liquid core reduction process is adopted to reduce the thickness of the slab from 90mm at the exit of the crystallizer to 55mm. %, the average grain size of equiaxed grains is about 1.47mm, and the primary dendrite arm spacing of columnar grains in the slab is about 355μm; after soaking at 1140°C, hot rolling is carried out, and the rolling reduction rate of the first pass is 45% ; After pickling, the hot-rolled sheet is cold-rolled to a thickness of 0.5 mm, and then annealed and coated in a continuous annealing and coating unit.

[0044] Finished iron loss P 15 / 50 3.39W / kg, magnetic induction B 50 It is 1.71T, and there are no corruga...

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...

Examples

Embodiment 1

[0034] Prepare raw materials according to the following chemical composition in mass percentage: C: 0.0029%, Si: 1.48%, Al: 0.39%, Mn: 0.79%, P: 0.021%, N: 0.0035%, S: 0.0039%, the rest is iron and To avoid impurities, carry out smelting and vacuum refining.

[0035] Afterwards, thin slab continuous casting is carried out, and the liquid core reduction process is adopted to reduce the thickness of the slab from 90mm at the exit of the crystallizer to 60mm. %, the average grain size of the equiaxed grains is about 1.62mm, and the distance between the primary dendrite arms of the columnar grains in the slab is about 380μm; after soaking at 1130°C, it is hot-rolled, and the first-pass rolling reduction rate is 49% ; After pickling, the hot-rolled sheet is cold-rolled to a thickness of 0.5 mm, and then annealed and coated in a continuous annealing and coating unit.

[0036] Finished iron loss P 15 / 50 3.27W / kg, magnetic induction B 50 It is 1.70T, and there are no corrugated def...

Embodiment 2

[0038] Raw materials are prepared according to the chemical composition of the following mass percentages: C: 0.0036%, Si: 1.25%, Al: 0.90%, Mn: 0.31%, P: 0.07%, N: 0.0038%, S: 0.0038%, and the rest is iron and To avoid impurities, carry out smelting and vacuum refining.

[0039] Afterwards, thin slab continuous casting is carried out, and the liquid core reduction process is adopted to reduce the thickness of the slab from 90mm at the exit of the crystallizer to 60mm. %, the average grain size of equiaxed grains is about 1.50mm, and the primary dendrite arm spacing of columnar grains in the slab is about 340μm; after soaking at 1120°C, hot rolling is performed, and the reduction rate of the first rolling pass is 48% ; After pickling, the hot-rolled sheet is cold-rolled to a thickness of 0.5 mm, and then annealed and coated in a continuous annealing and coating unit.

[0040] Finished iron loss P 15 / 50 3.44W / kg, magnetic induction B 50 It is 1.72T, and there are no corrugat...

Embodiment 3

[0042]Raw materials are prepared according to the chemical composition of the following mass percentages: C: 0.0051%, Si: 1.36%, Al: 0.69%, Mn: 0.50%, P: 0.03%, N: 0.0036%, S: 0.0040%, and the rest is iron and To avoid impurities, carry out smelting and vacuum refining.

[0043] Afterwards, thin slab continuous casting is carried out, and the liquid core reduction process is adopted to reduce the thickness of the slab from 90mm at the exit of the crystallizer to 55mm. %, the average grain size of equiaxed grains is about 1.47mm, and the primary dendrite arm spacing of columnar grains in the slab is about 355μm; after soaking at 1140°C, hot rolling is carried out, and the rolling reduction rate of the first pass is 45% ; After pickling, the hot-rolled sheet is cold-rolled to a thickness of 0.5 mm, and then annealed and coated in a continuous annealing and coating unit.

[0044] Finished iron loss P 15 / 50 3.39W / kg, magnetic induction B 50 It is 1.71T, and there are no corruga...

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