Grain-oriented electrical steel sheet and method for manufacturing same

Abstract

Provided is a grain-oriented electrical steel sheet having a linear groove forming an angle of 45° or less with the direction perpendicular to the direction of rolling, wherein a grain-oriented electrical steel sheet having low iron loss characteristics, on which a magnetic domain subdivision treatment by chemical means is used, is provided by setting the incidence of microparticles having a length of 1 mm or less in the rolling direction in a bottom part of the groove to 10% or less (also including cases in which microparticles are not present), providing a forsterite coating in which the Mg weight per side of the steel sheet is at least 0.6 g / m2 in the groove, and setting the angle (beta angle) between a rolling surface and the <100> axis of a secondary recrystallized grain oriented in the rolling direction of the steel sheet to an average value of 3° or less.

Description

technical field

[0001] The present invention relates to a grain-oriented electrical steel sheet used as an iron core material for transformers and the like, and a method for manufacturing the same. Background technique

[0002] Grain-oriented electrical steel sheets are mainly used as iron cores of transformers, which require excellent magnetization characteristics, especially low iron loss.

[0003] Therefore, it is important to highly concentrate secondary recrystallized grains in the steel sheet in the (110)

[001] orientation (so-called Goss orientation) and to reduce impurities in the product steel sheet.

[0004] However, there are limits in the control of crystal orientation and reduction of impurities due to trade-off with manufacturing cost and the like. Therefore, a method of reducing iron loss by introducing linear strain into a grain-oriented electrical steel sheet to narrow the magnetic domain width is known.

[0005] As a method of improving iron loss by narrow...

Examples

Embodiment 1

[0103] Containing C: 0.06%, Si: 3.3%, Mn: 0.08%, S: 0.023%, Al: 0.03%, N: 0.007%, Cu: 0.2% and Sb: 0.02%, and the balance is Fe and unavoidable The slab with impurities was heated at 1430°C for 30 minutes, then hot-rolled to form a hot-rolled sheet with a thickness of 2.2mm, and then annealed at 1000°C for 1 minute, and then cold-rolled until the thickness of the sheet: 1.5mm. Rolling and intermediate annealing at 1100° C. for 2 minutes, and then cold rolling to a final plate thickness of 0.23 mm. Next, linear grooves are formed by electrolytic etching or pressing with protruding rolls. Thereafter, decarburization annealing was performed at 840° C. for 2 minutes, and 10% by mass of TiO was contained in MgO: 90% by mass having a viscosity (30 minutes after mixing with water) and physical properties shown in Table 1. 2 The mixed powder was mixed with water (solid content ratio: 15% by mass), and stirred for 30 minutes to form a slurry, and an annealing separator with the viscos...

Embodiment 2

[0112] After heating the billet containing the components shown in Table 2-1 and Table 2-2 at 1430°C for 30 minutes, it was hot-rolled to form a hot-rolled sheet with a thickness of 2.2mm, and annealed at 1000°C for 1 minute. Then implement cold rolling up to plate thickness: 1.5mm, and further implement intermediate annealing at 1100°C for 2 minutes. According to the cold rolling conditions shown in Table 3 (the maximum temperature on the input and output sides is 170°C or less. The number of passes is two. The maximum temperature of the input and output side is 200°C or more, and the number of passes is three times) to make a final plate thickness of 0.23 mm, and form linear grooves by electrolytic etching.

[0113] Next, after performing decarburization annealing at 840° C. for 2 minutes, MgO (viscosity (after 30 minutes after mixing with water) is 40 cP) as the main component (93% by mass) and 6% by mass of TiO 2 , 1% by mass SrSO 4 The annealing separating agent and wate...

technical field

[0001] The present invention relates to a grain-oriented electrical steel sheet used as an iron core material for transformers and the like, and a method for manufacturing the same. Background technique

[0002] Grain-oriented electrical steel sheets are mainly used as iron cores of transformers, which require excellent magnetization characteristics, especially low iron loss.

[0003] Therefore, it is important to highly concentrate secondary recrystallized grains in the steel sheet in the (110)

[001] orientation (so-called Goss orientation) and to reduce impurities in the product steel sheet.

[0004] However, there are limits in the control of crystal orientation and reduction of impurities due to trade-off with manufacturing cost and the like. Therefore, a method of reducing iron loss by introducing linear strain into a grain-oriented electrical steel sheet to narrow the magnetic domain width is known.

[0005] As a method of improving iron loss by narrow...

Examples

Embodiment 1

[0103] Containing C: 0.06%, Si: 3.3%, Mn: 0.08%, S: 0.023%, Al: 0.03%, N: 0.007%, Cu: 0.2% and Sb: 0.02%, and the balance is Fe and unavoidable The slab with impurities was heated at 1430°C for 30 minutes, then hot-rolled to form a hot-rolled sheet with a thickness of 2.2mm, and then annealed at 1000°C for 1 minute, and then cold-rolled until the thickness of the sheet: 1.5mm. Rolling and intermediate annealing at 1100° C. for 2 minutes, and then cold rolling to a final plate thickness of 0.23 mm. Next, linear grooves are formed by electrolytic etching or pressing with protruding rolls. Thereafter, decarburization annealing was performed at 840° C. for 2 minutes, and 10% by mass of TiO was contained in MgO: 90% by mass having a viscosity (30 minutes after mixing with water) and physical properties shown in Table 1. 2 The mixed powder was mixed with water (solid content ratio: 15% by mass), and stirred for 30 minutes to form a slurry, and an annealing separator with the viscos...

Embodiment 2

[0112] After heating the billet containing the components shown in Table 2-1 and Table 2-2 at 1430°C for 30 minutes, it was hot-rolled to form a hot-rolled sheet with a thickness of 2.2mm, and annealed at 1000°C for 1 minute. Then implement cold rolling up to plate thickness: 1.5mm, and further implement intermediate annealing at 1100°C for 2 minutes. According to the cold rolling conditions shown in Table 3 (the maximum temperature on the input and output sides is 170°C or less. The number of passes is two. The maximum temperature of the input and output side is 200°C or more, and the number of passes is three times) to make a final plate thickness of 0.23 mm, and form linear grooves by electrolytic etching.

[0113] Next, after performing decarburization annealing at 840° C. for 2 minutes, MgO (viscosity (after 30 minutes after mixing with water) is 40 cP) as the main component (93% by mass) and 6% by mass of TiO 2 , 1% by mass SrSO 4 The annealing separating agent and wate...

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