CN100436042C - Thin slab process high magnetic induction oriented electrical steel sheet and its manufacturing method - Google Patents

Abstract

The present invention relates to a sheet billet technology high magnetic induction oriented electrical steel plate and a manufacturing method thereof. The present invention has the technical scheme that the thickness of the sheet billet technology is from 50 to 120mm, and the chemical components of the sheet billet are 0.030 to 0.050 wt% of C, 2.9 to 3.3 wt% of Si, 0.001 to 0.04 wt% of Als, 0.01 to 0.12 wt% of Nb, 0.004 to 0.012 wt% of N, at most 0.015 wt% of P, the rest comprises Fe and unavoidable foreign matter, and AlN and Nb (C, N) are used as inhibitors. The sheet billet is heated to the temperature of 1150 to 1300 DEG C, and the temperature is preserved for 2 to 5 hours; then the hot rolling, the quick cooling and the coiling of the sheet billet are carried out; then the sheet billet is rolled according to a primary or a secondary cold rolling method, and the plate thickness is not larger than 0.30mm; the decarburizing annealing is carried out, a magnesium oxide isolation layer is coated, the sheet billet is coiled, and finally, the high temperature annealing is carried out. The present invention has the advantages of simple manufacturing processes, and low heating temperature and ultimate high temperature annealing temperature, and hot rolling plate normalization can be omitted; the manufactured sheet billet technology oriented electrical steel plate has the characteristics of high magnetic induction and low iron loss.

Description

A thin slab process high magnetic induction oriented electrical steel sheet and its manufacturing method

1. Technical field:

The invention belongs to the technical field of oriented electrical steel plates. In particular, it relates to a thin slab process high magnetic induction oriented electrical steel sheet and a manufacturing method thereof.

2. Background technology

For thin slab continuous casting machines, the cooling intensity is high and the cooling speed is fast. The oxides, sulfides and nitrides precipitated during rapid solidification are fine. The experimental research of Hou Teng Yugui et al. shows (Hou Teng Yugui et al.: Precipitation characteristics of oxides in steel during rapid solidification, Iron and Steel, 1997, vol.83, No.12, p.61. Zhou Deguang, Fu Jie, Wang Zhongbing, Li Jing, Xu Zhongbo, Liu Delu, Kang Yonglin, Chen Guijiang, Li Liejun: As-Cast Microstructure Characteristics of CSP Thin Slab, 2002 International Symposium on Thin Slab Casting and Rolling, Guangzhou, December 2002. Liu Delu, Chen Nanjing , Huo Xiangdong, Wang Yuanli, Fu Jie, Kang Yonglin: Research on Nanoscale Precipitated Particles in Low Carbon Steel by EAF-CSP Process, 2002 International Symposium on Thin Slab Casting and Rolling, Guangzhou, December 2002), when rapid solidification , oxides, sulfides and nitrides are small in size. For grain-oriented electrical steel, it is hoped that the precipitates such as MnS and AlN are fine and uniform, and the thin slab continuous casting process is beneficial to the production of grain-oriented electrical steel.

Because the thin slab as-cast structure has fine and uniform grain size and fine and uniform precipitates, the difference between the surface layer and the central layer near the cast slab is small, and the segregation is also small. Therefore, the thin slab process is conducive to the production of grain-oriented electrical steel (Amco’s Conroll continuous casting-continuous rolling plant operation effect, "International Steel Age" Chinese version, September 1998, p.8).

In addition, for the thin slab continuous casting and rolling process, since all the continuous casting slabs are directly rolled, there is no cooling and reheating process of the slab, which can make full use of the heat of the slab and save a lot of energy. Compared with the traditional thick slab process , can save 60% of energy (Xie Taifeng, Liang Yonglin: Comprehensive Economic Comparison and Selection of Different Process Continuous Casting and Rolling Processes, Steel Rolling, 18(2001), No.2, pp.25-27). For oriented electrical steel, it can not only save a lot of energy, but also avoid the increase of scrap rate caused by internal cracks or even broken slabs that may occur during the cooling process and reheating process of the continuous casting slab. For grain-oriented electrical steel, due to the good temperature uniformity of the slab, the edge cracks are reduced (the operation effect of Amco's Conroll continuous casting-rolling plant, "International Steel Age" Chinese version, September 1998, p.8) . It can be seen that compared with the traditional thick slab process, the thin slab process has an improved yield.

At present, the industrial production method using slab low-temperature heating process uses AlN as an inhibitor, and nitriding treatment is carried out before the secondary recrystallization begins (Fortunati et al: Us patent, Patent No. Us 6296719B1, October 2, 2001; original Sejiro et al.: Production method of grain-oriented electrical steel with microalloying to improve magnetic induction after annealing, Wuhan Iron and Steel Technology, 35 (1997), No. 6, pp.48-50), or AlN as the main inhibitor, Cu ₂ S and MnS are auxiliary inhibitors (Chol Gyu Seung et al: Low-temperature slab heating process is used in the production of grain-oriented electrical steel sheets in Pohang, Wuhan Iron and Steel Technology, 35 (1997), No. 8, pp.48-50). The method is to nitriding the steel to combine with the original elements in the steel to form AlN precipitates with inhibitor function. The inhibitor used in the slab low-temperature heating process is mainly AlN, because the solid solution temperature of AlN is lower than that of MnS, which is more suitable for low-temperature heating. When the heating temperature of the slab is lowered to 1150-1200°C according to the AlN scheme, in order to obtain a complete secondary recrystallization structure, high magnetic properties and a good glass film, corresponding composition adjustments and process improvements must be made. The Hi-B new process researched by Nippon Steel (Komatsu Hajime et al.: The manufacturer of magnetic flux density の high い directional silicon steel plate, Int.c: C21D8/12, Japanese Patent Publication, Special Publication No. 62240315.1987.02.21) is characterized by : With AlN as the inhibitor, the heating temperature of the slab is reduced to 1150-1250°C, and after decarburization annealing, nitriding treatment is carried out in the H ₂ +N ₂ atmosphere containing NH ₃ , and the 0.18-0.50mm can be produced by one-time cold rolling method. Thick products, and easier to make new products without glass film. Sumitomo Metal proposes the low-carbon 1.5%Mn2.2%si oriented electrical steel process with AlN as the inhibitor to reduce the slab heating temperature (edited by He Zhongzhi, Electrical Steel, Beijing: Metallurgical Industry Press, 1996,796,802- 803, 811-813, 839-840; He Zhongzhi: Recent Development of Electrical Steel, Metal Functional Materials, 1997, 4(6): pp.243～245). Pohang Iron and Steel Company of South Korea proposed to use AlN as the main inhibitor, Cu ₂ S and MnS as auxiliary inhibitors, and heat the slab at 1250-1320 °C to produce general-oriented electrical steel and high-magnetic-inductive oriented electrical steel (Chol Gyu Seung et al. al: Low-temperature slab heating process is used in the production of Pohang grain-oriented electrical steel sheets, Wuhan Iron and Steel Technology, 35 (1997), No. 8, pp.48-50). Its slab composition is: C 0.035%~0.05%, Si2.9%~3.3%, P<0.015%, Als 0.011%~0.017%, N 0.008%~0.012%, S<0.007%, Ni and/or Cr 0.06%～0.08%, Mn 0.32%, Cu<0.6%, and Mn/s≥20.0, Cu/Mn>1.5.

The high-temperature heating process of casting slabs used in industrial production of oriented electrical steel can obtain stable high magnetic properties, but the disadvantage is that there are many oxide slags, the burning loss can reach 5%, and the yield is low; the bottom of the furnace must be cleaned frequently, and the output is reduced; fuel High cost; short furnace life; high manufacturing cost; many surface defects.

Manufacture of grain-oriented electrical steel has been trying to reduce the heating temperature of the billet. The main method used by Nippon Steel and Sumitomo Metals to reduce the heating temperature of the slab is to use AlN as the main inhibitor and carry out nitriding treatment, which has many process links, complicated technology and high difficulty. South Korea's Pohang Iron and Steel Company uses AlN as the main inhibitor, and Cu ₂ S and MnS as auxiliary inhibitors. The composition is complex, the heating temperature is high, and the final annealing temperature is high. The thin slab technology in the United States uses AlN as the main inhibitor, and MnS/MnSe, Cu ₂ S and Sn as auxiliary inhibitors. The composition is complex and requires high temperature normalization (Fortunati et al: US patent, Patent No. Us 6296719B1, October 2 , 2001).

3. Contents of the invention

The object of the present invention is to provide a thin slab with reasonable chemical composition, low manufacturing cost, omission of normalization (annealing) of hot-rolled sheet, low heating temperature and final high-temperature annealing temperature, high magnetic induction, low iron loss, and simple production process Process high magnetic induction oriented electrical steel sheet and its manufacturing method.

In order to achieve the above object, the technical solution adopted in the present invention is: the thickness of the thin slab process is 50-120mm, and the chemical composition of the slab is: C is 0.030-0.050wt%, Si is 2.9-3.3wt%, Als is 0.001 ~0.04wt%, Nb is 0.01~0.12wt%, N is 0.004~0.012wt%, P is <0.015wt%, the rest is Fe and unavoidable impurities, and the inhibitors are AlN and Nb(C, N); Heating the slab to 1150-1300°C and keeping it warm for 2-5 hours; then hot rolling, rapid cooling and coiling; then rolling to a plate thickness of ≤0.30mm by one or two cold rolling methods; then decarburization Annealed, coated with a magnesium oxide isolation layer, rolled into rolls, and finally high-temperature annealed.

Among them: the thin slab process is that the slab casting speed is 3-6m/min, the superheated degree of molten steel is 20-40°C, and the equiaxed grain rate of the slab is 30-80%. The inhibitor Nb(C,N) is one or more mixed precipitates of NbC, NbN and Nb(CN).

In the last 1-3 passes of the hot rolling process, the reduction rate is 10-30%, the final rolling temperature is 800-1050°C, and the relaxation time after rolling is 1-1000 seconds. condition for a certain period of time. Then carry out rapid cooling, and the cooling rate is 10-200° C./second to obtain a hot-rolled coil with fine and uniform precipitates and structures, and cancel the normalization annealing of the hot-rolled coil.

The first cold rolling method is a large cold rolling reduction, the total reduction rate is ≥ 80%, and the decarburization annealing is performed directly; the second cold rolling method is an intermediate annealing after the first cold rolling, and the intermediate annealing temperature is 800 ~ 1050 ° C , carried out in a nitrogen-hydrogen mixed atmosphere, entering the furnace through humidification, the dew point is 1-50 ° C, the time in the furnace is 5-3000 seconds, the reduction rate of the second cold rolling is 40-70%, the second cold rolling method The middle thickness is 0.50 ~ 0.90mm.

The decarburization annealing temperature is below 900°C, carried out in a nitrogen-hydrogen mixed atmosphere, entering the furnace through humidification, the dew point is 25-55°C, and the time in the furnace is less than 1-60 minutes; during high-temperature annealing, it is rapidly heated to 400°C to 10-100°C/hour heating rate to 600°C, then heating to 1100-1200°C at a rate of 15-50°C/hour, keeping warm for 15-30 hours, and then cooling; use protective atmosphere N during heating at 400-1200°C ₂ 25%+H ₂ 75%, and the protective gas 100% H ₂ is used in the heat preservation stage.

Due to the adoption of the above technical scheme, the present invention selects AlN and Nb(C,N) as inhibitors by rationally designing the composition of the grain-oriented electrical steel, and the slab is heated in the temperature range of 1200-1320°C, and then hot-rolled, cold-rolled and heat-treated. In particular, uniform and fine precipitates and structures can be obtained by controlling the reduction of each pass of hot rolling and the final rolling temperature, as well as the relaxation and cooling of the hot strip. The present invention can manufacture high magnetic induction oriented electrical steel sheets in thin slab technology with secondary recrystallization of (110)(001) high orientation degree, high magnetic induction and low iron loss without adding new equipment.

The chemical composition design of the steel grade of the invention is reasonable, the production process is simple, the normalization (annealing) of the hot-rolled sheet can be omitted, and the heating temperature and final high-temperature annealing temperature are low. Mainly manifested in:

1. Due to the high cooling intensity and fast cooling speed of the thin slab continuous casting machine, the obtained structure is relatively fine, and the carbides and nitrides precipitated during the rapid solidification process are uniform and fine. At the same time, since the thin slab continuous casting slab has no cooling-reheating process, compared with the traditional thick slab process, the solid solution temperature of the inhibitor can be appropriately lowered.

2. Since the present invention uses AlN and Nb(C,N) as inhibitors, their solid solution temperature is lower than that of MnS, so the heating temperature of the slab can be reduced to 1150-1300°C.

3. Due to the high cooling intensity and fast cooling speed of the thin slab continuous casting machine, the carbides and nitrides precipitated during the rapid solidification process are uniform and fine, and then by controlling the reduction of each pass of hot rolling, the final rolling temperature, The relaxation and rapid cooling of the hot-rolled strip can obtain uniform and fine precipitates and structures, so the normalization annealing (normalization) of the hot-rolled strip is omitted.

4. By adjusting the contents of Als, Nb, C, and N, and by controlling the reduction of each pass of hot rolling, the final rolling temperature, the relaxation of the hot strip and rapid cooling to obtain uniform and fine precipitates and structures, the grain size can be guaranteed. The strength of the grain growth inhibitor can significantly inhibit the primary grain growth, obtain stable magnetic properties, ensure that the magnetic properties are higher than that of ordinary grain-oriented electrical steel sheets, and obtain high magnetic induction grain-oriented electrical steel with B ₁₀ ≥ 1.89T, thereby improving grain-oriented electrical steel sheets manufacturing method.

5. Since AlN and Nb(C,N) are used as inhibitors, a lower final annealing temperature (1100-1200°C) can be used to obtain high magnetic induction oriented electrical steel.

4. Specific implementation

Below in conjunction with embodiment, the present invention will be further described.

Example 1 A kind of manufacturing method of thin slab process high magnetic induction oriented electrical steel sheet

A new type of oriented electrical steel, the thickness of the slab is 60mm, its chemical composition is: C is 0.035wt%, Si is 3.12wt%, Als is 0.02wt%, Nb is 0.04wt%, N is 0.0080wt%, P is 0.013 wt%, and the balance is Fe and unavoidable impurities.

The casting speed of the slab is 4.5m/min, the superheating degree of the molten steel is 20-30°C, and an electrical steel casting slab with an equiaxed crystal ratio of 55% is obtained. The heat preservation temperature of the electrical steel thin slab is 1190°C, and the heat preservation is 2 hours. Carry out hot rolling again, and the hot rolling is rolled to 2.2mm; The reduction rate of the last 3 passes of the hot rolling process is 15%, the final rolling temperature is 900° C., and the relaxation time after rolling is 40 seconds. Rapid cooling and coiling are then performed at a cooling rate of 40°C/sec. The hot-rolled coils with fine and uniform precipitates and structures are obtained, and the normalizing annealing of the hot-rolled coils is cancelled.

Then adopt the second cold rolling method, one cold rolling to 0.7mm, and then carry out intermediate annealing, the intermediate annealing temperature is 900 ° C, carried out in a nitrogen-hydrogen mixed atmosphere, enter the furnace through humidification, the dew point is 25 ° C, and the time in the furnace is For 600 seconds, the reduction rate of the second cold rolling is 57%, and the final thickness is 0.30mm.

Then decarburization annealing is carried out, the decarburization annealing temperature is 880°C, it is carried out in a nitrogen-hydrogen mixed atmosphere, it enters the furnace through humidification, the dew point is 25°C, and the time in the furnace is less than 0.8 hours.

Finally, it is coated with a magnesium oxide isolation layer, coiled, and annealed at high temperature. During high-temperature annealing, rapidly heat to 400°C, heat to 650°C at a heating rate of 10-100°C/hour, then heat to 1180°C at a rate of 20°C/hour, keep at 1180°C for 20 hours, and then cool. During the heating process at 400-1180°C, a protective atmosphere of N ₂ 25%+H ₂ 75% is used, and a protective gas of 100% H ₂ is used in the heat preservation stage.

The chemical composition design of the steel grade in Example 1 is reasonable, the production process is simple, the normalization (annealing) of the hot-rolled sheet can be omitted, and the heating temperature and final high-temperature annealing temperature are low. In Example 1, without adding new equipment, a thin slab process high magnetic induction orientation with (110) (001) high orientation degree secondary recrystallization, high magnetic induction, low iron loss and improved product quality can be manufactured Electrical steel plate. After determination, the chemical composition of the slab and the magnetic properties of the finished product are shown in Table 1:

Table 1 Slab composition and crystallization magnetic properties

Example 2 A kind of manufacturing method of thin slab process high magnetic induction oriented electrical steel sheet

A new type of oriented electrical steel sheet, the slab thickness is 60mm, its chemical composition is: C is 0.045wt%, Si is 3.18wt%, Als is 0.01wt%, Nb is 0.09wt%, N is 0.010wt%, P is 0.014 wt%, and the balance is Fe and unavoidable impurities.

The slab casting speed is 4.3m/min, the superheated degree of molten steel is 20-30°C, and an electrical steel slab with an equiaxed crystal ratio of 60% is obtained. The heat preservation temperature of the electrical steel thin slab is 1200°C, and the heat preservation is 2 hours. Then hot rolling, rapid cooling and coiling. Hot-rolled to 2.2mm, the reduction ratio of the last two passes of the hot-rolled process is 25%, the final rolling temperature is 950°C, and the relaxation time after rolling is 60 seconds. Rapid cooling is then performed at a cooling rate of 40° C./sec. To obtain precipitates and microstructure uniform and appropriate hot-rolled coils, this embodiment cancels the normalization annealing of hot-rolled coils.

Then use the second cold rolling method to carry out cold rolling, the first cold rolling to 0.7mm, and then carry out intermediate annealing, the intermediate annealing temperature is 1000 ° C, carried out in a nitrogen-hydrogen mixed atmosphere, enter the furnace through humidification, and the dew point is 45 ° C , the furnace time is 900 seconds, the reduction rate of the second cold rolling is 57%, and the final thickness is 0.30mm.

Then decarburization annealing is carried out. The decarburization annealing temperature is 890°C, and it is carried out in a nitrogen-hydrogen mixed atmosphere. It enters the furnace through humidification. The dew point is 35°C, and the time in the furnace is less than 0.9 hours.

Finally, it is coated with a magnesium oxide isolation layer, coiled, and annealed at high temperature. During high-temperature annealing, heat rapidly to 400°C, heat to 650°C at a heating rate of 10-100°C/hour, then heat to 1200°C at a rate of 20°C/hour, keep at 1200°C for 20 hours, and then cool. During the heating process at 400-1200°C, a protective atmosphere of N ₂ 25%+H ₂ 75% is used, and a protective gas of 100% H ₂ is used in the heat preservation stage.

The chemical composition design of the steel grade in Example 2 is reasonable, the production process is simple, the normalization (annealing) of the hot-rolled sheet can be omitted, and the heating temperature and final high-temperature annealing temperature are low. In Example 2, without adding new equipment, a thin slab process high magnetic induction orientation with (110) (001) high orientation secondary recrystallization, high magnetic induction, low iron loss and improved product quality can be manufactured Electrical steel plate. After determination, the chemical composition of the slab and the magnetic properties of the finished product are shown in Table 2:

Table 2 Slab Composition and Finished Magnetic Properties

Example 3 A manufacturing method of thin slab technology high magnetic induction oriented electrical steel sheet

A new type of oriented electrical steel sheet, the slab thickness is 60mm, its chemical composition is: C is 0.040wt%, Si is 3.15wt%, Als is 0.03wt%, Nb is 0.06wt%, N is 0.0090wt%, P is 0.014 wt%, and the balance is Fe and unavoidable impurities.

The slab casting speed is 5.0m/min, the superheated degree of molten steel is 20-30°C, and an electrical steel slab with an equiaxed crystal ratio of 65% is obtained. The heat preservation temperature of the electrical steel thin slab is 1210°C, and the heat preservation is 2 hours. Then carry out hot rolling, rapid cooling and coiling; hot rolling to 2.2mm, the reduction rate of the last 3 passes of the hot rolling process is 20%, the final rolling temperature is 930 ° C, and the relaxation time after rolling is 50 seconds. Then perform rapid cooling at a cooling rate of 50° C./second to obtain fine and uniform hot-rolled coils with precipitates and structures. In this embodiment, the normalized annealing of the hot-rolled coils is cancelled.

Then cold rolling was performed by the primary cold rolling method, and it was directly cold rolled to 0.3 mm. Then decarburization annealing is carried out, the decarburization annealing temperature is carried out at 890 ° C, carried out in a nitrogen-hydrogen mixed atmosphere, and enters the furnace through humidification, the dew point is 45 ° C, and the time in the furnace is less than 0.9 hours; after coating a magnesium oxide isolation layer, it is formed into a coil.

Finally, high temperature annealing is performed. During high-temperature annealing, heat rapidly to 400°C, heat to 650°C at a heating rate of 10-100°C/hour, then heat to 1190°C at a rate of 20°C/hour, keep at 1190°C for 20 hours, and then cool. During the heating process at 400-1190°C, a protective atmosphere of N ₂ 25%+H ₂ 75% is used, and a protective gas of 100% H ₂ is used in the heat preservation stage.

The chemical composition design of the steel grade in Example 3 is reasonable, the production process is simple, the normalization (annealing) of the hot-rolled sheet can be omitted, and the heating temperature and final high-temperature annealing temperature are low. In Example 3, without adding new equipment, a thin slab process high magnetic induction orientation with (110) (001) high orientation degree secondary recrystallization, high magnetic induction, low iron loss and improved product quality can be manufactured Electrical steel plate. After determination, the chemical composition of the slab and the magnetic properties of the finished product are shown in Table 3:

Table 3 Slab Composition and Finished Magnetic Properties

Claims (3)

1, a kind of manufacturing method of thin slab technology high magnetic induction oriented electrical steel plate, it is characterized in that the thickness of thin slab technology is 50～120mm, thin slab technology is: slab drawing speed is 3～6m/min, molten steel superheat degree is 20-40°C, the equiaxed grain rate of the slab is 30-80%; the chemical composition of the slab is: C is 0.030-0.050wt%, Si is 2.9-3.3wt%, Als is 0.001-0.04wt%, Nb 0.01-0.12wt%, N 0.004-0.012wt%, P <0.015wt%, the rest is Fe and unavoidable impurities, and the inhibitors are AlN and Nb(C, N); first heat the slab to 1150 ～1300℃, keep warm for 2～5 hours, carry out hot rolling, the reduction rate of the last 1～3 passes of the hot rolling process is 10～30%, the final rolling temperature is 800～1050℃, and the relaxation time after rolling is 1 ~600 seconds; then perform rapid cooling and coiling, the cooling rate is 10-200°C/s; then press one or two cold rolling methods: the first cold rolling method is a large cold rolling reduction, and the total reduction rate is ≥80 %; direct decarburization annealing, the decarburization annealing temperature is below 900 ° C, carried out in a nitrogen-hydrogen mixed atmosphere, entering the furnace through humidification, the dew point is 25-55 ° C, and the time in the furnace is less than 1-60 minutes; coated with magnesium oxide After the isolation layer, it is coiled, and finally high-temperature annealing is performed. During the high-temperature annealing period, it is rapidly heated to 400°C, heated to 600°C at a heating rate of 10-100°C/hour, and then heated to 1100-1200°C at a rate of 15-50°C/hour , heat preservation for 15 to 30 hours, and then cooling; in the heating process at 400 to 1200 ° C, a protective atmosphere of N ₂ 25% + H ₂ 75% is used, and a protective gas of 100% H ₂ is used in the heat preservation stage; the second cold rolling method is the first time After cold rolling, intermediate annealing is carried out. The intermediate annealing temperature is 800-1050°C. It is carried out in a nitrogen-hydrogen mixed atmosphere. It enters the furnace through humidification. The dew point is 1-50°C. The time in the furnace is 5-3000 seconds. The rolling reduction rate is 40-70%, the intermediate thickness of the secondary cold rolling method is 0.50-0.90mm, and the thickness is ≤0.30mm after rolling; then decarburization annealing is carried out, and the decarburization annealing temperature is below 900°C. It is carried out in a hydrogen mixed atmosphere, enters the furnace through humidification, the dew point is 25-55°C, and the time in the furnace is less than 1-60 minutes; after coating the magnesium oxide isolation layer, it is formed into a roll, and finally high-temperature annealing is performed. During the high-temperature annealing period, it is rapidly heated to 400 ℃, heated to 600℃ at a heating rate of 10-100℃/hour, then heated to 1100-1200℃ at a speed of 15-50℃/hour, kept for 15-30 hours, and then cooled; in the heating process of 400-1200℃, use The protective atmosphere is N ₂ 25%+H ₂ 75%, and the protective gas 100% H ₂ is used in the heat preservation stage. 2. The method for manufacturing high magnetic induction grain-oriented electrical steel sheet by thin slab process according to claim 1, characterized in that said inhibitor Nb(C, N) is one of NbC, NbN, Nb(CN) or More than one mixed precipitate. 3. The thin slab process high magnetic induction oriented electrical steel sheet manufactured according to the manufacturing method of thin slab process high magnetic induction oriented electrical steel sheet according to any one of claims 1 and 2.