A production method for decarburizing annealing of grain-oriented silicon steel in the laboratory

Abstract

The present invention discloses a production method for decarburizing annealing of grain-oriented silicon steel in a laboratory, including the following process parameters and steps: 1) Sampling; 2) Shearing the specimen, using a shearing machine to cut the specimen with dimensions of thickness × transverse direction × rolling direction: 0.63 mm × 30 mm × 300 mm, and conducting a laboratory decarburizing annealing test; 3) Decarburizing annealing, using a laboratory decarburizing annealing furnace, with the furnace atmosphere being wet ammonia decomposition gas. The principle of decarburizing annealing is to reduce the carbon content through water vapor in the atmosphere, and the reaction principle is that water vapor reacts with carbon to generate carbon monoxide and hydrogen and discharge them; 4) Analysis of the remaining carbon content; 5) Microstructure analysis. The purpose of the present invention is to provide a production method for decarburizing annealing of grain-oriented silicon steel in a laboratory, which can simulate the decarburizing annealing production of grain-oriented silicon steel in an industrial production line, provide a theoretical basis and empirical data for industrial production trial, shorten the number of on-site commissioning processes, the rejection rate and the second-class product rate of new products of grain-oriented silicon steel, and reduce the manufacturing cost.

Description

Technical Field

[0001] The invention relates to a laboratory decarburization annealing production method for oriented silicon steel. Background Art

[0002] Electrical steel sheets include electrical steel with very low carbon content and silicon content below 0.5% and silicon steel with silicon content of 0.5% to 6.5%, which are mainly used for the iron cores of various motors and transformers. The main indicators to measure the performance of silicon steel are its magnetic properties, namely low core loss and high magnetic induction intensity.

[0003] The production process of grain-oriented silicon steel (CGO) is relatively long. The hot-rolled raw material is first cold-rolled once and then decarburized and annealed to complete the primary recrystallization. The primary recrystallization process of grain-oriented silicon steel can provide favorable texture and conditions for secondary recrystallization. After the cold rolling process, the energy storage of grains with different orientations is different, so the growth order of grains with different orientations is also different during the primary recrystallization process. Therefore, the primary recrystallization annealing process of grain-oriented silicon steel will affect the macro texture type and the final magnetic properties of grain-oriented silicon steel.

[0004] The production and technical level of oriented silicon steel is a powerful reflection of the technical level of a steel enterprise. The pilot test platform is used to carry out laboratory process research on cold rolling and subsequent annealing of oriented silicon steel, complete the decarburization annealing process control under laboratory conditions, and explore the microstructure and macro texture of oriented silicon steel after decarburization annealing, laying a solid theoretical and practical foundation for actual industrial production and application, breaking the technical barriers of process cooperation, and achieving a technological breakthrough in the production trial process of Baosteel's high magnetic induction oriented silicon steel. Summary of the invention

[0005] The purpose of the present invention is to provide a laboratory decarburization annealing production method for oriented silicon steel, which can simulate the decarburization annealing production of oriented silicon steel on an industrial production line, provide a theoretical basis and empirical data for industrial production trials, shorten the number of on-site debugging processes for new oriented silicon steel products and the scrap rate and defective rate, and reduce manufacturing costs.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a laboratory decarburization annealing production method for oriented silicon steel, comprising the following process parameters and steps:

[0008] 1) Sampling

[0009] The thickness of the hot-rolled raw material of oriented silicon steel is 2.6mm, and after pickling, it is cold-rolled once to a thickness of 0.63mm; the sample after cold rolling is taken from the oriented silicon steel cold-rolling production plant, and the size is thickness × rolling direction: 0.63mm × 500mm;

[0010] 2) Shear test specimen

[0011] In order to facilitate the subsequent magnetic property testing needs, a shearing machine was used to cut the sample size into thickness × transverse × rolling direction: 0.63mm × 30mm × 300mm, and a laboratory decarburization annealing test was carried out;

[0012] 3) Decarburization annealing

[0013] A laboratory decarburization annealing heating furnace is used, and the furnace atmosphere is wet ammonia decomposition gas. The principle of decarburization annealing is to reduce the carbon content through water vapor in the atmosphere. The reaction principle is that water vapor reacts with carbon to generate carbon monoxide and hydrogen for discharge;

[0014] 4) Residual carbon analysis

[0015] The decarburized annealed samples were ground and cut by a grinder, and the cut pieces were placed in the analyzer. The LECO-CS600 carbon-sulfur analyzer was used to detect the residual carbon content in the decarburized annealed samples and compare them.

[0016] 5) Microstructure analysis

[0017] The decarburized annealed samples were cut into samples of 10mm×8mm in size; the samples were analyzed along the TD and ND surfaces; the cut samples were mounted on a smooth rectangular gasket with 502 glue, and polished with sandpaper ranging from 100# to 1000#, and mechanically polished after the surface was polished. After no scratches were seen under the microscope, they were corroded, and immediately rinsed with plenty of water and blown dry after a certain period of corrosion, and metallographic photos were taken through a microscope.

[0018] Furthermore, the decarburization annealing temperature was set to 840°C, and the decarburization annealing holding time was set to 5 min.

[0019] Furthermore, the decarburization annealing temperature was set to 840°C, and the decarburization annealing holding time was set to 5 min.

[0020] Furthermore, after etching for 10 seconds, rinse with plenty of water and blow dry immediately.

[0021] Furthermore, the chemical composition of the oriented silicon steel raw material is as follows: C: 0.030-0.040%, Si: 3.00-3.20%, Mn: 0.20-0.23%, P: 0.009-0.014%, S: 0.010-0.013%, Als: 0.012-0.023%, and the rest is Fe and unavoidable impurities.

[0022] Compared with the prior art, the beneficial technical effects of the present invention are:

[0023] The present invention can simulate the decarburization annealing production of oriented silicon steel on an industrial production line, provide a theoretical basis and empirical data for industrial production trials, shorten the number of on-site debugging processes for new oriented silicon steel products, and reduce the scrap rate and defective rate, thereby reducing manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below in conjunction with the accompanying drawings.

[0025] Figure 1 This is the microstructure diagram of the oriented silicon steel after the decarburization annealing experiment in Example 1 of the present invention.

[0026] Figure 2 This is the microstructure diagram of the oriented silicon steel after the decarburization annealing experiment of Example 2 of the present invention.

[0027] Figure 3 This is the microstructure diagram of the oriented silicon steel after the decarburization annealing experiment of Example 3 of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described with reference to the embodiments:

[0029] The chemical composition of the oriented silicon steel raw material is C: 0.030-0.040%, Si: 3.00-3.20%, Mn: 0.20-0.23%, P: 0.009-0.014%, S: 0.010-0.013%, Als: 0.012-0.023%, and the rest is Fe and unavoidable impurities. The thickness of the oriented silicon steel primary cold-rolled sample is 0.63mm, the width is 30mm, and the length is 300mm.

[0030] Example 1

[0031] The present invention proposes a laboratory decarburization annealing method for oriented silicon steel, which includes the following process parameters and steps:

[0032] 1) Sampling

[0033] The thickness of the hot-rolled raw material of oriented silicon steel is 2.6mm, and after pickling, it is cold-rolled once to a thickness of 0.63mm. The sample after cold rolling is taken from the cold-rolled production plant of oriented silicon steel, and the size is thickness × rolling direction: 0.63mm × 500mm.

[0034] 2) Shear test specimen

[0035] In order to facilitate the subsequent magnetic property testing needs, a shearing machine was used to cut samples with the size of thickness × transverse × rolling direction: 0.63mm × 30mm × 300mm for laboratory decarburization annealing tests.

[0036] 3) Decarburization annealing

[0037] A laboratory decarburization annealing heating furnace is used, and the atmosphere in the furnace area is wet ammonia decomposition gas. The principle of decarburization annealing is to reduce the carbon content through water vapor in the atmosphere. The reaction principle is that water vapor reacts with carbon to generate carbon monoxide and hydrogen for discharge.

[0038] The decarburization annealing temperature was set at 840°C and the decarburization annealing holding time was 5 min.

[0039] 4) Residual carbon analysis

[0040] The decarburized annealed samples were ground and cut by a grinder, and the cut pieces were placed in the analyzer. The LECO-CS600 carbon-sulfur analyzer was used to detect the residual carbon content in the decarburized annealed samples and compare them.

[0041] 5) Microstructure analysis

[0042] Cut the decarburized annealed samples into samples of 10mm×8mm. Analyze along the TD and ND surfaces. Use 502 glue to mount the cut samples on a smooth rectangular gasket, and polish them with sandpapers ranging from 100# to 1000#. After the surface is polished, perform mechanical polishing. After no scratches can be seen under the microscope, perform corrosion for about 10s, rinse with plenty of water immediately and blow dry, and take metallographic photos under a microscope.

[0043] Example 2

[0044] The present invention proposes a laboratory decarburization annealing method for oriented silicon steel, which includes the following process parameters and steps:

[0045] 1) Sampling

[0046] The thickness of the hot-rolled raw material of oriented silicon steel is 2.6mm, and after pickling, it is cold-rolled once to a thickness of 0.63mm. The sample after cold rolling is taken from the cold-rolled production plant of oriented silicon steel, and the size is thickness × rolling direction: 0.63mm × 500mm.

[0047] 2) Shear test specimen

[0048] In order to facilitate the subsequent magnetic property testing needs, a shearing machine was used to cut samples with the size of thickness × transverse × rolling direction: 0.63mm × 30mm × 300mm for laboratory decarburization annealing tests.

[0049] 3) Decarburization annealing

[0050] A laboratory decarburization annealing heating furnace is used, and the atmosphere in the furnace area is wet ammonia decomposition gas. The principle of decarburization annealing is to reduce the carbon content through water vapor in the atmosphere. The reaction principle is that water vapor reacts with carbon to generate carbon monoxide and hydrogen for discharge.

[0051] The decarburization annealing temperature was set at 850°C and the decarburization annealing holding time was 5 min.

[0052] 4) Residual carbon analysis

[0053] The decarburized annealed samples were ground and cut by a grinder, and the cut pieces were placed in the analyzer. The LECO-CS600 carbon-sulfur analyzer was used to detect the residual carbon content in the decarburized annealed samples and compare them.

[0054] 5) Microstructure analysis

[0055] Cut the decarburized annealed samples into samples of 10mm×8mm. Analyze along the TD and ND surfaces. Use 502 glue to mount the cut samples on a smooth rectangular gasket, and polish them with sandpapers ranging from 100# to 1000#. After the surface is polished, perform mechanical polishing. After no scratches can be seen under the microscope, perform corrosion for about 10s, rinse with plenty of water immediately and blow dry, and take metallographic photos under a microscope.

[0056] Example 3

[0057] The present invention proposes a laboratory decarburization annealing method for oriented silicon steel, which includes the following process parameters and steps:

[0058] 1) Sampling

[0059] The thickness of the hot-rolled raw material of oriented silicon steel is 2.6mm, and after pickling, it is cold-rolled once to a thickness of 0.63mm. The sample after cold rolling is taken from the cold-rolled production plant of oriented silicon steel, and the size is thickness × rolling direction: 0.63mm × 500mm.

[0060] 2) Shear test specimen

[0061] In order to facilitate the subsequent magnetic property testing needs, a shearing machine was used to cut samples with the size of thickness × transverse × rolling direction: 0.63mm × 30mm × 300mm for laboratory decarburization annealing tests.

[0062] 3) Decarburization annealing

[0063] A laboratory decarburization annealing heating furnace is used, and the atmosphere in the furnace area is wet ammonia decomposition gas. The principle of decarburization annealing is to reduce the carbon content through water vapor in the atmosphere. The reaction principle is that water vapor reacts with carbon to generate carbon monoxide and hydrogen for discharge.

[0064] The decarburization annealing temperature was set at 850°C and the decarburization annealing holding time was 6 min.

[0065] 4) Residual carbon analysis

[0066] The decarburized annealed samples were ground and cut by a grinder, and the cut pieces were placed in the analyzer. The LECO-CS600 carbon-sulfur analyzer was used to detect the residual carbon content in the decarburized annealed samples and compare them.

[0067] 5) Microstructure analysis

[0068] Cut the decarburized annealed samples into samples of 10mm×8mm. Analyze along the TD and ND surfaces. Use 502 glue to mount the cut samples on a smooth rectangular gasket, and polish them with sandpapers ranging from 100# to 1000#. After the surface is polished, mechanical polishing is performed. After no scratches can be seen under the microscope, corrosion is performed for about 10s, and then rinsed with plenty of water and blown dry immediately, and metallographic photos are taken through a microscope.

[0069] Table 1 Data on residual carbon content of implementation examples 1 to 3

[0070] Serial number Residual carbon content (wt%) Implementation Case 1 0.00161 Implementation Example 2 0.00132 Implementation Case 3 0.00177 Standard requirements ≤0.003

[0071] Table 1 shows the residual carbon data of Examples 1 to 3. The residual carbon of oriented silicon steel after decarburization annealing in general industrial production lines is between 0.0022% and 0.0027%. As can be seen from Table 1, the residual carbon of Examples 1 to 3 carried out using the decarburization annealing method provided by the present invention is below 0.002%.

[0072] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A laboratory decarburization annealing production method for oriented silicon steel, Features: The process parameters and steps are as follows: 1) Sampling The thickness of the hot-rolled raw material of oriented silicon steel is 2.6mm, and after pickling, it is cold-rolled once to a thickness of 0.63mm; the sample after cold rolling is taken from the oriented silicon steel cold-rolling production plant, and the size is thickness × rolling direction: 0.63mm × 500mm; 2) Shear test specimen In order to facilitate the subsequent magnetic property testing needs, a shearing machine was used to cut the sample size into thickness × transverse × rolling direction: 0.63mm × 30mm × 300mm, and a laboratory decarburization annealing test was carried out; 3) Decarburization annealing A laboratory decarburization annealing heating furnace is used, and the furnace atmosphere is wet ammonia decomposition gas. The principle of decarburization annealing is to reduce the carbon content through water vapor in the atmosphere. The reaction principle is that water vapor reacts with carbon to generate carbon monoxide and hydrogen for discharge; 4) Residual carbon analysis The decarburized annealed samples were ground and cut by a grinder, and the cut pieces were placed in the analyzer. The LECO-CS600 carbon-sulfur analyzer was used to detect the residual carbon content in the decarburized annealed samples and compare them. 5) Microstructure analysis The decarburized annealed samples were cut into samples of 10mm×8mm in size; the samples were analyzed along the TD and ND surfaces; the cut samples were mounted on a smooth rectangular gasket with 502 glue, and polished with sandpaper ranging from 100# to 1000#, and mechanically polished after the surface was polished. After no scratches were seen under the microscope, they were corroded, and immediately rinsed with plenty of water and blown dry after a certain period of corrosion, and metallographic photos were taken through a microscope.

2. The laboratory decarburization annealing production method for oriented silicon steel according to claim 1, Features: The decarburization annealing temperature is set at 830-850°C, and the decarburization annealing holding time is 4-6 minutes.

3. The laboratory decarburization annealing production method for oriented silicon steel according to claim 1, Features: The decarburization annealing temperature was set at 840°C and the decarburization annealing holding time was 5 min.

4. The laboratory decarburization annealing production method for oriented silicon steel according to claim 1, Features: After 10 seconds of corrosion, rinse with plenty of water and blow dry immediately.

5. The laboratory decarburization annealing production method for oriented silicon steel according to claim 1, Features: The chemical composition of the oriented silicon steel raw material is as follows: C: 0.030-0.040%, Si: 3.00-3.20%, Mn: 0.20-0.23%, P: 0.009-0.014%, S: 0.010-0.013%, Als: 0.012-0.023%, and the rest is Fe and unavoidable impurities.

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