Annealing method of cold-rolled non-oriented electrical steel thin strip

A technology of oriented electrical steel and annealing, which is applied in the direction of manufacturing tools, furnaces, heat treatment equipment, etc., can solve problems such as bell furnace annealing and smoothing process that have not been mentioned, achieve excellent electromagnetic properties, expand application fields, and increase yield Effect

Active Publication Date: 2014-06-25
ANGANG STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The publication number found is CN101269384A "A Method for Manufacturing Cold-Rolled Non-Oriented Silicon Steel Strip", which mainly involves the annealing of the finished product in a box furnace. 2 ; Publication No. CN101935800A "A High-s

Method used

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  • Annealing method of cold-rolled non-oriented electrical steel thin strip

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Experimental program
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Effect test

Embodiment 1

[0012] 1. After normalization, cold rolling to 0.15mm, and the final pass of cold rolling is evenly sprayed with MgO aqueous solution;

[0013] 2. Roll bell annealing after cold rolling, using N 2 +H 2 Protection, N 2 Volume percentage: 30%; H 2 Volume percentage: 70%; heat preservation at 450°C for 5 hours, the purpose is to dry and cure the coating; annealing at 850°C for 12 hours, the purpose is to recrystallize and make the grain more uniform;

[0014] 3. Stretch annealing (concentration is 6% dilute H 2 SO 4 Wash off MgO), stress relief annealing at 650°C to make the best plate shape, tension 0.8KN;

Embodiment 2

[0016] 1. After normalization, it is cold rolled to 0.18mm, and the final pass of cold rolling is uniformly sprayed with MgO aqueous solution;

[0017] 2. Roll bell annealing after cold rolling, using N 2 +H 2 Protection, N 2 Volume percentage: 20%; H 2 Volume percentage: 80%; heat preservation at 420 ° C for 3 hours, the purpose of drying and curing the coating; annealing at 880 ° C for 12 hours, the purpose of recrystallization and more uniform grains;

[0018] 3. Stretch annealing (concentration is 6% dilute H 2 SO 4 Wash off MgO), stress relief annealing at 750°C to make the best plate shape, tension 1.2KN;

Embodiment 3

[0020] 1. After normalization, cold rolling to 0.20mm, and the final pass of cold rolling is evenly sprayed with MgO aqueous solution;

[0021] 2. Roll bell annealing after cold rolling, using N 2 +H 2 Protection, N 2 Volume percentage: 40%; H 2 Volume percentage: 60%; heat preservation at 480°C for 7 hours, for drying and curing the coating; annealing at 920°C for 12 hours, for recrystallization and more uniform grains;

[0022] 3. Stretch annealing (concentration is 6% dilute H 2 SO 4 Wash off MgO), stress relief annealing at 850°C to make the best plate shape, tension 1.5KN;

[0023] The cold-rolled non-oriented electrical steel thin strip obtained according to the above-mentioned process has no oxidation on the surface of the steel plate, flat shape, and the same plate difference is ≤ 10 μm. The electromagnetic properties are as follows:

[0024]

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Abstract

The invention provides an annealing method of cold-rolled non-oriented electrical steel thin strips, which comprises the following steps: 1) performing normalized acid pickling, then performing cold rolling to reach a thickness of 0.15-0.20 mm, uniformly spraying a MgO aqueous solution on a steel plate surface in a cold rolling final finished product pass process; 2) after cold rolling, performing cover annealing by coils under the protection of N2+H2, wherein the volume percent of N2 is 10%-90% and the volume percent of H2 is 10%-90%, performing heat preservation at 400-500 DEG C for 2-10 hours, then performing recrystallization annealing at 850-1000 DEG C for 8-20 hours; 3) washing off the MgO coating with 3%-8% diluted H2SO4 before stretching annealing, performing stress-relieving annealing at 500-900 DEG C, and applying tension force which is controlled to be 0.8-5 KN. The method of the invention adopts cover furnace annealing, and performs a stretching flattening process after annealing, which not only obtains excellent electromagnetic performance, but also ensures good plate shape, greatly increases the yield, reduces strip breaking, and increases the yield by 10%-20%. The method of the invention is widely applicable to variable frequency motors, and extends the application field of electrical steel.

Description

technical field [0001] The invention relates to a production method of cold-rolled non-oriented electrical steel thin strip, in particular to an annealing method of cold-rolled non-oriented electrical steel thin strip. Background technique [0002] With the wide application of frequency conversion energy-saving technology, the thickness specification of cold-rolled non-oriented silicon steel products decreases from 0.35mm to 0.30mm, 0.25mm, 0.20mm, 0.15mm to ultra-thin strip varieties. The thinner the finished product is, the more frequently the strip is interrupted during the continuous annealing process. , The finished product rate and production efficiency are low, and the production cost is greatly increased, which brings difficulties to production. [0003] At present, although bell furnace annealing is widely used in cold-rolled non-oriented silicon steel products with conventional thickness, it is rarely used in the production of non-oriented silicon steel thin strips...

Claims

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Application Information

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IPC IPC(8): C21D9/52C21D8/02C21D1/26C22C38/06
Inventor 高振宇陈春梅张智义金文旭李文权罗理李亚东李元华张仁波刘文鹏
Owner ANGANG STEEL CO LTD
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