Electrical pure iron annealing method

Abstract

The invention relates to an electrical pure iron annealing method. The electrical pure iron annealing method comprises the following steps that S1, an electrical pure iron workpiece is loaded into anannealing furnace of 600 DEG C, and the electrical pure iron workpiece is heated along with the furnace to raise the temperature of the electrical pure iron workpiece to 800 DEG C; S2, after the temperature of the electrical pure iron workpiece rises to 800 DEG C, the electrical pure iron workpiece is heated to 850-950 DEG C at the heating speed not larger than 50 DEG C / h, and heat preservation isconducted for 3.5-5.5 h; S3, after heat preservation, the electrical pure iron workpiece is cooled to 700 DEG C at the cooling speed not larger than 50 DEG C / h, and then the electrical pure iron workpiece is cooled to 500 DEG C along with the furnace; and S4, after the electrical pure iron workpiece is cooled to 500 DEG C, nitrogen is introduced into the furnace, the electrical pure iron workpiece is cooled to 50 DEG C through nitrogen and discharged out of the furnace, and annealing treatment on the electrical pure iron workpiece is completed. By introducing nitrogen, the temperature can bequickly reduced, the deformation degree of the electrical pure iron workpiece is effectively reduced, and the internal stress of the electrical pure iron workpiece is effectively removed.

Description

technical field [0001] The invention relates to the processing of electrical pure iron, in particular to an annealing method for electrical pure iron capable of rapid cooling, effective stress removal and reduced deformation. Background technique [0002] In the field of metal processing, cold working will cause various crystal defects (dislocations, stacking faults, etc.) inside pure iron, and cause internal stress, thereby increasing the difficulty of magnetic domain wall movement, increasing Hc, and reducing the value of μm, such as figure 1 shown in . In order to eliminate these adverse effects, it is necessary to carry out stress relief annealing or recrystallization annealing. The effect of annealing temperature on the magnetic properties is as follows: figure 2 As shown, the high annealing temperature makes the crystal grains coarse, and can eliminate the stress of pure iron materials, which is beneficial to the magnetic permeability. The cooling time is fast, the...

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Problems solved by technology

The effect of annealing temperature on the magnetic properties is as follows: figure 2 As shown, the high annealing temperature makes the crystal grains coarse, and can eliminate the stress of pure iron materials, which is beneficial to the magnetic permeability. The cooling time is fast, the deformation shrinkage is small, the cooling time is slow in thick places, and the deformation shrinkage is large, which leads to serious deformation and shrinkage of electrical pure iron workpieces

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