CN1189420C - Method of producing microwave oven magnetic steel - Google Patents

Abstract

The present invention provides a method for producing magnetic steel for a microwave oven, which comprises the following steps: (1) Fe2O3, SrCO3, CaCO3 and/or Al4(Si4O10)(OH)3 are mixed and presintered, and solid-phase reaction is carried out to generate ferrite phases; (2) the obtained presintered materials are pulverized into powdery materials whose grain size is less than or equal to 7.5 mu m; (3) additive agents are blended in the powdery materials, and material slurry whose grain size is less than or equal to 0.9 mu m is obtained by adding water to the powdery materials and carrying out wet grinding; (4) the material slurry is placed in a magnetic steel mould whose magnetic-field orientation is in oblique distribution relative to a shaft line, and is pressed into annular magnets which are magnetized; (5) blanks which are formed by pressing are sintered in a furnace to obtain the finished products. The magnetic steel for a microwave oven, which is produced by the method of the present invention, has the characteristics of high blank intensity and high compressive strength, satisfies the required magnetic-field strength of the middle working surface of a microwave oven, and is favorable for improving the heating performance of the microwave oven.

Description

A kind of method of producing microwave oven magnetic steel

Technical field

The present invention relates to the production method of microwave oven magnetic steel.

Background technology

The toroidal magnet that uses in the existing microwave oven magnetic mostly is import greatly, and its magnetic field is axial distribution, so intermediate air gap magnetic field, and promptly the magnetic field of working face is not high enough, can not satisfy the particular requirement in the required magnetic field of microwave oven, has influenced the performance of microwave oven.

Summary of the invention

The objective of the invention is to propose a kind of method of producing microwave oven magnetic steel for the performance that improves microwave oven magnetic steel, this method may further comprise the steps:

1) with 84～87% (weight) Fe ₂O ₃, 12～15% (weight) SrCO ₃, 0.2～1.0% (weight) CaCO ₃And/or Al ₄[Si ₄O ₁₀] (OH) ₈Mix,, carry out solid state reaction and generate the ferrite phase 1200 ℃～1400 ℃ following pre-burnings;

2) the pre-imitation frosted glass of above-mentioned gained is broken into granularity≤7.5 μ m powders;

3) one or more addition of C of blending aCO in powder ₃, SrSO ₄, Al ₂O ₃, SiO ₂, H ₃BO ₃, consumption (by weight) is a powder: additive=1: 0.02～0.05, add the slip that water, wet grinding become granularity≤0.9 μ m, and the slip water content is 30～40%;

4) slip is put into magnetic field orientating and be the magnet steel mould that diagonally distributes, at 300～400Kg/cm with respect to axis ²Under the pressure, be pressed into toroidal magnet, and magnetize, magneticstrength 〉=8000 oersteds;

5) blank with compression moulding carried out the kiln sintering, 1100 ℃～1300 ℃ sintering temperature insulations 1～2 hour.

With the microwave oven magnetic steel that the inventive method is produced, its blank density height, ultimate compression strength is good, and can satisfy the strong characteristics in the middle required magnetic field of working face of microwave oven, is beneficial to and improves the microwave oven heating properties.

Embodiment

Following example further specifies the method that the present invention produces microwave oven magnetic steel, and step is as follows:

1) with 85% (weight) Fe ₂O ₃, 14% (weight) SrCO ₃With 0.5% (weight) CaCO ₃, 0.5% (weight) Al ₄[Si ₄O ₁₀] (OH) ₈Mix,, generate the ferrite phase 1300 ℃ of following pre-burnings;

2) the pre-imitation frosted glass of step 1) gained is broken into granularity≤7.5 μ m powders;

3) blending addition of C aCO in powder ₃, consumption (by weight) is a powder: additive=1: 0.03, add the slip that water, wet grinding become granularity≤0.9 μ m, and the slip water content is 35%;

4) slip is put into annular moulding magnet steel mould, studded with non-magnetic alloy in this magnet steel mould, mould has the magnetizing coil that magnetizes outward, imposes on 350Kg/cm ²Pressure, compacting obtains having highdensity molded blank, and feed electric current at magnetizing coil and magnetize, in mould not under the guiding of mu-metal, the magnetic line of force of magnetic conductive loop is with respect to axis diagonally distributes, generally be 40～50 degree angles, can make that like this intermediary magneticstrength is the strongest;

5) blank is placed kiln, got product in 1 hour 1230 ℃ of sintering temperature insulations.

Further precision work is carried out on the surface of product, can be improved product glossiness.

Claims (2)

1. method of producing microwave oven magnetic steel is characterized in that it may further comprise the steps:

1) with 84～87% (weight) Fe ₂O ₃, 12～15% (weight) SrCO ₃, 0.2～1.0% (weight) CaCO ₃And/or Al ₄[Si ₄O ₁₀] (OH) ₈Mix,, carry out solid state reaction and generate the ferrite phase 1200 ℃～1400 ℃ following pre-burnings;

2) the pre-imitation frosted glass of above-mentioned gained is broken into granularity≤7.5 μ m powders;

3) one or more addition of C of blending aCO in powder ₃, SrSO ₄, Al ₂O ₃, SiO ₂, H ₃BO ₃, consumption (by weight) is a powder: additive=1: 0.02～0.05, add the slip that water, wet grinding become granularity≤0.9 μ m, and the slip water content is 30～40%;

4) slip is put into magnetic field orientating and be the magnet steel mould that diagonally distributes, at 300～400Kg/cm with respect to axis ²Under the pressure, be pressed into toroidal magnet, and magnetize, magneticstrength 〉=8000 oersteds;

5) blank with compression moulding carried out the kiln sintering, 1100 ℃～1300 ℃ sintering temperature insulations 1～2 hour.

2. by the described a kind of method of producing microwave oven magnetic steel of claim 1, it is characterized in that it is 40～50 degree that said magnetic field orientating is the angle that diagonally distributes with respect to axis.