JP3446385B2 - Non-oriented electrical steel sheet with excellent coating adhesion - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor, a generator,
The present invention aims to improve the coating adhesion, particularly, of a non-oriented electrical steel sheet widely used as a core material of a transformer or the like. [0002] Non-oriented electrical steel sheets are also applied to air conditioners and compressor motors of refrigerators.
Demand for electrical steel sheets is also increasing as production of air conditioners and refrigerators is on the rise.
Here, the compressor of the air conditioner or the refrigerator is of a so-called hermetic type, and has a special structure in which a refrigerant such as Freon is pressurized by a motor in the compressor and circulates through a thin tube called a capillary nozzle. Accordingly, the motor in this type of compressor is used in a refrigerant such as Freon, unlike a normal motor. [0003] On the other hand, from the viewpoint of energy saving, electromagnetic steel sheets used for compressor motors are also required to have excellent magnetic properties. In response to this request, JP-B-56-54370 and JP-B-58-3027 disclose trace amounts of Sb and
It has been proposed to contain Sn, and the magnetic properties have been improved. [0004] However, trace amounts of Sb and
The non-oriented electrical steel sheet containing Sn has poor adhesion of the coating formed in order to insulate the steel core between the steel sheet laminations. As a result, the coating powder clogs the capillary nozzle, and as a result, there is a disadvantage that the cooling ability of each device is reduced. [0005] Therefore, an object of the present invention is to provide a method for producing trace amounts of Sb or Sn.
To improve the coating adhesion of a non-oriented electrical steel sheet for hermetic compressors having improved magnetic properties. Means for Solving the Problems The present inventors have proposed Sb and / or
Or we investigated the adhesion of the coating of the non-oriented electrical steel sheet containing Sn, especially the clogging of the capillary nozzle due to the use in Freon, and found that the steel sheet surface
The inventors have found that Sb and / or Sn are concentrated and deteriorate the adhesion of the film, and have completed the present invention. [0007] That is, the present invention relates to the following: C: 0.01 wt% or less, Si: 4.0 wt% or less, Mn: 2.0 wt% or less, Al: 2.0 wt%
% And P: 0.2 wt% or less, and further contains Sb and
One or two types of Sn in total 0.01 wt% or more 0.15
wt%, the composition of the balance is Fe and unavoidable impurities.
This is a non-oriented electrical steel sheet for hermetic compressors with excellent coating adhesion, characterized in that +1/2 Sn is 20 wt% or less. Here, the concentration of Sb and Sn on the surface of the ground iron is defined as the Auger Electron Spectroscopy (hereinafter, referred to as A)
(Indicated as ES) means the concentration of Sb and Sn obtained. Next, the experimental results that led to the present invention will be described in detail. C: 0.003 wt%, Si: 0.6 wt%, Mn: 0.2 wt%, Al: 0.
3 wt%, P: 0.02 wt%, Sb: 0 to 0.15 wt% and Sn:
A slab for non-oriented electrical steel sheets containing 0 to 0.15 wt% was hot-rolled, pickled, and then cold-rolled to a thickness of 0.5 mm. Thereafter, finish annealing at various temperatures from 700 ° C. to 900 ° C., pickling in a 20% H ₃ PO ₃ aqueous solution for 0 seconds to 60 seconds, and then a treating solution mainly composed of dichromic acid and a styrene resin emulsion. Was applied with a roll coater and baked at 300 ° C. to form a semi-organic film having a thickness of 0.4 μm. A motor was manufactured using the non-oriented electrical steel sheet thus obtained as an iron core, and this motor was installed in a hermetic compressor, the compressor was installed in a model refrigerator, and this refrigerator was operated for 500 hours. Then, the clogging amount in the capillary nozzle after operation is evaluated in five stages: 5 : less than 0.05 mg 4 : 0.05 to less than 0.1 mg 3: 0.1 to less than 0.3 mg 2 : 0.3 to less than 0.5 mg 1 : 0.5 mg or more did. First, the results of investigating the effects of the added amounts of Sb and Sn on the clogging of the capillary nozzle are shown in FIG. 1 for Sb and FIG. 2 for Sn. FIG.
From the results shown in (2) and (3), no correlation could be found between the added amounts of Sb and Sn and the clogging of the capillary nozzle. Further, for example, regarding a steel sheet to which Sb is added,
The Sb concentration distribution in the depth direction was investigated. As shown in FIG. 3, the results showed that the concentration of added Sb increased from the inside of the steel sheet toward the surface of the steel, and became the highest on the surface of the steel. The concentration in the length or width direction of the steel plate is uniform. Therefore, Sb and Sb on the surface of the steel plate
The effect of Sn concentration on capillary nozzle clogging was investigated. As shown in FIG. 4 , a clear correlation was observed between the concentrations of Sb and Sn on the surface of the base iron and the clogging of the capillary nozzle. If Sb + 1/2 Sn was 20 wt% or less, the clogging of the capillary nozzle was reduced. Turned out to be minor. Here, the Sb and Sn concentrations on the surface of the base steel were examined for Sb + 1/2 Sn. From the results of the experiment, it is clear that the effect of Sn on the coating adhesion is smaller than that of Sb. Because it became. As described above, from the results shown in FIGS. 1 to 4, first, the cause of the peeling of the coating is due to Sb and / or Sn concentrated on the surface of the base iron, that is, Sb and It has been newly found that the adhesion of the coating is inhibited by the concentration of Sn. In order to obtain excellent film adhesion, that is, a film adhesion that suppresses clogging of the capillary nozzle to an allowable range, the concentration of Sb and Sn on the surface of the base iron and the Sb + 1/2 Sn are suppressed to 20 wt% or less. It was also clear that doing so was effective. The reasons for limiting the constituent elements of the present invention will be described below. First, the composition of components of a non-oriented electrical steel sheet according to the present invention is as follows. C: 0.01 wt% or less C deteriorates magnetic properties due to precipitation of carbides.
It should be 01 wt% or less. On the other hand, if it is less than 10 ppm, the steel sheet becomes brittle, so it is desirable that the content be 10 ppm or more. S: 4.0 wt% or less Si is a useful element for increasing the specific resistance and reducing iron loss, and it is preferable to contain 0.1 wt% or more. However, if the content is excessive, the cold rolling property is impaired, so the content was set to 4.0 wt% or less. Mn: 2.0 wt% or less Mn is also an effective element for increasing the specific resistance, and is 0.1 wt%.
The above is preferably contained. However, if the content is excessive, the magnetic flux density decreases, so the content was set to 2.0 wt% or less. Al: 2.0 wt% or less Al is also an effective element for increasing the specific resistance, and 0.2 wt%
The above is preferably contained. However, if the content is excessive, the magnetic flux density decreases, so the content was set to 2.0 wt% or less. P: 0.2 wt% or less P can be preferably added in an amount of 0.04 wt% or more to improve the punching property. However, if the P content exceeds 0.2 wt%, the cold rolling property deteriorates. [0016] Sb and Sn are added in order to improve the magnetic properties of the product by adding one or two of Sb and Sn in total of 0.01 wt% or more and less than 0.15 wt%. Its content is 0.01
If it is less than wt%, the effect of improving magnetic properties is small, and 0.15%
Addition of not less than wt% has no effect of improving magnetic properties and is economically disadvantageous, so it was made not less than 0.01 wt% and less than 0.15 wt%. On the other hand, as shown in FIG. 4, Sb and Sn are concentrated on the surface of the steel plate to inhibit the adhesion of the coating film, so that the concentration of Sb and Sn on the surface of the steel plate, Sb + 1/2 Sn, is reduced.
It is important to control it to 20 wt% or less. Here, it is considered that the enrichment of Sb and / or Sn on the surface of the base steel proceeds when the steel sheet is kept at a high temperature for a long time, that is, during coiling during hot rolling, hot-rolled sheet annealing or finish annealing. Can be Therefore, in order to suppress this enrichment to a predetermined range,
It is advantageous to carefully perform pickling after hot rolling or finish annealing for a long time, and to perform hot-rolled sheet annealing and finish annealing at a low temperature. This is because by performing pickling for a long time, Sb and Sn concentrated on the steel sheet surface can be removed,
Also, by performing the annealing at a low temperature, the concentration of Sb or Sn on the surface decreases. More specifically, in order to remove the hot-rolled scale, pickling after hot rolling is conventionally performed for 30 S or more in a 30% HCl aqueous solution at 70 ° C. for at least 120 S. Pickling after finish annealing without aging, for example, room temperature 10% H ₃ PO ₃
It is effective to carry out 45S or more in an aqueous solution, and to perform hot-rolled sheet annealing at a temperature of 800 ° C or less for 2 hours or less, and to perform finish annealing at 800 ° C or less and 10S or less. However, it is not necessary to perform all of them, and by appropriately combining them, the Sb + 1 / 2Sn on the surface can be reduced.
It is important that the content be 20 wt% or less. The pickling and annealing are not limited to the above conditions. The electromagnetic steel sheet of the present invention can be manufactured according to a conventional method if the above-mentioned conditions are satisfied. Preferable manufacturing conditions and the reasons for limiting the manufacturing conditions will be described below. That is, after smelting by a normal steelmaking method such as a converter steelmaking method by degassing, a slab is manufactured by a continuous casting or casting-ingot casting method. Thereafter, the slab is hot-rolled, and any of a method of reheating the slab and then hot rolling and a method of directly hot rolling without slab heating can be applied. As a magnetic property, when a particularly high magnetic flux density is required, it is possible to improve the texture by coarsening the crystal grains of the hot-rolled sheet by self-annealing during hot-rolled sheet annealing or winding after hot-rolling. It is valid. As the hot-rolled sheet annealing, any of box annealing and continuous annealing can be applied. Next, after performing a predetermined pickling, cold rolling is performed. The product is formed by either cold rolling once to obtain a product thickness and finish annealing, or by performing cold rolling twice with intermediate annealing and then finish annealing. For the finish annealing, any of the ordinary methods is applied. After the finish annealing, an acid coating is applied if necessary, and then an insulating film is formed. As the main component of the insulating film, a known material such as a phosphate or dichromate is suitable.
In addition, after finish annealing, it is also possible to perform a skin pass rolling at a rolling reduction of 1 to 15% to obtain a semi-processed electromagnetic steel sheet. EXAMPLES Example 1 Steels of various compositions were melted using a converter steelmaking method by degassing, made into continuous cast slabs, and then subjected to hot rolling, and then 70 ° C. and 30% After pickling in an aqueous HCl solution for 240 seconds, cold-rolling to a thickness of 0.5 mm, performing finish annealing at 700 to 900 ° C. × 5 s, and pickling in a 20% H ₃ PO ₃ aqueous solution for 0 to 60 seconds. A treatment liquid mainly composed of dichromic acid and a styrene resin emulsion was applied using a roll coater and baked at 300 ° C. to form a 0.5 μm thick semi-organic coating. A motor was manufactured using the non-oriented electrical steel sheet thus obtained as an iron core, and this motor was installed in a hermetic compressor, and the compressor was installed in a model refrigerator, and this refrigerator was operated for 500 hours. Then, the clogging amount in the capillary nozzle after the operation is
The evaluation was made in the above five stages. The results of the evaluation were evaluated based on the ground iron component of the product, AES
Table 1 shows the measurement results of the Sb and Sn concentrations on the surface of the base iron and the magnetic properties after strain relief annealing at 750 ° C. for 2 hours. From the table, it is found that the addition of Sb and / or Sn in the range of 0.01 to 0.15 wt% improves the magnetic properties, while the Sb + 1/2 on the surface of the base iron is improved.
It can be understood that the clogging of the capillary nozzle was completely eliminated by suppressing Sn to 20 wt% or less. [Table 1] Example 2 Steels of various compositions were melted by using a converter steelmaking method by degassing to form a continuous cast slab, which was then subjected to hot rolling.
800 ° C x 1 hour hot rolled sheet annealing, then 80 ° C 30% HC
l Pickling for 240 seconds in an aqueous solution and then cold rolling for 0.5
mm thickness, and a reduction rate of 5 after finish annealing at 700 to 900 ° C x 10s.
% Skin pass rolling, pickling with a 20% H ₃ PO ₃ aqueous solution for 0 to 60 seconds, applying a treatment solution mainly composed of dichromic acid and a vinyl acetate resin emulsion with a roll coater, and then applying the solution at 300 ° C. After baking, a 0.2 μm thick semi-organic coating was formed. A motor was manufactured using the non-oriented electrical steel sheet thus obtained as an iron core, and this motor was installed in a hermetic compressor, and the compressor was installed in a model refrigerator, and this refrigerator was operated for 500 hours. Then, the clogging amount in the capillary nozzle after the operation is
The evaluation was made in the above five stages. The results of the evaluation were evaluated based on the ground iron component of the product, AES
Table 2 shows the Sb and Sn concentrations on the surface of the base steel and the magnetic properties after strain relief annealing at 750 ° C. for 2 hours. From the table, it is found that the addition of Sb and / or Sn in the range of 0.01 to 0.15 wt% improves the magnetic properties, while the Sb + 1/2 on the surface of the base iron is improved.
It can be understood that the clogging of the capillary nozzle was completely eliminated by suppressing Sn to 20 wt% or less. [Table 2] As described above, according to the present invention, there is provided a film having excellent film adhesion even after strain relief annealing and which does not cause clogging of a capillary nozzle when applied to a closed type compressor. A grain-oriented electrical steel sheet can be provided.
That is, the non-oriented electrical steel sheet of the present invention is particularly suitable for a high-efficiency compressor motor,
It is possible to promote higher efficiency of air conditioners and refrigerators.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing the relationship between the content of Sb and clogging of a capillary nozzle. FIG. 2 is a diagram showing the relationship between the Sn content and clogging of a capillary nozzle. FIG. 3 is a diagram showing the concentration of Sb in a steel sheet depth direction. FIG. 4 is a diagram showing the relationship between the concentration of Sb and Sn on the surface of a base iron and clogging of a capillary nozzle.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-161271 (JP, A) JP-A-4-346621 (JP, A) JP-A-7-54044 (JP, A) JP-A-3-3 274247 (JP, A) JP-A-59-31823 (JP, A) JP-A-6-503609 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C22C 38/00 303 C22C 38/06 C22C 38/60 H01F 1/16

Claims (1)

(57) [Claims] [Claim 1] Including C: 0.01 wt% or less, Si: 4.0 wt% or less, Mn: 2.0 wt% or less, Al: 2.0 wt% or less, and P: 0.2 wt% or less. In addition, any one or two of Sb and Sn are contained in a total amount of 0.01 wt% or more and less than 0.15 wt%, and the composition of the balance is Fe and unavoidable impurities, and the concentration of Sb and Sn on the surface of the ground iron Non-oriented electrical steel sheet for hermetic compressors with excellent film adhesion, characterized in that Sb + 1/2 Sn is 20 wt% or less.