JPH0248622B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) Unidirectional silicon steel sheets generally have secondary recrystallized grains of cold-rolled thin sheets that have undergone hot rolling and cold rolling.
It is highly concentrated in the [001] direction (i.e., the Goss direction) to provide desired magnetic properties, and is mainly used in the iron cores of transformers and other electrical equipment, where the magnetic flux density (represented by the B ₁₀ value) is However, due to _past research efforts, it is now possible to
At 0.3mm, B ₁₀ : 1.90T or more, W _17/50 : 1.05W/Kg or less, and at plate thickness 0.23mm, B ₁₀ : 1.89T or more, W _17/50 :
It has become possible to manufacture unidirectional silicon steel sheets with ultra-low core loss of 0.90W/Kg or less.

However, from the standpoint of energy conservation, demands for more stringent reductions in power loss have led to the development of a loss evaluation system, in which the reduction in iron loss is converted into cash and added to the transformer price, especially in Europe and the United States. It has also become established.

In order to meet these severe demands, the inventors have continued their research activities with the aim of improving the properties of unidirectional silicon steel sheets and also reducing iron loss to the utmost.
We tried an innovative method for the final annealing of grain-oriented silicon steel sheets, that is, the operations after finish annealing, especially the coating treatment, and achieved remarkable results in reducing iron loss.After further examination and improvement, we will describe the following. We have clarified the suitability of continuous processing equipment for iron loss reduction of unidirectional silicon steel sheets.

(Prior art) JP-A No. 57-2252, JP-A No. 57-53419, JP-A No. 58-
No. 26405 and No. 58-26406 disclose that the surface of a unidirectional silicon steel sheet after finish annealing is subjected to laser irradiation in a direction substantially perpendicular to the rolling direction to introduce local minute strain. Although it has been disclosed that magnetic domain refinement is used to reduce iron loss,
In this case, even though it is effective in applications where so-called strain-relief annealing is not applied, when such annealing is applied, the local microstrain that has been painstakingly introduced is released during heating and holding, and the magnetic domain width expands, causing the laser irradiation. There is a disadvantage that the effect is lost.

On the other hand, the inventors have previously succeeded in manufacturing an ultra-low iron loss unidirectional silicon steel sheet that does not suffer from characteristic deterioration despite the above-mentioned high-temperature treatment.

That is, after removing the oxides generated on the outer surface of the steel sheet through the final annealing process according to the conventional method for grain-oriented silicon steel sheets, both the front and back surfaces are polished to a mirror-like state, and then ion plating is performed to remove Ti, Zr,
V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni,
The object of the present invention is to form an ultra-thin tensile coating made of at least one selected from nitrides and/or carbides of Al, B, and Si, and oxides of Al, Ni, Cu, W, Si, and Zn.

(Problem to be solved by the invention) Based on the experimental results that led to the above success,
It is an object of the present invention to provide a continuous iron-loss-reducing treatment facility for unidirectional silicon steel sheets, which is to be advantageously adapted on an industrial scale.

(Means for Solving the Problems) The present invention provides an array of electrolytic polishing tanks for mirror-finishing both the front and back surfaces of a steel plate that has undergone a final annealing process according to a conventional method for grain-oriented silicon steel sheets, and a process for mirror-finishing the front and back surfaces of a steel plate by the electrolytic polishing. The steel plate is cleaned in a high vacuum treatment tank having two sets of evaporation sources and ionization electrodes, and the inlet side of this high vacuum treatment tank is used for continuous ion plating treatment on both the front and back sides of the steel plate. This is a continuous treatment facility for reducing iron loss of grain-oriented silicon steel sheets, which is characterized by being equipped with an ultrasonic cleaning tank for preheating, and a preheating and/or ion bombardment treatment facility.

Now, Fig. 1 shows a schematic diagram of continuous treatment equipment that performs mirror polishing treatment after removing oxides on both the front and back surfaces of grain-oriented silicon steel sheets that have undergone final annealing, followed by ion plating treatment. .

In the figure, 1 is a grain-oriented silicon steel sheet coil after removing oxides on the outer surface, 2 is an electrolytic polishing tank array including the following tanks, 3 is a pickling tank, 4 is a cleaning tank, and 5 is a cleaning tank.
No. 1 electrolytic tank, 6 a No. 2 electrolytic tank, 7 a cleaning tank, 8 a drying tank, and 9 loopers provided at the inlet and outlet sides of the electropolishing tank row 2.

Also, 10 is a high vacuum processing tank, 11, 11', 1
1" is a pre-evacuation tank row arranged on the inlet side of the high vacuum processing tank 10, 12 is a high vacuum exhaust system, 13 is a gas inlet, and 14, 14', 14" is a high vacuum processing tank 1.
15 is an evaporation source arranged in upper and lower stages in the high vacuum processing tank 10, 16 is an ionization electrode arranged opposite to each evaporation source 15, and 17 is a preliminary evacuation tank array arranged on the outlet side of the A group of guide rolls for threading is shown. Furthermore, 18 and 19 are ultrasonic cleaning equipment arranged across the pre-evacuation tank rows 11, 11', and 11'' on the entry side, and preliminary ion bombardment processing equipment, and 20 is a winding system after undergoing ion plating processing. The coil shown in FIG.

In addition, 21 in the figure is a shear arranged at important points on the sheet passing route.

As the details of the ultrasonic cleaning equipment 18 are illustrated in Fig. 2, it consists of seven tanks: ultrasonic tanks A and D, rinsing tanks B and E, dehydration tank C, steam tank F, and drying tank G. By cleaning the surface of the mirror-finished steel plate, it helps improve the adhesion to the plate surface.

The preheating ion bombardment processing equipment 20 may be a preheating equipment such as an electron beam, but in addition, Ar or H ₂
Bombardment of ions onto the surface of the steel plate is effective.

(Operation) The electrolytic polishing treatment and the subsequent ion plating treatment on the front and back surfaces of the steel plate are performed in the following order.

The coil 1 of the unidirectional silicon steel sheet that has been wound up after final annealing is first led to the pickling tank 3 through the inlet looper 9 of the electrolytic polishing treatment tank row 2 to remove surface oxides from the steel sheet, and then After cleaning the steel plate by passing it through the cleaning tank 4, electrolytic polishing is performed in the No. 1 and No. 2 electrolytic tanks 5 and 6 to finish the steel plate surface to a mirror finish. It is dried through a drying tank 8.

Next, the steel plate is introduced into the high vacuum processing tank 10 through the exit side looper 9 of the electropolishing processing tank row 2 and the inlet side looper 9' of the high vacuum processing tank 10. After cleaning the plate surface, the high vacuum processing tank 1 is passed through the pre-evacuation tanks 11, 11' and 11, which are gradually pressure-regulated to a high degree of vacuum, toward the processing tank 10 on the inlet side of the high vacuum processing tank 10.
0 vacuum seal is ensured. Then preheating and/or
Alternatively, the surface of the steel plate is preheated to 200 to 500°C in the ion bombardment treatment equipment 20, or further
After the surface of the steel sheet is further cleaned by Ar or H ₂ ion bombardment, the sheet is threaded continuously along a curved threading path formed by a group of threading guide rolls 17 inside the high vacuum processing tank 10. The ion plating process is performed while the plate is being moved along the evaporation sources 15 and the ionization electrodes 16 arranged in the upper and lower two stages in the tank.

In the ion plating process, a trace amount of gas is introduced from the gas inlet 13 while evaporating the molten metal in the evaporation source 15, and in this gas atmosphere, the nitrides and/or carbides and oxides listed above are passed through the ionization electrode 16. A tensile thin film consisting of the above is continuously applied to the surface of the steel plate.

In this case, as is clear from FIG. 1, thin film coating can be applied to both the front and back surfaces of the steel plate.

Although illustration is omitted for melting the metal to serve as the evaporation source 15, any conventionally known device such as an electron beam, a hollow cand, an electrode heating device, etc. may be used, and a film can be effectively formed in a short time. Therefore, a magnetron device may be used that accelerates ions by applying a magnetic field just below the surface of the steel sheet being threaded.

The steel sheet that has been subjected to continuous ion plating treatment during sheet passing as described above is placed in a high vacuum treatment tank 10.
On the outlet side of the processing tank, a differential pumping system is used that passes through preliminary pumping tank rows 14, 14' and 14'', which are divided to have higher vacuum levels closer to the processing tank. Derivation and coating 9'
The coil 18 is wound through the coil 18.

(Effect of the invention) After the mirror polishing treatment of the unidirectional silicon steel sheet, the ion plating treatment including ultrasonic cleaning, preheating and/or ion bombardment is carried out continuously in a single line, especially in the mirror polishing treatment. The subsequent ion plating treatment, which follows careful cleaning, can be carried out quickly before deterioration due to the good surface quality of the mirror surface, so that a tension film can be effectively adhered and formed on the surface of the steel sheet. Combined with the fact that the adhesion is outstanding and excellent, iron loss can be effectively reduced.

This equipment can also be used in a continuous line for mirror polishing and ceramic coating of low-carbon cold-rolled steel sheets and general steel sheets such as stainless steel sheets.

(Example) After finish annealing a unidirectional silicon steel plate (0.23 mm thick), oxides on the surface of the steel plate were removed by pickling, and a coil (approximately 8 tons) was wound and subjected to the continuous treatment shown in Figure 1. A 0.8 μm thick TiN tension coating was formed on both the front and back surfaces of the steel plate by passing it through the equipment at a line speed of 40 m/min. The magnetic properties of the product were as follows.

B ₁₀ = 1.92T, W _17/50 = 0.66W/Kg

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a continuous treatment facility for reducing iron loss of unidirectional silicon steel sheets according to the present invention, and FIG. 2 is a detailed diagram of an ultrasonic cleaning tank. 2... Electrolytic polishing treatment tank row, 10... High vacuum processing tank, 15... Evaporation source, 16... Ionization electrode,
18... Ultrasonic cleaning tank, 20... Preheating and/
Or ion bombardment equipment.

Claims (1)

[Scope of Claims] 1. An array of electrolytic polishing baths for mirror-finishing both the front and back surfaces of a steel plate that has undergone a final annealing process according to a conventional method for grain-oriented silicon steel sheets; and both front and back surfaces of the steel plate that have been mirror-finished by this electropolishing. subjected to continuous ion plating treatment,
A high vacuum processing tank having two sets of evaporation sources and ionization electrodes; and an ultrasonic cleaning tank and preheating and/or ion bombardment processing equipment for cleaning and then preheating the steel plate on the inlet side of the high vacuum processing tank; Continuous processing equipment for reducing iron loss for unidirectional silicon steel sheets, characterized by the following: