JPH0739631B2 - Equipment for reducing iron loss of unidirectional silicon steel sheets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) Generally, unidirectional silicon steel sheets are produced by subjecting secondary recrystallized grains of a cold rolled thin sheet after hot rolling and cold rolling to (100) [001] orientation. ,
It has a high degree of integration (ie, rubber orientation) with the desired magnetic properties and is mainly used for the iron core of transformers and other electrical equipment, where the magnetic flux density (represented by the B ₁₀ value) is high. Moreover, low iron loss (represented by the W _17/50 value) is required.
Ultra low iron such as B ₁₀ : 1.90T or more at 0.3 mm, W _17/50 : 1.05 W / kg or less, and B ₁₀ : 1.89T or more at W _0.23 mm, W _17/50 : 0.90 W / kg or less Non-oriented grain-oriented silicon steel sheets can also be manufactured.

However, from the viewpoint of energy saving, more stringent demands for reducing power loss have been developed, especially in Europe and the United States, into a loss evaluation (iron loss evaluation) system in which the reduced iron loss is converted and added to the transformer price. It has become established.

In order to meet such severe demands, the inventors have continued their research activities with the aim of improving the characteristics of unidirectional silicon steel sheets and reducing the ultimate loss. The final annealing, that is, the operation after finishing annealing, especially the innovative method for coating treatment was tried, and the result of remarkable iron loss reduction was obtained.
After further study and research, we have clarified the suitability of the iron loss reduction treatment equipment for unidirectional silicon steel sheet described below.

(Prior Art) JP-A-57-2252, 57-53419, 58-26405 and 5
In each of the 8-26406 publications, the surface of the unidirectional silicon steel sheet after finish annealing is subjected to laser irradiation in a direction substantially perpendicular to the rolling direction, and with magnetic domain refinement by the introduction of local minute strain, Although it is disclosed that reduction of loss is disclosed, in this case, even if it is effective in the purpose of not applying so-called strain relief annealing, when the annealing is applied, the local minute strain introduced at the bending angle is maintained while heating. However, there is a disadvantage that the magnetic domain width is expanded and the effect of laser irradiation is lost.

On the other hand, prior to this, in JP-B-52-24499, the surface of the steel sheet after finish annealing of the grain-oriented silicon steel sheet is mirror-finished, or metal plating or an insulating coating is further formed on the mirror-finished surface. A method for producing an ultra-low iron loss unidirectional silicon steel sheet by coating and baking has been proposed.

However, this method of improving iron loss by mirror-finishing is not enough to reduce iron loss in spite of a significant increase in cost for adopting it in a process, and in particular, after applying and baking an insulating coating, which is indispensable after mirror-finishing. Due to the problem of adhesion, it has not been adopted in the current manufacturing process. Japanese Patent Publication No. 56-4150 also proposes a method of vapor-depositing an oxide ceramic thin film after mirror-finishing the surface of a steel sheet. However, this method
This cannot be used in the actual manufacturing process because the steel sheet and the ceramic layer are separated when high temperature annealing of 0 ° C. or higher is applied.

On the other hand, the inventors have succeeded in producing an ultra-low iron loss unidirectional silicon steel sheet without the above disadvantages.

That is, after removing the oxides generated on the outer surface of the steel sheet through the final annealing step that accompanies the conventional method of grain-oriented silicon steel sheet, both front and back surfaces are polished to a mirror surface state, and then a tension film is formed by physical vapor deposition. It is to let.

(Problems to be Solved by the Invention) In industrializing the production of the above-mentioned unidirectional silicon steel sheet, not only the productivity and the product quality but also the equipment cost, running cost, installation space and the like become problems.

That is, in order to improve productivity and product quality, a plurality of electrolytic polishing tanks for mirror-finishing a steel sheet are required, which causes increase in equipment cost, running cost and installation space.

Therefore, it is necessary to provide an iron loss reduction treatment facility for unidirectional silicon steel sheets, which should achieve an advantageous conformity on an industrial scale.
It is the purpose of this invention.

(Means for Solving Problems) The present invention is directed to a pickling tank for removing oxides on both front and back surfaces of a steel sheet that has been subjected to a finish annealing step according to a conventional method for unidirectional silicon steel sheet, and a steel sheet that has been subjected to the pickling step. One-way property characterized by comprising an elastic polishing device and an electrolytic polishing tank for mirror-finishing both front and back surfaces, and a physical vapor deposition device for continuous physical vapor-deposition processing on both front and back surfaces of a mirror-finished steel sheet. This is an iron loss reduction treatment facility for silicon steel sheets.

Now, Fig. 1 shows an example of equipment for reducing the iron loss of the grain-oriented silicon steel sheet which has been subjected to finish annealing.

In the figure, 1 is a unidirectional silicon steel coil that has undergone a finish annealing process, 2 is a welding machine, 3 is a looper, 4 is a pickling tank, 5 is a cleaning tank, 6 is an elastic polishing device, for example, an elastic polishing roll, and 7 is Electropolishing tank, 8 cleaning tank, 9 drying tank, 10 looper, 11
Is a physical vapor deposition device, such as an ion plating device,
12 is a looper, 13 is a shear, and 14 is a tension reel.

The elastic polishing roll 6 is a roll composed of a plurality of rigid abrasives in which abrasive grains are bound to a binder made of a material having extremely low rigidity (for example, polyurethane), and the Shore hardness of the elastic abrasive is 30 to 70. Is preferred.

Further, the ion plating device 11 has, for example, two sets of evaporation sources and ionization electrodes in a high vacuum chamber.

(Operation) The mirror finishing treatment and the subsequent ion plating treatment on the front and back surfaces of the steel sheet are performed in the following order.

For the coil 1 of the unidirectional silicon steel sheet that has undergone finish annealing, continuous steel sheet passing is made possible by first joining the steel sheet ends with a welding machine 2, then through the looper 3, and then to the pickling tank 4. Then, the surface of the steel sheet is cleaned by passing through the cleaning tank 5 to remove the oxides on the surface of the steel sheet, and then the surface of the steel sheet is mirror-finished by the elastic polishing rolls 6, and then the steel sheet is extremely polished in the electrolytic polishing tank 7. The machining-affected layer of the surface layer is removed, and then the surface is washed in the washing tank 8 and passed through the drying tank 9 to be dried.

Next, the steel sheet is passed through the looper 10 and introduced into the ion plating device 11, where, for example, Ti, Zr, V, Nb, T
Ultra-thin consisting of at least one selected from a, Cr, Mo, W, Mn, Co, Ni, Al and Si nitrides and / or carbides and Al, Ni, Cu, W, Si and Zn oxides A tension film is formed, then passed through a looper 12, cut by a shear 13, and wound by a tension reel 14.

Although illustration is omitted for melting the metal to serve as an evaporation source, any conventionally known device such as an electron beam, a hollow cathode, and an electrode heating device may be used, and a film is effectively formed in a short time. For this purpose, a magnetron device may be used in which a magnetic field is applied just below the surface of the steel plate in the threaded plate to accelerate the ions.

Further, when the work-affected layer is not generated on the surface layer of the steel sheet during the mirror finishing treatment by the elastic polishing roll 6, the subsequent electrolytic polishing can be omitted.

(Example) After finish annealing of a unidirectional silicon steel sheet (0.23 mm thick), the annealing separator on the surface of the steel sheet was removed and the coil (about 1.2 tons) was passed through the treatment equipment shown in FIG. Line speed 6m
A TiN tension film having a thickness of 0.6 μm was formed on both front and back surfaces of the steel sheet at a speed of / min. At this time, an elastic polishing material (# 800) having a Shore hardness of 47 using alumina as abrasive grains and polyurethane as a binder was used for the elastic polishing roll, and a phosphoric acid-chromic acid bath was used for the electrolytic polishing tank.

The magnetic properties of the resulting product were as follows.

W _17/50 = 0.70 W / kg, B ₁₀ = 1.92T (Effect of the invention) According to the present invention, iron loss reduction treatment by mirror-finishing the surface of a unidirectional silicon steel sheet and subsequently forming a tension-imparting film Can be industrialized at low cost.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an iron loss reduction treatment facility for unidirectional silicon steel sheets according to the present invention. 1 ... Coil, 2 ... Welder 3,10,12 ... Looper, 4 ... Pickling tank 5,8 ... Cleaning tank, 6 ... Elastic polishing device 7 ... Electropolishing tank, 9 ... Drying tank 11 ... Physical vapor deposition device, 13 ... Shear 14 ... Tension reel

Claims (1)

[Claims] 1. A pickling tank for removing oxides on both front and back surfaces of a steel sheet that has undergone a finish annealing process according to a conventional method for unidirectional silicon steel plates, and a mirror finishing treatment for both front and back surfaces of the steel plate that has undergone the pickling process. Iron loss reduction treatment equipment for unidirectional silicon steel sheets, which comprises an elastic polishing device and an electrolytic polishing tank, and a physical vapor deposition device for continuous physical vapor deposition treatment on both front and back surfaces of a mirror-finished steel sheet. .