JPS6324035A - Production of steel sheet - Google Patents

Abstract

PURPOSE:To produce a high silicon steel sheet having excellent quality, magnetic characteristics and surface characteristic by removing oxide films from the surface of a steel sheet and forming the film of Si thereon by chemical vapor deposition using a gas contg. a prescribed amt. of SiCl4, then holding the same in a nonoxidizing atmosphere. CONSTITUTION:The steel strip 1 let off from an un-coiler 2 is given adequate tension by tension-control rollers 11, 11 and is passed through a pickling tank 4, by which the oxide films are removed from the surface. The removal of the oxide films is preferably executed until the thickness decreases to <=20Angstrom . After the pickled steel strip 1 is washed in a cleaning tank 5, the steel strip is heated in a heating furnace 6 and Si is deposited by evaporation therein in a vapor deposition furnace 7. The vapor deposition is executed by the chemical vapor deposition treatment carried out at 1,023-1,200 deg.C using a gas for vapor deposition contg. 5-35mol% SiCl4. The steel strip 1 deposited with the Si by evaporation is held at about 1,200 deg.C in a holding furnace 8 in which the nonoxidizing atmosphere is maintained to diffuse the Si into the steel strip 1. The steel strip 1 is then forcibly cooled down to the prescribed temp. in a cooling chamber 9. The resultant high silicon steel strip is coiled on a coiler 3.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a magnetic material with excellent quality, magnetic properties, and surface shape.
The present invention relates to a method of manufacturing a high-silicon steel plate used as an electric iron plate for electromagnetic materials.

[Prior art and its problems]

High-silicon steel sheets are used as electrical steel sheets for electromagnetic materials such as transformers, generators, and electric motors. In high-silicon steel sheets, the higher the silicon content, the lower the iron loss.
, 5 wt.%, it has excellent magnetic properties with magnetostriction of O and the highest magnetic permeability.

A first-order method is known as a method for manufacturing such a high-silicon steel sheet. That is, ordinary steel plate or 4w as the base material plate
By applying chemical vapor deposition treatment (hereinafter referred to as "L deposition treatment") to a low-silicon steel sheet containing silicon of t,% or less at high temperature using a vapor deposition gas containing silicon tetrachloride gas, a steel sheet can be obtained. Silicon is vapor-deposited on the surface of the steel plate, and then the vapor-deposited steel plate is soaked in a non-oxidizing atmosphere to diffuse the vapor-deposited silicon into the steel plate. infiltrate.

However, the above method has the following problems.

A large number of voids called Kirkendall-Zoids occur in the silicon vapor deposited layer of a steel plate subjected to fil vapor deposition treatment. What causes such voids?

It is estimated as follows. That is, since the silicon concentration between the silicon vapor deposited layer and the base material is greatly different, silicon rapidly diffuses into the base material. At this time, since the rate at which iron in the base material diffuses into the vapor deposited layer is slower than the rate at which silicon in the vapor deposited layer diffuses into the base material, the Zides are generated in the deposited layer. Such voids remain even after the diffusion treatment is performed.

If the above-mentioned voids remain in the product, they cause cranking, deteriorating the quality, and also have a negative effect on the magnetic properties.

(2) As a result of the vapor deposition process, 5i02 is generated on the surface of the steel plate, resulting in the product losing its surface gloss, becoming dull gray and having a rough surface.

As a method to prevent the above-mentioned voids from occurring,
JP-A-26263 discloses a method for producing a high silicon steel plate, which comprises the following steps. For a steel plate with a carbon content of 0.15 Wt.% or less as a base material plate, a carbon content of 1200 to 1250
A vapor deposition process is performed at a temperature of 1200 to 1300°C in a non-oxidizing atmosphere.

According to the above-mentioned method, since the vapor deposition treatment is performed at a high temperature of 1200 to 1250°C, the surface layer of the steel plate becomes a semi-molten state. Therefore, voids generated in the deposited layer are fused and disappear.

However, the above-described method has the following problems.

(1) Since the surface layer of the steel plate becomes semi-molten, the thickness of the product tends to be uneven.

(2) Since the surface layer of the steel plate is in a semi-molten state, the vapor deposition process can only be performed on one side at a time, resulting in poor efficiency. Furthermore, the product is likely to be deformed.

(3) When the thickness of the steel plate is thin, not only one surface layer but also
The entire steel plate tends to become semi-molten. Therefore, since the steel plate breaks with a small amount of tension, it is impossible to continuously vapor-deposit a strip-shaped steel plate.

Furthermore, as a method for preventing the above-mentioned voids from occurring, Japanese Patent Publication No. 45-21181 discloses a method for improving the magnetism of an electric iron plate as follows. 11oO to 1250% by weight percentage of silicon tetrachloride gas containing up to 4 on a steel plate without an oxide layer.
A vapor deposition process is performed at a temperature of 1150-1300'C in a non-oxidizing atmosphere, followed by a diffusion process at a temperature of 1150-1300'C.

According to the above method, the content of silicon chloride gas in the deposition gas used for the deposition process is as follows.

Since the weight percentage is 4 or less (moJ fraction is about 1% or less), which is extremely small, the vapor deposition reaction takes place slowly. Therefore, generation of voids can be prevented.

However, the above-described method has the following problems.

(1) Since the vapor deposition reaction is slow, the vapor deposition process takes a long time. Therefore, it is not an industrial method.

(2) When the vapor deposition temperature is 1100 to 1200°C.

It is not possible to completely prevent the occurrence of voids.

(3) When the vapor deposition temperature is 1200 to 1250°C,
As mentioned above, since the surface layer of the steel plate becomes semi-molten,
The plate thickness becomes uneven and deformation occurs in the steel plate.

For this reason, it is used as an electrical iron plate for electromagnetic materials, so that the oxides generated in the vapor deposited layer during the vapor deposition process will not remain in the product and cause the quality, magnetic properties, and surface properties of the product to deteriorate. Although there is a strong desire to develop a method for industrially manufacturing high-silicon steel sheets, such a method has not yet been proposed.

[Purpose of the invention]

Therefore, an object of the present invention is to use it as an electrical iron plate for electromagnetic materials, in which the voids generated in the deposited layer during the deposition process do not remain in the product and cause the quality, magnetic properties, and surface properties of the product to deteriorate. The object of the present invention is to provide a method for industrially manufacturing high-silicon steel sheets.

From the above-mentioned viewpoint, the present inventors have discovered that voids generated in the vapor deposited layer during the vapor deposition process remain in the product.

We conducted intensive research to develop a method for industrially manufacturing high-silicon steel sheets used as electrical iron sheets for electromagnetic materials, without degrading product quality, magnetic properties, and surface properties.

The present inventors first investigated the state of generation of voids after vapor deposition treatment and the reason why the generated voids do not disappear even after diffusion treatment.

Figure 6 shows 5iC of 15% in 1 mol fraction for a steel plate as a base material plate with a thickness of 0.5 g and containing 3 wt of silicon.
Jl! A micrograph showing the metallographic structure of a cross section of a steel plate immediately after being subjected to vapor deposition treatment at a temperature of 1150°C using a vapor deposition gas consisting of + gas and 85% Ar gas (200°C
times). As is clear from FIG. 6, many voids are generated in rows in the silicon vapor deposited layer on both sides of the steel plate.

FIG. 7 shows a steel plate subjected to the above vapor deposition treatment,
Micrograph (200x) showing the metallographic structure of a cross section of a steel plate after diffusion treatment for 1 hour under vacuum at a temperature of 00'C
It is. As can be seen from FIG. 7, the voids generated in the deposited layers on both sides of the steel plate have not disappeared. This void is
Even when the above-mentioned diffusion process is carried out for a long time exceeding one hour, it remains.

The surface gloss and surface roughness of the steel plate subjected to the vapor deposition treatment and diffusion treatment as described above were investigated. The surface gloss was 0.9 as measured by surface emissivity at room temperature,
The surface roughness (RZ) was 3.5 μm and had deteriorated even before the vapor deposition and diffusion treatments.

Next, the iron in the thickness direction of the steel plate immediately after the vapor deposition process.

The bankruptcy distribution of silicon and oxygen was determined by electron diffraction method (EP:V
IA). FIG. 8 shows the measurement results. As can be seen from Figure 8, the silicon concentration of the steel sheet immediately after the vapor deposition process is high in the vapor deposited layer, while the iron concentration is
There is little in the vapor deposited layer. Then, at the interface of the vapor deposited layer, oxygen 3
There is a peak of degree.

The reason why the oxygen concentration peak exists at the interface of the deposited layer is as follows. That is, for example, steel strip is manufactured by hot-rolling a steel billet, then cold-rolling it, and then electrolytically cleaning it, but it is inevitable that the surface of the steel strip will be oxidized by the atmosphere during the manufacturing process. As a result, 30~
An oxide film of 50A is formed on the surface of the steel strip. As a result of vapor deposition treatment of a steel strip having such an oxide film, a peak of oxygen concentration exists at the interface of the vapor deposited layer.

Therefore, an oxide film is also formed on the inner surface of the voids generated in the vapor deposited layer, so that even if a diffusion treatment is performed, the voids will not disappear due to this oxide film. Furthermore, SiO2 is added to the surface of the vapor deposited layer.
As a result, the gloss of the surface is lost, the surface becomes dull gray and the surface becomes rough.

From the above, the present inventors believe that if the oxide film generated on the surface of the steel plate as a base material plate is removed before the vapor deposition process, the surface layer of the steel plate will be in a semi-molten state during the vapor deposition process, or It was discovered that the zide can be eliminated by diffusion treatment without slowing down the deposition reaction.

The present inventors further based on the above-mentioned knowledge.

The residual state of voids was investigated when the oxide film was removed before vapor deposition.

C: 0.005wt,%, A#: 0.05wt
, %, Si: 3. Steel plates containing Owt, % were subjected to hydrofluoric acid pickling with varying degrees of pickling, and a plurality of test pieces with different residual oxide film thicknesses were prepared. After heating this specimen to a temperature of 1150'C, it was heated in a test furnace at a 5iC14':mol fraction of 15%, Ar:m
A vapor deposition process was performed using a vapor deposition gas consisting of 0.01% and 85%, and then a diffusion process was performed by soaking at a temperature of 12000C for 20 minutes.

In this way, the void residual layer (η) of the test piece that had been subjected to the silicon exfoliation treatment consisting of the vapor deposition treatment and the diffusion treatment was investigated.

The void residual rate (η) was calculated as follows.

FIG. 1 is a graph showing the results. As shown in Figure 1, when the thickness of the oxide film on the surface of the test piece becomes 2OA,
The void residual rate is about 1o, and the oxide film thickness is IOA.
Then, the void residual rate becomes about 5%. If the Zide residual rate is 10% or less.

Since there is no practical problem, it has been found that if the thickness of the oxide film is set to 20A or less, the adverse effects of voids can be eliminated.

[Summary of the invention]

This invention was made based on the above-mentioned findings, and includes performing a vapor deposition process on a steel plate as a base material plate at a predetermined temperature using a vapor deposition gas containing a predetermined amount of silicon tetrachloride gas. Silicon is vapor-deposited on the surface of the steel plate, and then the steel plate with silicon vapor-deposited on the surface is soaked at a predetermined temperature in a non-oxidizing atmosphere to diffuse the vapor-deposited silicon into the steel plate, thus, In a method of manufacturing high silicon steel plate.

The content of the silicon tetrachloride gas in the vapor deposition gas is mo
lj fraction is 5 to 35 壬, the predetermined temperature of the vapor deposition treatment is 1023 to 1200 ° C., and the oxide film on the surface of the steel plate is removed before the vapor deposition treatment. It is something that you have.

[Structure of the invention]

In this invention, the composition of the steel plate serving as the base material plate is not particularly limited, but in order to obtain excellent magnetic properties, it is desirable that the steel plate has the composition described below.

(1) Component composition of a steel plate as a base material plate in the case of manufacturing a high silicon steel plate made of 3-6.5% 5i-f;'e gold alloy: Curzan: 0.01wt, % or less, silicon :4wt
,%below.

Manganese: 2wt% or less, and it is desirable that the amount of unavoidable impurities be as small as possible.

[2110-14%Si-3-8%, U-Fe
In the case of manufacturing a high silicon steel plate made of an alloy. Composition of steel plate as base material plate: Carbon: 0.01wt, % or less, Series Y 7
: 4 wt, % or less.

Aluminum: 3-8wt,% Nickel: 4wt,%
Below, manganese: 2 wt, % or less, elements that increase corrosion resistance such as chromium and titanium: 5 wt, 1 or less each, and it is desirable that the amount of unavoidable impurities is as small as possible.

The steel plate as the base material plate may be a cut plate or a copper strip, and the manufacturing method thereof may be a method of hot rolling a steel billet and then cold rolling, or a method of directly casting the steel plate from molten steel. Good too. Furthermore, a grain-oriented silicon steel sheet that has already been given directionality may be used for electric steel sheets.

Note that this is because the thickness of the steel plate decreases during the vapor deposition process.

The steel plate used as the base material plate needs to have a thickness that includes the above-mentioned reduced thickness.

In this invention, the means for removing the oxide film on the surface of the steel plate before the vapor deposition treatment may be pickling or mechanical polishing using a grinder or the like, and the means can be arbitrarily selected. When removing the oxide film by pickling, if the silicon content of the base plate is less than 2wt.4 and so-called selective oxidation of silicon is not a problem, hydrochloric acid pickling is recommended. However, if the silicon content of the steel plate used as the base material plate is 2wt or more, pickling with a strong acid such as hydrofluoric acid is necessary. When removing the oxide film by mechanical polishing using a grinder, etc., the
It is preferable to use a grinding wheel. Using a grindstone that is too rough will result in poor product surface shape.

The above-mentioned removal of the oxide film is preferably performed immediately before the vapor deposition process. Therefore, when manufacturing steel strips on a continuous line, it is preferable to directly connect the oxide film removal equipment and the vapor deposition furnace. If the two cannot be directly connected, the copper strip from which the oxide film has been removed is transferred to the vapor deposition furnace. It is necessary to provide means for licking the copper strip to prevent it from being oxidized by the atmosphere until it is introduced.

Note that it is desirable to completely remove the oxide film, but as mentioned above, if the thickness of the oxide film is 20A or less,
It is possible to substantially eliminate the adverse effects of oxidation.

The content of silicon tetrachloride gas in the deposition gas should be limited within the range of 5 to 35 mol fraction.

That is, if the content of silicon tetrachloride gas is less than 5 h in m01 fraction, the vapor deposition reaction becomes slow, causing a problem that the vapor deposition process requires a long time. On the other hand, when the content of silicon tetrachloride gas exceeds 35 tsumi in m01 fraction.

The vapor deposition temperature is above 10°C, where the silicon vapor deposition layer is thick and the generation of voids is significant.
It should be limited within the range of 23-1200°C. That is,
The reaction formula for vapor deposition treatment on a steel plate is as follows.

5 Fe +5iC14-+F'e3Si +2 Fe
Cl2 In the above reaction formula, 2FeC12 diffuses from the surface of the steel sheet in a gaseous state at a temperature higher than its boiling point of 1023°C. Therefore, the vapor deposition temperature is 1023
At temperatures below °C, 2FeC1k is not dissipated from the surface of the steel plate in a gaseous state, but adheres to the surface of the steel plate in a liquid state.
A problem arises in that the vapor deposition reaction is inhibited.

On the other hand, if the vapor deposition temperature exceeds 1200° C., the surface of the 1 m plate will be in a semi-molten state, resulting in uneven plate thickness and deformation of the steel plate.

FIG. 2 is a block diagram showing an example of an apparatus for carrying out the method of the present invention. As shown in FIG. 2, between the unwinding machine 2 and the winding machine 30, there are a pickling tank 4, a cleaning tank 5, a heating furnace 6, a vapor deposition furnace 7, a soaking furnace 8, and a cooling chamber 9. They are arranged in this order. The pickling tank 4 and the cleaning tank 5 are
are connected to each other. Cleaning tank 5, heating furnace 6, vapor deposition furnace 7
．． The soaking furnace 8 and the cooling chamber 9 are connected to each other by a hood 10. Tension control rollers 11 are provided on the inlet side of the pickling tank 4 and on the outlet side of the cleaning tank 5.

The steel strip 1 going from the unwinding machine 2 to the winding machine 3 is passed through a pickling tank 4,
The cleaning tank 5, heating furnace 6, vapor deposition furnace 7, soaking furnace 8, and cooling chamber 9 are continuously moved. The pickling tank 4 removes the oxide film on the surface of the steel strip 1 using a pickling liquid such as hydrofluoric acid or hydrochloric acid. The cleaning tank 5 removes the pickling liquid adhering to the surface of the steel strip l.

The heating furnace 6 heats the steel strip 1 at a vapor deposition temperature of 1023 to 1
Heat to a temperature of 200'C. The vapor deposition furnace 7 sprays a predetermined amount of vapor deposition gas containing silicon tetrachloride gas from a nozzle toward the surface of the steel strip 1 to vapor-deposit silicon onto the surface of the copper strip 10 . The soaking furnace 8 is a steel strip 1 on which silicon is vapor-deposited.
It is soaked at a temperature of, for example, 1200° C. in a non-oxidizing atmosphere, and silicon deposited on the surface is diffused and permeated into the steel strip 1. The cooling chamber 9 forcibly cools the steel strip 1 to a predetermined temperature.

FIG. 3 is a block diagram showing another example of an apparatus for carrying out the method of the present invention. As shown in FIG. 3, between the unwinding machine 2 and the winding machine 3, there is a polishing chamber 13 provided with a roll-type grinder 12, a cleaning tank 14, a drying furnace 15, a heating furnace 6, and a vapor deposition furnace. 7. Soaking furnace 8 and cooling room 9
are arranged in this order. Polishing chamber 13, cleaning tank 1
4 and the drying oven 15 are connected to each other, and the drying oven]
5. The heating furnace 6, the deposition furnace 7, the soaking furnace 8, and the cooling chamber 9 are connected to each other by a hood 1O.

At the outlet of the cleaning tank 14, a nozzle 16 is provided for injecting a cleaning gas onto both sides of the steel strip 1. Inside the drying oven 15, N2,
A nozzle 17 is provided for injecting a drying gas consisting of an inert gas such as Ar or He, or a mixed gas in which a trace amount of a reducing gas such as H2, CH4, Co, etc. is mixed in the inert gas. There is.

The steel strip 1 going from the unwinding machine 2 to the winding machine 3 is transported to a polishing chamber 13.
, the cleaning tank 14, the drying furnace 15, the heating furnace 6, the vapor deposition furnace 7, the soaking furnace 8, and the cooling chamber 9. The polishing chamber 13 is equipped with a grinder 12.

The surface of the steel strip 1 is polished to remove the oxide film on the surface.

The cleaning tank 14 cleans the surface of the steel strip 1 with the deaerated cleaning liquid. The drying oven 15 dries the surface of the steel strip 1 with drying gas at a temperature of 100 to 200° C. injected from a nozzle 17 . The heating furnace 6, vapor deposition furnace 7, soaking furnace 8, and cooling chamber 9 are as described above.

[Embodiments of the invention]

Example 1 The base material plate contained Q, 8Wt% silicon, and had a thickness of 0.35E'! ! , Itabata 90Ojl&- steel strip A and the same plate thickness 0.35 containing 3,Qwt,% silicon.
u, ElO steel strip B having a plate width of 900 was used. steel strip A,
After removing the oxide film by pickling with hydrochloric acid in the pickling tank 4 using the apparatus shown in FIG. Sample information
Made by kLS. Steel strip B was pickled with hydrochloric acid in the same pickling tank 4 to remove the oxide film, and then subjected to silicon leaching treatment under the same conditions to prepare specimen A2 of the present invention. steel strip B,
Using the apparatus shown in FIG. 3, the υ oxide film was removed by a grinder 12 in a polishing chamber 13, and then a silicon etchant treatment was performed under the same conditions to prepare a specimen K3 of the present invention.

For comparison, steel strips A and B were subjected to silicon exfoliation treatment under the same conditions without removing the oxide film.
and Haruka 2 were prepared.

(1) Heating temperature in heating furnace 6: 1150°C (21 Deposition gas in deposition furnace 7: 5iC114: mo71! fraction: 154 Ar: m01
85% in the separate chamber (3) Diffusion temperature in the soaking furnace 8: 1200°C (4) Diffusion time in the soaking furnace 8 = 20 minutes The silicon content of comparative specimens A1 and A2 was 5.5 wt.

Table 2 shows the surface roughness and oxide film thickness of specimens Nos. 1 to 3 of the present invention and comparative specimens Nos. 1 and 2 before the silicon exfoliation treatment, and the interface roughness after the exfoliation treatment. , void residual rate, surface emissivity and maximum permeability.

As is clear from Table 2, the void residual rates of specimens 1 to 3 of the present invention were extremely low at 5 or 7%, and the surface emissivity and maximum magnetic permeability were extremely excellent. On the other hand, the comparative specimens A1 and 2 had a high residual beid ratio of 75 or 85, and were also inferior in surface emissivity and maximum magnetic permeability.

FIG. 4 is a micrograph showing the metallographic structure of a cross section of the flat specimen 2 of the present invention. As is clear from FIG. 4, almost no voids are observed in the deposited layers on both sides of the copper strip.

Example 2 The above-mentioned steel strip B was used as the base material plate, and after pickling with hydrochloric acid in the pickling tank 4 to remove the oxide film, using the apparatus shown in FIG. Several types of specimens of the present invention were prepared by carrying out the silicon leaching treatment at different times and having different silicon contents within the range of 3.5 to 8.0 wt.%. For comparison, several types of comparative test specimens were prepared under the same conditions as above except that the oxide film was not removed.

The maximum magnetic permeability of the specimen of the present invention and one comparative specimen prepared as described above was measured. Figure 5 is a graph showing the measurement results. In FIG. 5, marks ◯ indicate specimens of the present invention, and marks X indicate specimens for comparison. As is clear from FIG. 5, the maximum magnetic permeability of the specimen of the present invention is
It was significantly superior to the maximum permeability of the comparison specimen.

〔Effect of the invention〕

As detailed above, according to the method of the present invention, voids generated in the vapor deposited layer during the vapor deposition process are eliminated by the diffusion process and do not remain in the product, and 5i02 is generated on the surface of the steel sheet. do not. Therefore, it is possible to produce a high-silicon steel sheet that is used as an electrical steel sheet and has excellent quality, magnetic properties, and surface properties. Furthermore, since the content of silicon tetrachloride gas in the vapor deposition gas is 5 to 35 times in molar fraction, the vapor deposition process can be carried out in a short time, and the vapor deposition temperature is 023 to 1200°C. Therefore, the vapor deposition process can be carried out efficiently without causing non-uniformity in plate thickness or deformation of the steel plate. As described above, the method of the present invention brings about a number of industrially useful effects.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the relationship between the thickness of the oxide film of a steel plate and the void residual rate, Fig. 2 is a block diagram showing an example of an apparatus for carrying out the method of the present invention, and Fig. 3 is the method of the present invention. Block diagram illustrating another example of an apparatus for implementing
The figure is a micrograph showing the metal structure of a cross section of a high-silicon steel plate manufactured by the method of the present invention, Figure 5 is a graph showing the maximum magnetic permeability of the specimen of the present invention and the comparative specimen, and Figure 6 is A micrograph showing the metallographic structure of a cross section of a conventional steel plate immediately after vapor deposition treatment, FIG. It is a graph showing the concentration distribution of silicon and oxygen. In the drawings, 1... Steel strip 2... Unwinding machine 3... Winding machine 4... Pickling tank 5... Washing 41g
6... Heating furnace 7... Vapor deposition furnace 8.
... Soaking furnace 9 ... Cooling chamber lO ... Hood 11 ... Tension control roller 12 ... Grinder 13 ... Polishing chamber 14 ...
Cleaning tank 15...Drying oven 16.17...Nozzle.

Claims (2)

[Claims] (1) A steel plate serving as a base material plate is subjected to chemical vapor deposition treatment at a predetermined temperature using a vapor deposition gas containing a predetermined amount of silicon tetrachloride gas to deposit silicon on the surface of the steel plate, and then , a method for producing a high-silicon steel plate, in which a steel plate on which silicon is vapor-deposited is soaked at a predetermined temperature in a non-oxidizing atmosphere, thereby diffusing the vapor-deposited silicon into the steel plate. , the content of the silicon tetrachloride gas in the vapor deposition gas is
l fraction is 5 to 35%, the predetermined temperature of the chemical vapor deposition treatment is 1023 to 1200 ° C., and the oxide film on the surface of the steel plate is removed before the chemical vapor deposition treatment. A method for producing a high-silicon steel plate. (2) removing the oxide film on the surface of the steel plate so that the thickness of the oxide film is 20 Å or less;
A method for manufacturing a steel plate according to claim (1).