Electrolysis: processes – compositions used therein – and methods – Electrolytic coating – Coating moving substrate
Patent
1993-06-08
1995-09-12
Valentine, Donald R.
Electrolysis: processes, compositions used therein, and methods
Electrolytic coating
Coating moving substrate
2041445, 204206, 204237, 204269, 204222, 204294, C25D 534, C25D 550, C25D 1700, C25F 106
Patent
active
054494478
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method for pickling, and possibly for degreasing, elongated metal elements, in particular wires, strips and sectional steel, wherein the metal elements are introduced into an electrolyte solution through which an electric current is passed by means of electrodes.
For simplicity of the description given hereinafter, the elongated metal elements will be referred to as "wires", but it will be clear that which is applicable to "wires" is also applicable to other elements, such as strips and sections.
A method for electrochemical pickling is disclosed in European Patent no. 0 209 168.
However, in this prior patent, pickling in a hydrochloric acid solution by applying an electric current requires an alternating current of a relatively high frequency of at least 200 Hertz, which generally requires the use of a frequency converter. In this respect, it has been stated in the introduction of the description of this patent that neither the use of direct current nor the use of alternating current of the electricity mains (50 or 60 Hertz) is applicable.
One of the essential objects of the present invention is, on the one hand, to obviate the drawbacks of the method of European Patent no. 0 209 169, in particular, the necessity for using frequency converter. Another essential object of the present invention is to propose a method that is suitable for any type of electric current, such as direct current and alternating current at the frequency of the electricity mains.
According to the present invention, the elongated metal elements are preferably moved in a substantially continuous manner in their lengthwise direction through at least two successive separate baths containing an aqueous solution of hydrochloric acid and/or a mineral chlorine salt, wherein in each bath there is placed at least one electrode. An electric voltage is applied to these electrodes in such a manner that the polarity of the electrode of one of the baths is always different from the polarity of the electrode of the adjacent bath, wherein the bath are insulated from each other so that the electric current flows between the two adjacent baths mainly via that portion of the elongated metal element moving between two adjacent baths.
The present invention is also directed to a device for performing the above-described method. This device comprises at least two successive baths that each contain a solution of hydrochloric acid and/or a mineral chlorine salt, said baths being electrically insulated from each other and the elongated metal elements moving therebetween. An electrode is placed in each of these baths at a certain distance, preferably beneath the travelling path of the elongated metal elements, wherein one electrode is connected to one of the poles of a low voltage electric current generator, while the electrode of the adjacent bath is connected to the other pole of this generator.
The present invention further relates to a method for continuously galvanizing elongated metal elements, in particular wires, strips and sectional steel, comprising at least a thermal treatment step, a pickling step possible combined with a degreasing step and a step of coating the surface of these elements with a film of zinc, wherein the elongated metal elements are moved in a substantially continuous manner in their lengthwise direction through these steps. The pickling step comprising moving the elements in an electrolyte solution bath, in particular, of a mineral acid.
In practice, the wires to be galvanized generally have a surface coated with two distinct substances, i.e.
In order to obtain good adherence of zinc to the surface of the wires, the oxide and lubricant must be eliminated while limiting the loss of basic metal.
In certain known methods, the surface treatment precedes the thermal treatment. These methods have, however, the drawback in that high glavanizing speeds cannot be obtained, the difficulty is the duration of the oxide reduction during thermal treatment. In this type of method, surface treatment with an aci
REFERENCES:
patent: 2372599 (1945-03-01), Nachtman
patent: 2719820 (1955-10-01), Allen
patent: 2860092 (1958-11-01), Hart et al.
patent: 3338809 (1967-08-01), Stricker
patent: 3722463 (1973-03-01), Kudo et al.
patent: 3914481 (1975-10-01), Bostroem
patent: 4129485 (1978-12-01), Shikata et al.
patent: 4317848 (1982-03-01), Mellorowicz
patent: 4713153 (1987-12-01), Adriaensen et al.
patent: 5069158 (1991-12-01), Rey
Lowenheim, F. A., Electroplating, Jan. 8, 1979, pp. 67-81.
Draht, vol. 33, No. 6, Jun. 1982, pp. 384-387.
Le Four Industriel Belge S.A.
Valentine Donald R.
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