JPH04198467A - Method of continuous pre-treatment of steel strip - Google Patents

Abstract

PURPOSE:To obtain stabilized and high speed pre-treatment of the steel strip by arranging plural electrodes along the running direction of the steel strip in the vacuum chamber and sustaining high current density between electrodes from entering side of the steel strip to outlet side electrode. CONSTITUTION:The plural electrodes 3a, 3b, 3c are disposed along the running direction of the steel strip 2 into the vacuum chamber 1. The lead wires 4a, 4b, 4c are connected to the electrodes 3a, 3b, 3c respectively and each lead wires 4a, 4b, 4c are connected to the conductor roll contact with the steel strip 2 electrically via rectifiers 5a, 5b, 5c. By this, constitution, inside of the vacuum chamber 1 is filled with gaseous Ar atmosphere having prescribed pressure to run the steel strip 2, and voltage is impressed between cathode of the steel strip and anode of the respective electrodes 4a, 4b, 4c to execute glow discharge and to ionize gaseous Ar and the bombardment treatment of the surface of the steel strip is carried out. In this time, current density of inlet side electrode 3a is lowered and pre-treatment is operated with increased current density of electrodes 3b, 3c.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for pre-treating a continuously running strip such as a steel plate by bombardment.

[Prior Art] Generally, on the surface of a steel plate, water and hydrocarbons are adsorbed (physical adsorption), and an oxide film is adsorbed (chemical adsorption). Therefore, if the coating is applied to the steel plate in this state, the adhesion between the steel plate and the coating will decrease due to the adsorption of these particles.

Therefore, when coating a steel plate by vacuum evaporation, ion blating, sputtering, etc. in a vacuum atmosphere, it is necessary to pre-treat the steel plate to remove these shields immediately before coating.

Pretreatment of a continuous steel plate involves applying a voltage between the strip and an electrode placed opposite it to generate a glow discharge, ionizing the argon gas in the atmosphere, and performing ion bombardment treatment on the surface of the steel plate. will be carried out. Conventionally, one electrode is arranged for this treatment, and when pretreatment is performed at high speed (large current), the electrode area is widened to correspond to the copper strip. However, the current situation is that not only the amount of outgas generated from the copper strip and the temperature of the copper strip differ between the input side and the output side of the copper strip, but also the distance between the poles differs due to the catenary of the steel strip, poor centering, etc. be. Furthermore, the sputtering target, which is one of the factors that determines the discharge voltage, changes from the inlet side to the outlet side to a physically adsorbed layer, a chemically adsorbed layer, and a bulk.

As a result, in the case of an electrode having a large area, the discharge characteristics at each part of the electrode are not constant, and stable glow discharge cannot be obtained over the entire surface of the electrode. In other words, there is a problem in that it is easy to transition to spark or arc discharge.

[Technical problem to be solved by the invention] The present invention was made in view of the above circumstances, and its "first objective is to provide a method that can obtain stable glow discharge and perform pretreatment at high speed. It is something to do.

[Means for Solving the Problems] That is, the present invention provides a continuous pretreatment method for a strip in which a voltage is applied to an electrode arranged in a chamber to perform ion bombardment treatment on a strip running in a chamber. , multiple electrodes are arranged along the running direction of the strip, and the power supplied to each electrode is controlled so that the current density increases from the electrode placed on the inlet side of the strip to the electrode placed on the outlet side. This is a method for continuous pretreatment of strips, characterized in that:

[Examples] The present invention will be described below with reference to illustrative examples. The apparatus shown in FIG. 1 includes a strip 2 in a vacuum chamber 1.
and a plurality of electrodes 3a along the running direction of the strip 2.

3b and 3c are arranged. Electrodes 3a, 3b.

Power lines 4a, 4b, and 4c are connected to 3C, respectively.
These current-carrying lines 4a, 4b, and 4c are rectifiers 5a.

It is connected to the conductor roll 6 via 5b and 5c. This conductor roll 6 is in electrical contact with the strip 2.

In this device, 5 X 10-'-5X 1.0-5T
The strip 2 is run in a vacuum chamber 1 with an argon gas atmosphere of orr, and the strip 2 is used as a cathode.
500~ between each electrode 3a, 3b, 3c as an anode
A voltage of about 2000V is applied. By applying voltage,
Strip 2 and electrodes 3a, 3b.

3C, a glow discharge occurs, ionizing argon gas, and the ionized argon gas performs a heart-menting treatment on the surface of the strip. That is, ionized argon gas collides with the strip surface, sputters impurities on the strip surface and the bulk itself, and activates the strip surface.

Here, in the case of a copper strip, an SS material, or a SUS material, there is a chemical adsorption layer of about 200 angstroms on the surface of the copper strip and a physical adsorption layer of about 30 angstroms thereon. And when there is a physical adsorption layer, the sputtering voltage is low. Therefore, the current is concentrated on the input side electrode 3a. However, discharge in the physically adsorbed layer or chemically adsorbed layer is unstable, and when processed at a high current density with this electrode 3, it tends to shift to spark or arc discharge. Therefore, in the present invention, the current density at the input side electrode 3a is lowered to perform stable discharge, and then the current density is increased at the electrode 3b or 3c at the point when the physical adsorption layer or chemical adsorption layer has disappeared to perform high-speed pretreatment. will be carried out. This allows preprocessing to be performed stably and at high speed.

When magnetron electrodes are used, suitable current densities are, for example, 0.5-1 mA/cJ for electrode 3a, 1-2 mA/CJ for electrode 3b, and 1 for electrode 3C.
, 5-3 mA/cJ.

In addition, in the present invention, as shown in FIG. 2, each electrode 3a, 3b
, 3c have variable external resistors 10a, respectively.

10b, 1. oc is installed and connected to the conductor roll 6 through one rectifier 5, each electrode 3a.

The current density can also be adjusted by appropriately controlling the current (or voltage) flowing through 3b and 3c. Further, the number of electrodes is not limited to three as in the embodiment, but may be more than one. Rather than applying a DC voltage between the strip 2 and the electrode,
It can also be applied in combination with an RF power source and a pro-soaking capacitor.

Note that the present invention is applicable even if the strip is a non-ferrous metal (aluminum, titanium, copper, etc.) other than steel, stainless steel, etc. Further, the pretreatment atmosphere gas may be other than argon, for example, hydrogen.

[Effects of the Invention] As explained above, according to the present invention, a plurality of electrodes are arranged and the current density of each electrode is controlled according to the pretreatment situation, so that pretreatment can be performed stably and at high speed. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the method of the present invention, and FIG. 2 is a schematic diagram showing another embodiment of the method of the present invention. ]・Vacuum chamber, 2...Strip, 3a. 3b, 3c...electrode, 4a, 4b, 4c・
= Current-carrying wire, 5.5a, 5b, 5c... Rectifier, 6...
Conductor roll, 10a, 10b, 10cm...variable external resistance, applicant's representative, patent attorney Takehiko Suzue

Claims (1)

[Claims] In a continuous strip pretreatment method in which a voltage is applied to electrodes arranged in a chamber to perform ion bombardment treatment on a strip running in a chamber, a plurality of electrodes are applied along the running direction of the strip. continuous pretreatment of a strip, characterized in that the power supplied to each electrode is controlled so that the current density increases from the electrode placed on the inlet side to the electrode placed on the outlet side of the strip. Method.