Nippon Steel Corporation

Mitsubishi Denki Kabushiki Kaisha

Hiroo Goshi

Haruo Komoto

Shigeharu Hamada

Yasuo Shiinoki

Michio Sato

Katsumi Nagano

Ryoichi Naka

Kazutsugu Nakajima

Yukimasa Suemitsu

An apparatus for automatically maintaining plating current density within a predetermined range while controlling plating current to produce a desired plating thickness includes means for energizing only the number of plating cells required to maintain plating current density within the predetermined range. The total plating current required to produce the desired plating thickness is distributed among the energized plating cells. Decreases in the number of energized plating cells is made at speed values which are less by a hysteresis value than speeds at which the number of energized plating cells is increased to avoid instability due to normal speed reading variations.

Plating current automatic compensating apparatus

An apparatus in which plating currents of a plurality of successive plating cells are normally automatically controlled in accordance with line speed to maintain uniform plating thickness, and in which the number of energized plating cells is increased or decreased in accordance with line speed to maintain plating current density within a predetermined range, includes tracking or timing facilities for progressively changing plating currents of plating cells in correspondence with movement of the strip being plated through the cells after the number of energized cells has been increased or decreased so as to reduce plating thickness variation on the portion of the strip within the plating cells at the time of the change in the number of energized cells.

In a process for electrolytically removing metal deposit from a non-plated surface of a single surface-plated metal strip, by bringing, within an electrolytic liquid, a single surface-plated metal strip which serves as an anode plate, into a location at which the non-plated surface of the anode single surface-plated metal strip faces in parallel to and is spaced from a cathode plate, and by applying a principal voltage between the anode metal strip and said cathode plate to electrolytically remove metal deposit from the non-plated surface; whereby undesirable stripping of portions of the plated metal layer in side edge portions of the plated surface of the metal strip is prevented by arranging supplementary anode plates within the electrolytic liquid in such a manner that the supplementary anode plates face in parallel to and are spaced from side edge portions of the plated surface of the anode metal strip, and then, while the principal voltage is applied between the anode metal strip and the cathode plate, a supplementary voltage is applied between the supplementary anode plates and the metal strip, the electric potential of each supplementary anode plate being higher than that of the metal strip.

Process for electrolytically removing metal deposit from a non-plated

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Aichi, Japan

Hiroo Goshi