To remove films, such as oxides and lubricants, from a metal substrate, mechanical or thermal stress is first applied to the films so as to rupture the film to the substrate. The substrate is then moved through an electrolysis cell having one or more electrode elements of one electrical polarity spaced from the moving substrate defining another electrode element with the opposite polarity. An electrical signal is applied to the electrodes, and the electrical signal flows down to the metal substrate, resulting in an etching or pitting of the surface of the metal substrate. Following the electrolysis cell, the moving substrate is immersed in a cavitation fluid. Energy, either sonic or ultrasonic, is generated and focused onto the moving substrate so that cavitation bubbles are formed in the pitted portions of the metal substrate beneath the film. When the cavitation bubbles expand and collapse, the resulting cavitational shock wave and the microjet action produce a lifting effect on the film relative to the metal substrate.
Method of electrolytically continuously treating a material of stainless steel at a current density of 0.1-3 A/cm.sup.2, wherein the material is passed through one or more electrolytic cells arranged in series. The cells contain an electrolyte selected from sulphuric acid, a salt thereof, phosphoric acid and nitric acid, and the material is passed through the electrolyte between electrodes arranged in series under the influence of a direct current with alternating polarity. The electrodes are arranged alternately anodic and cathodic and every electrode on one side of said material is matched by an electrode of the same polarity on an opposite side of the material, whereby an oxide surface layer with a thickness of at least 1 micrometer is removed from the material to produce a surface conditioning effect.
A process and a system for removing scale from the surface of high-grade steel strip in installations for the production of pickled hot strip and cold strip. The twofold descaling process combines an electrolytic pickling process with and ultrasonic cleaning of the strip surface.
A method and apparatus for cleaning conductive bodies using a basic aqueous disodium phosphate and sodium bicarbonate electrolyte. The outside surfaces of a metallic body is cleaned by placing the body in contact with the electrolyte and flowing DC current from an anode to the body, which forms a cathode. The body may be immersed in the electrolyte or the electrolyte may be sprayed onto the body.
An apparatus for electroplating a rotogravure cylinder out of a plating solution is disclosed. The apparatus includes a plating tank adapted to support the cylinder and to contain a plating solution so that the cylinder is at least partially disposed into the plating solution. The apparatus also includes a non-dissolvable anode at least partially disposed within the plating solution. A current source is electrically connected to the non-dissolvable anode and to the cylinder. An ultrasonic system may be provided to introduce wave energy into the plating solution includes at least one transducer element mountable within the tank and a power generator adapted to provide electrical energy to the transducer element. A holding tank having a circulation pump, a mixing system and heating and cooling elements for the plating solution may be provided.
