Abstract: Metals to be bonded are drawn from pay-off reels and passed around holding rollers which are grounded cathodes, each roller being partially exposed in an etching chamber having an anode area at least three times the exposed area of the cathode. Each chamber has an inert gas at from 10.sup.-4 to 10.sup.-1 Torr and is subjected to RF power with a frequency from 1 to 50 MHz, which by a magnetic field produced by fixed magnets in the holding roller produces a glow discharge plasma which etches the metal in the chamber. Etched surfaces of the strips are then rolled together in a vacuum of from 10.sup.-6 to 10.sup.-3 Torr and a temperature to 300.degree. C. at a rolling pressure sufficient to effect a thickness reduction from 0.1 to 30%.

Abstract: A method for the pretreatment of tin-free steel which comprises an anodic treatment or an anodic treatment after a cathodic treatment of an acid pickled steel sheet in an alkaline electrolyte with a pH of above 8, said steel sheet consisting of an upper layer of hydrated chromium oxide and a lower layer of metallic chromium. This pretreated tin-free steel has excellent lacquer adhesion after aging in hot water and under retort conditions.

Abstract: A continuous annealing process for producing a soft tin plate and black plate with T - 21/2 or T - 3 tempering properties is attained in a conventional continuous annealing furnace for black plate by the use of a novel steel strip composition.