Abstract: A chromium plating bath which consists essentially of chromic acid and 40-100 g/l of sulfoacetic acid, and which is substantially free of carboxylic acid, fluoride, iodide, bromide and selenium ions, is described herein.

Abstract: What is described herein is an improved method of electroplating an adherent chromium deposit on a chromium substrate. The process is characterized by chemically oxidizing the chromium substrate before starting the electrodeposition of chromium thereon. A suitable chemical oxidizing agent is hydrogen ion, which can be furnished by a dilute acid solution. In this invention, the acid is characterized by being destroyed in the plating bath, if dragged therein. Suitable acids include oxalic and citric acids. The process is applicable to any chromium electroplating bath, including high energy efficient chromium baths, such as HEEF-40 baths, which are presently in commercial use.

Abstract: An activation composition and method for producing chromium electrodeposits having excellent adhesion on both soft and hardened ferrous substrates from high energy efficient chromium baths is described. The activation composition is a solution containing iodate and fluoroborate ions, optionally with cerium ion as a stabilizer. The method includes electrolytically etching the substrate in the activation solution, preceded or followed by reverse etching in chromic acid. The chromium electrodeposit can be carried out effectively to provide the desired adherent deposit from a high energy efficient (HEEF) chromium plating bath.

Abstract: A process for stripping a deposit comprising nickel or a nickel-iron alloy from a substrate metal which comprises immersing the substrate metal with deposit thereon into a stripping bath comprising an aqueous stripping solution comprising chromic acid, utilizing said substrate metal as either or both the anode and cathode of an electrolytic stripping cell and applying an alternating current across the electrodes for a time sufficient to strip the deposit from the substrate metal is disclosed.

Abstract: An improved activation solution is provided for forming adherent chromium electrodeposits on metal substrates from high energy efficient chromium baths. The solution is a substantially neutral alkali metal sulfate solution.

Abstract: Nickel and/or zinc contamination can be handled by increasing the bath's level of tolerance to nickel and zinc, thereby eliminating the need to use precipitants. The instant invention relates to the use in a trivalent chromium bath contaminated with zinc and/or nickel, or an effective amount of a compound represented by the formula R-S, where S is selected from the group consisting of sulfinates, sulfonates, and the acids and soluble salts thereof, and R is either an aliphatic group having from 1 to 6 carbons, or an aromatic or heterocyclic group having up to 12 carbons. Preferably R is an unsaturated hydrocarbon and contains carbon to carbon unsaturation alpha or beta to the sulfur atom.

Abstract: In accordance with certain of its aspects this invention relates to a process and composition for the preparation of an electrodeposit which contains; at least one metal selected from the group consisting of nickel and cobalt or; binary or ternary alloys of the metals selected from nickel, iron and cobalt; which comprises passing current from an anode to a cathode through an aqueous acidic electroplating solution containing at least one member selected from the group consisting of nickel compounds and cobalt compounds and which may additionally contain iron compounds providing nickel, cobalt and iron ions for electrodepositing nickel, cobalt, nickel-cobalt alloys, nickel-iron alloys, cobalt-iron alloys or nickel-iron-cobalt alloys and containing an effective amount of at least one additive; the improvement comprising the presence of 2.times.10.sup.-5 moles per liter to 0.1 moles per liter of an .alpha.

Abstract: In accordance with certain of its aspects, this invention relates to a process for the preparation of an electrodeposit which contains iron and at least one metal selected from the group consisting of nickel and cobalt which comprises passing current from an anode to a cathode through an aqueous plating solution containing an iron compound and at least one member selected from the group consisting of cobalt compounds and nickel compounds providing cobalt or nickel ions for electrodepositing alloys of iron with cobalt and/or nickel and containing in combination an effective amount of:1. at least one member selected from the group of cooperating additives consisting of ascorbic acid, isoascorbic acid, and erythorbic acid; and2. the reaction product of an aromatic sulfinate and an aldehyde or aldehyde derivative; for a time period sufficient to form a sound metal electroplate upon said cathode surface.