Abstract: By using an aqueous solution containing a phosphoric acids or phosphate salts together with carboxylic acids containing at least two carboxyl groups per molecule along with conventional mass finishing, a wide variety of metal parts may be simultaneously deburred, cleaned, and provided with a surface with good resistance to corrosion in humid air. The solution used preferably also contains non-ionic surfactant, corrosion inhibitor, and, for use in hard water areas, a water hardness stabilizer.

Abstract: The metal surfaces are treated with 0.5 to 5 wt. % aqueous solutions (pH value 7.5 to 10.5), in which is contained a synergistic combination--giving a clear solution in water--of corrosion-inhibiting substances. The combination consists of:a. one or more maleic acid mono-n- or -iso-alkylamides with 6 to 14, preferably 8 to 10 C atoms,b. one or more alkalolamines, preferably mono-, di- and/or tri-ethanolamine, andc. complexing phosphonic acids, preferably 1-hydroxy-alkyl-1,1-diphosphonic acid, 1-aminoalkyl-1,1-diphosphonic acid, phosphonocarboxylic acid and/or a phosphonic acid of the formula: ##STR1## Preferred phosphonic acids are 1-hydroxyethane-1,1-diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid and/or nitrilotrimethylene-phosphonic acid.The weight ratio of a:b should be in the solutions 1:0.3 to 1:10, that of a:c, 1:0.01 to 1:0.5. The solutions can contain additionally surfactants, preferably non-ionogenic surfactants in small quantities, also builders, preferably phosphates and/or borates.

Abstract: A method of cleaning metal surfaces comprising spraying a metal surface with an aqueous solution containing(a) at least one soluble salt of a carboxylic acid having 6 to 12 carbon atoms selected from the group consisting of aromatic carboxylic acids, aliphatic carboxylic acids and mixtures thereof,(b) at least one nonionic surface-active compound,(c) at least one quaternary ammonium surface-active compound,where the concentration of the active-substances (a), (b) and (c) in the aqueous solution is from 0.1% to 4% by weight and the weight ratio of (b) to (c) is from 20:1 to 1:1 and the weight ratio of (a) to (b)+(c) is from 20:1 to 1:20, where the pH of the aqueous solution is from 7.5 to 11.