Patent ID: 7396417
Filing Date: 2008-07-08
Classification: B23K,C11D,C23G

Abstract:
1. A process for removing laser scale on a surface of a ferriferous metal part having laser scale thereon by treating the surface of the ferriferous metal part with an aqueous pickling solution comprising: at least one carboxylic acid which is water-soluble and complexes Fe ions from said metal part; at least one salt of at least one carboxylic acid which is water soluble and complexes said Fe ions; at least one fatty amine ethoxylate; wherein the aqueous pickling solution is buffered; wherein said Fe ions enter the aqueous pickling solution and are at least partially complexed; wherein the pH of the aqueous pickling solution is higher than that of said at least one carboxylic acid present; wherein the total concentration of the carboxylic acid and the carboxylic acid salt for pickling is from 2 to 20 wt. %; and wherein the laser scale on the surface of the ferriferous metal part is removed.