Cleaning and depassivating metal surface to be nitrided or carbonitrided

摘要

A process for additional cleaning and depassivation of metal surfaces, to be nitrided or carbonitrided, involves introducing weak environmentally compatible aqueous acid solutions into the treatment chamber during the heat-up phase of the nitriding or carbonitriding treatment. Preferably, the acid is a naturally occurring acid, such as citric acid.