A More Detailed Look at Pickling and Inhibiting
Pickling is a surface treatment in which a corroded metal substrate is treated with a pickling solution, usually a liquid or gel. This can be done by immersion, spraying or circulation in place (CIP). Pickling products are often acidic and in some cases neutral. Their job is to remove oxides, corrosion, flash rust, weld discolouration and scale from metal surfaces by etching off these contaminants, so that they cannot have a negative influence on, for instance, paint adhesion.
After the water rinse, the active metal will either have to passivate (such as with aluminium or stainless steel) or be coated, in order to protect it from new corrosion. Although the etching step is necessary to remove all contaminants, it has to be controlled to prevent the base metal being attacked by the acid, which reduces strength. BONDERITE® pickling solutions are equipped with suitable inhibitors that ensure the pickling process takes place in a controlled manner. Our inhibitors not only reduce metal loss, but also acid consumption and hydrogen development (shown by bubbles during pickling), which extends bath life.
Inhibitors reduce attacks and impede embrittlement caused by the absorption of hydrogen. BONDERITE® inhibitors are also available as a single product additive and can be added to base pickling liquids such as sulfuric, hydrochloric and phosphoric acid. The use of Bonderite inhibitors has a negligible effect on pickling time and does not impede or reduce contaminant removal.