Pickling and degreasing agents

Pragolod 930 is a liquid strong acid cleaning agent suitable for degreasing of medium-greased ferrous metals before galvanizing and should be applied by immersion in the running bath diluted with water at ambient or enhanced bath temperature. To ensure the quality of the degreasing and thus equivalent replacement of the current alkaline process before galvanizing, the degreaser is a blend of concentrated inorganic acids (phosphoric and hydrochloric acids) together with non-ionic surfactants, corrosion inhibitors and solubilizators. The aim of the degreasing bath combined with a pickling affect is, however, not to remove all scales and rust from the surface treated but rather the substrate pretreatment convenient for subsequent pickling process in inhibited acids with surfactants contained, without the necessity of the intermediate rinse. As a result, the number of containers for the pre-treatment processes before galvanizing, overall consumption of rinse water as well as the demand for the waste water treatment process are being reduced significantly.

Running conditions of the bath

Pragolod 940 is a solid, acid-based cleaning agent containing amidosulphuric acid suitable for dissolution and removal of mill scales, corrosion products and hydrolysis products left on the surface after alkaline degreasing or pickling in inorganic acids. Further possible use is for the surface activation of copper alloys, especially free-cutting and cast brass containing lead, and is able to dissolve and remove boiling incrustations while the basic metallic material remains intact by the agent. Both pickling adsorption corrosion inhibitors and non-ionic surfactants are contained in the agent. Ways of its application include immersion or ultrasonic-assisted immersion at temperature range 30 – 80°C, bath concentration 1 – 5% and operation times 1 – 60 minutes.

The agent is suitable for dissolution and removal of corrosion products and mill scales left on the metallic surface after the welding operations and, besides, is possible to make the surface treated uniform in appearance. Further use consists in cleaning and removal of the ferritic-based contaminants from the stainless steel surface, which otherwise might induce rust spots creation on it and mar its appearance badly.

In case of pickling with the agent, a preliminary degreasing in suitable degreasing baths (Pragolod 57 N, Pragolod 18 etc.) is demanded first.

The agent contains both surfactants and corrosion inhibitors durable against bath oxidative environment, which are able to reduce a high bath surface tension and prevent overpickling of the material treated.