DIN 50940-1:2017-01

This standard specifies a method of measuring the effectiveness of pickling inhibitors. The pickling of metallic surfaces is a chemical, electroless surface treatment method carried out to remove impurities and to obtain a bright, oxide-free surface. The method involves the use of a suitable acid solution or lye (pickle liquor) to remove cast skin, rolling skin, oxide layers, rust or scale. Pickling inhibitors not only reduce acid or lye consumption and loss of material, but also prevents 'excessive' pickling and excessive hydrogen formation.