12-14-2021, 07:20 AM
Very simply, pickling is an acid bath process to remove the unusable iron oxide scale that forms on hot worked steels as well as other impurities (you may know iron oxide as rust, but there are actually at least 15 other known allotropes of iron oxide). When steels are hot worked, above their recrystallization temperature, oxygen will react with the outside layer of iron and produce a flaky layer of scale. This layer makes the steel difficult to work with and paint.