Pickling Process Before Cold Drawing

Ⅰ. Brief Introduction

After hot rolling or heat treatment, the steel has a thick layer of iron oxide covering the surface of the steel. Before cold drawing steel, it is necessary to remove this layer of oxide scale to ensure the quality of the cold drawn steel. The iron oxide scale on the surface of steel affects lubrication (for example, during phosphating and saponification, the presence of iron oxide scale can directly affect the precipitation of phosphate and cannot firmly bond with the substrate of steel); On the other hand, during cold drawing, due to the high hardness of the oxide scale, it is easy to cause surface defects such as scratches on the steel surface. At the same time, it can also increase the drawing force and intensify mold wear, resulting in difficulties in drawing and failing to meet the requirements for a smooth surface of cold drawn steel. Removing iron oxide scale during production also facilitates the detection of defects on the surface of steel for cleaning purposes. Therefore, sufficient attention must be paid to the removal of iron oxide scale in the production of cold drawn steel.

At present, the main method for removing iron oxide scale in the production of cold drawn steel is acid washing. Sometimes non acid washing methods are used in production, but only for pre-treatment. The final and most thorough method is to remove the oxide scale through acid washing.

Ⅱ. Customer Case 

Ⅲ. Picture