In the past, wire that had a phosphate-coated surface was used almost exclusively in the production of complex cold extrusion parts. However, besides the advantages in the manufacturing process, there are also disadvantages in the subsequent course of the process, resulting from the phosphate-coated surface. The removal of phosphate coating on the pressed parts, for example, is a very cost-intensive and pollutive procedure.
Moreover, there is a danger of a delta ferrite formation, subject to component type and class of tensile strength, when the pressed parts are subsequently treated thermally. These are only some reasons why the cold compressing industry has attempted to establish wire with a phosphate-free surface as primary material in for a long time. LÜLING has also faced this challenge and has, in close collaboration with customers and scientific institutions, developed a product that fulfils the high standards of cold massive forming.
The know-how of zero-P™ is based, essentially, on three components:
The phosphate coat is now replaced by special coating, consisting of organic and inorganic components. An optimized heat treatment and a special drawing die technology ensure a wire surface, which supports the high quality of forming of our material outstandingly. Thus, zero-P™ is easily removed after the formingprocess as, in contrast to phosphate-treatment, there is no chemical reaction with the basic material.