Introduction to Heat Treatment

The aluminum extrusion dies use hot steel as the base material. It needs to go through the heat treatment procedure to improve the hardness and toughness to meet the extrusion conditions of high temperature and high pressure.

Generally, during heat treatment, in order to avoid surface oxidation, resulting in decarbonization after heat treatment , the protective gas for anaerobic will be given (usually would be nitrogen), but there might still be residual oxygen in the process of furnace, so the industry introduced vacuum treatment furnace, in order to effectively inhibit the material surface oxidation, decarbonization, carburization  and other adverse degradation.

                         Pressurized air-cooled vacuum furnace                 Rockwell apparatus 





In the process of heat treatment, 2~4 tempering procedures will be adopted to release the thermal stress and gradually reduce the hardness to enhance the toughness of the die.It is easy to cause poor toughness and brittle cracking of die due to insufficient tempering treatment.

                          Quenching  parameters

                                Tempering parameters