SURFACE TREATMENT OF DIE STEEL FOR MOLDING PLASTIC

摘要

PURPOSE:To treat the surface of a die for molding plastic to high hardness and to improve the resistance to wear and erosion by plastic by implanting the nitrogen ion which is made cation into the surface of said die. CONSTITUTION:A die for molding to be used in the stage of producing various mechanical parts of plastic reinforced with glass fibers, etc. is manufactured of a steel. Nitrogen ion is implanted into the surface of the die at 150kV acceleration voltage and 45muA/cm2 beam current density in a 1X1017-5X1017 ion/cm2 range in order to prevent deformation in the shape of the die surface as a result of the wear of the die surface by the reinforced plastic or corrosion of the surface by the moisture in the atm. air or the gas emitted from the plastic during molding. The hard nitride layer is easily formed on the die surface by which the resistance to wear and corrosion is improved and the surface wear and corrosion by the effect of the plastic are obviated. The deformation of the die surface is thus prevented.