It is very common for Zinc aluminum die casting molds to have soft spots on the surface after heat treatment. This phenomenon will affect the wear resistance of the mold and reduce the service life of the mold.
Cause: There are oxide scales, rust spots and partial decarburization on the surface of the mold before heat treatment. After the mold is quenched and heated, the cooling and quenching medium is improperly selected, and there are too many impurities or aging in the quenching medium.
Preventive measures: Oxide scale and rust spots should be removed before heat treatment of the mold. The mold surface should be properly protected during quenching and heating. Vacuum electric furnaces, salt bath furnaces and protective atmosphere furnaces should be used as much as possible for heating. When the mold is cooled after quenching and heating, a suitable cooling medium should be selected. The cooling medium used for a long time should be filtered frequently or replaced regularly.
