Plastic mold heat treatment
1) There is severe network carbide segregation in the mold material.
2) There is mechanical processing or cold plastic stress in the mold.
3) Improper heat treatment operation of the mold (heating or cooling too fast, improper quenching medium selection, cooling temperature too low, cooling time too long, etc.)
4) The shape of the mold is complex, the thickness is uneven, with sharp corners and thin threaded holes, etc., so that the thermal stress and tissue stress remain too large.
5) If the heating temperature is too high during the quenching process of the plastic mold, it will cause overheating or overburning.
6) After the mold is quenched, the tempering is not timely or the tempering holding time is insufficient.
7) When the mold is reworked and quenched, it is heated and quenched again without intermediate annealing.
8) If the mold is heat-treated, the grinding process is improper.
9) During EDM after heat treatment of the mold, high tensile stress and micro cracks exist in the hardened layer.