Heat treatment of hardened steel and plastic molds

1. For moulds with complex shapes, heat treatment should be carried out immediately after rough machining and then finish machining to ensure the minimum deformation during heat treatment. For precision moulds, the deformation should be less than 0.05%.

2. Plastic model cavity surface requirements are very strict, so in the process of quenching and heating to ensure that the cavity surface is not oxidation, not decarbonization, not erosion, not overheating. It should be heated in the protective atmosphere furnace or in the salt bath furnace after strict deoxidization. If the ordinary box-type resistance furnace is used for heating, the protective agent should be coated on the surface of the mold cavity, and the heating speed should be controlled at the same time. Generally, hot bath quenching is preferred, but also can be used in the way of pre-cooling quenching.

3. Tempering should be timely after quenching, tempering temperature should be higher than the working temperature of the mold, tempering time should be sufficient, long and short depending on the mold material and section size, but at least more than 40 ~ 60min.