The heat treatment processes used on mold steel also influences the selection of appropriate steel materials. Some of the factors to consider are:
- Distortion in heat treatment.
- Safety in hardening.
- Depth of hardening.
- Resistance to decarburization.
Technical data is available for the designer to compare mold steel choices with respect to the factors listed above. Time and money will be wasted when the effects of heat treatments are not considered in the steel material selection.
Stress or distortion can be introduced by machining as well as heat treating. The normal solution to remedy distortion is to relieve the stress with normalizing (see heat treatment processes). Distortion, stress, and cracking can be prevented after heat treatment by tempering.
Proper mold design dictates uniform wall sections to avoid stress, cracking, and hardness variations.