The traditional heat treatment process for die-casting molds consists of quenching and tempering, followed by the subsequent development of surface treatment technologies. Given the wide variety of materials used for die-casting molds, applying the same surface treatment techniques and processes to different materials yields varying results. Shikefu proposed substrate pretreatment techniques tailored to specific mold base materials and surface treatment methods; by building upon traditional processes and applying appropriate treatments for different mold materials, mold performance is enhanced and service life extended.
Another avenue for advancing heat treatment technology involves combining traditional heat treatment with advanced surface treatment processes to prolong the service life of die-casting molds. For instance, the NQN process-which integrates the chemical heat treatment method of carbonitriding with conventional quenching and tempering (specifically, a composite strengthening sequence of carbonitriding, quenching, and carbonitriding)-not only achieves high surface hardness but also increases the effective hardening depth, optimizes the hardness gradient of the diffused layer, and improves tempering stability and corrosion resistance. Consequently, die-casting molds benefit from significantly enhanced surface quality and performance while maintaining excellent core properties.