Light-alloy casting, heat treatment method

摘要

The film boiling state of a refrigerant is maintained for a time longer than in the prior art by time t to lower the nuclear boiling start temperature to a temperature at which the material proof strength of a work exceeds thermal stress, thereby lowering the cooling rate of the work. In addition, by controlling the cooling rate in hardening, the film boiling state of the refrigerant is maintained to a temperature at which the material proof strength exceeds thermal stress, thereby cooling the work at a temperature equal to or higher than the critical cooling temperature. <IMAGE>