| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a hardening method for a mold capable of suppressing cracks on a product shape surface of the mold; and to provide a method for manufacturing the mold.SOLUTION: Provided is a hardening method for a mold in which the mold which is heated to a hardening temperature in an austenite region is cooled, and the structure of the mold is transformed into martensite. In the cooling process, when a temperature of a region A where the temperature of the rear surface of the mold which is an opposite surface of a product shape surface of the mold is the highest changes through at least a temperature range from a martensite transformation point to 70°C below the martensite transformation point, in a part or the whole of the temperature range, a region B where the temperature of the mold is the highest is cooled to move to the rear surface side of the mold. Preferably, when the temperature of the region B changes through a temperature range from 50°C above the martensitic transformation point to the martensitic transformation point, the region B is cooled at the cooling speed exceeding 3.0°C per minute. Then, in a method for manufacturing the mold, the mold hardened by the hardening method for the mold, the mold is tempered.</p> |
