PURPOSE: To provide the die forging method of high alloy steel which controls the temperature.
CONSTITUTION: In the die forging time by heating the die 1 and the billet 4 composed of high alloy steel of Ni base heat resistance alloy, etc., the heating temperature of the die 1 is set lower than the heating temperature of the billet 4, the ratio is made within the range 0.6-0.8 and the forming is completed while the temperature relation is kept during forging. As compared with the conventional method which heats the die to a comparative low temperature, because the growing of chill layer from the surface part and the generation of inner strain are prevented, the post process of machining, etc., is eliminated, and the yield is good. In the other hand, as compared with the isothermal forging, the heating device for the die is simplified and the heating time can be shortened and together the complicated operation for the large equipment to be used becomes needless.
IWAZAWA HIDEO
YOSHIDA SHIGERU
