HEAT TREATMENT OF GRAIN DISPERSION STRENGTHENING

摘要

PURPOSE:To attain satisfactory recrystallization in one direction with a high aspect ratio by uniformly heating an extruded billet of a grain dispersion strengthening superalloy to a specified temp. and applying torsional force to the billet so that plastic strain is produced around an axis of the billet. CONSTITUTION:An extruded billet 1 of a grain dispersion strengthening superalloy is put in a heating furnace or the like having heating coils 2. The billet 1 is uniformly heated to a temp. between the recrystallization temp. of the superalloy and the melting temp. Torsional force F is mechanically applied to the billet 1 in the heated state so that >=30% plastic strain is produced around an axis of the billet 1. The force F is continuously or stepwise applied so as to produce dynamic strain. Thus, satisfactory recrystallization in one direction with a high aspect ratio can simply be attained.