Process for hot isostatic pressing of a metal workpiece
OwnerWillard E. Kempinventor
Life of this patent
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Abstract
A process for hot isostatic pressing of a metal workpiece, such as a ferrous casting. The workpiece is heated in a fluidized particulate bed (sand) to a temperature above the plastic range of the metal (e.g. 2000.degree. F.). Then, the workpiece in the unfluidized bed at this temperature is subjected to a superatmospheric gas pressure above 20,000 psi until internal mechanical property changes have occurred. Lastly, the workpiece is removed from the bed and superatmospheric pressure environment for subsequent utilization.
Claims13
A process for treating a metal workpiece comprising the steps of:
- (a) subjecting the workpiece to a fluidized particulate bed at a temperature of a first level until the workpiece throughout reaches substantially this temperature at the first level;
- (b) terminating fluidization of the bed;
- (c) subjecting the workpiece to superatmospheric gas pressure while leaving the workpiece in the bed at a relatively constant temperature of about the first level until pressure and temperature dependent internal structural changes have occurred in the workpiece;
- and
- (d) removing the workpiece from the bed and superatmospheric pressure for subsequent utilization.
In the process for the hot isostatic pressing of a metal workpiece, the improvement comprising the steps of:
- (a) subjecting the workpiece in a particulate bed of the type adapted to be fluidized to a temperature in the plastic range of the metal;
- (b) applying to the workpiece in the particulate bed of a superatmospheric pressure sufficient in magnitude to effect hot isostatic pressing while the workpiece is in the particulate bed at a relatively constant temperature in the plastic range of the metal;
- and
- (c) removing the workpiece from the superatmospheric pressure and the particulate bed for subsequent utilization.
Dependencies are inferred from the claim text.