| 摘要 |
A turbine disk for a gas turbine engine differentially heat treated so as to produce a dual property disk. The process is applicable to superalloy disks, and achieves substantially uniform yet different temperatures in the rim and hub of the disk during heat treatment, so as to attain specific and different properties for the rim and hub. The process includes the steps of heat treating the entire disk to achieve a uniform structure having a fine grain size and fine precipitates. A device for heating the rim of the disk is then disposed at the disk's periphery, such that the rim is maintained at a substantially uniform temperature above the gamma prime solvus temperature of the superalloy so as to dissolve gamma prime precipitates present in the rim and cause grain growth in the rim. The hub is thermally insulated from the heating device and cooled with an apparatus that enables the hub to be maintained at a substantially uniform temperature that is below the gamma prime solvus temperature of the superalloy. This apparatus insulates and cools the hub such that a temperature gradient is established in the web portion of the disk between the rim and hub, yet substantially uniform temperatures are maintained in the rim and hub. Thereafter, the disk is quenched and then aged at a temperature sufficient to develop gamma prime precipitates in the rim. The resulting disk exhibits improved resistance to creep in the rim and improved tensile strength and low-cycle fatigue resistance in the hub.
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