RESEARCH ON CREEP AND ON THE STRENGTH OF NONUNIFORMLY HEATED TURBINE DISKS OF ALLOYS, EI-437B AND EI-787,
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO
Pagination or Media Count:
A comparative analysis of the EI-787 Fe-Cr-Ni base alloy and the EI-437B Ni alloy as materials for turbine disks is presented. The experiments were carried out on two series of four disks each diameter 402 mm. Two disks in each quartet had a normal profile and the other two, a lightweight profile one disk in each pair contained eight small diameter 6 mm eccentrically aligned orifices serving as stress concentrators. The strength of the disks was evaluated as a function of the residual deformation arising in connection with creep during tests at normal rotational speed 15,500 r.p.m. during 5 min., 5, 10, 25, 50 hr. stage 1 of tests, as well as a function of time to fracture during increased rotational speed 19,200 r.p.m. stage 2 of tests. In addition, short-time and long-time mechanical properties of both alloys were investigated on specimens cut out from disks and forgings. Findings The strength of normal-profile disks of both alloys is roughly the same, as is the degree of their deformation. Lightweight-profile disks fractured in the presence of smaller loads lower rotational speeds and their deformation reached a greater degree than normal-profile disks this effect was more pronounced for the EI-437B alloy.
- Metallurgy and Metallography
- Jet and Gas Turbine Engines