Microstructural changes in a Ni-base superalloy during service

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Scripta Metallurgica; (USA)

DOI:https://doi.org/10.1016/0036-9748(89)90138-5· OSTI ID:7061931

Ohta, Y; Yoshizawa, H; Nakagawa, Y G ^[1]

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1. Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

This paper reports on the microstructural changes examined for a conventionally cast nickel base superalloy, Mar-M247. In particular, the first and second stage turbine blades in an experimental turbogas power plant were used. TEM observations confirmed significant secondary {gamma}{prime} precipitation in the mid-blade height of the first stage blade. The formation of dislocation net works in the {gamma} phase was evident int he second stage blades. Coarsening of the primary {gamma}{prime} precipitates also occurred in the first stage blades. Creep rupture, tensile, and high cycle fatigue tests were performed for the first stage blades and showed no deterioration in mechanical properties. The temperature of the blades during service was estimated to be between 760{degrees}C and 840{degrees}C. The total operation time at the time the components were removed for study was 548 hours with 146 heat-up/cool-down cycles.

• OSTI ID: 7061931
• Journal Information: Scripta Metallurgica; (USA), Journal Name: Scripta Metallurgica; (USA) Vol. 23:9; ISSN 0036-9748; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104 -- Fossil-Fueled Power Plants-- Components
36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
CRYSTAL STRUCTURE
ELECTRON MICROSCOPY
GAS TURBINE POWER PLANTS
IN-SERVICE INSPECTION
INSPECTION
MECHANICAL PROPERTIES
MICROSCOPY
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
POWER PLANTS
THERMAL CYCLING
TRANSMISSION ELECTRON MICROSCOPY
TURBINE BLADES
VERY HIGH TEMPERATURE