Accession Number : ADA136925

Title :   Sustained Load Crack Growth in Inconel 718 Under Non-Isothermal Conditions.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Miller,D L

PDF Url : ADA136925

Report Date : Dec 1983

Pagination or Media Count : 80

Abstract : This investigation found linear cumulative damage modeling applicable to creep crack growth under non-isothermal conditions. The best results are obtained for high crack growth rates produced either by high temperature (above 593C), or by high stress intensities (K greater than 50 MPA square root of m). Except for one test, the linear model predicts conservative growth rates. Constant temperature data are collected for 537, 593, and 648C and presented as da/dt vs K curves. Center-cracked specimens of Inconel 718 are used. The isothermal baseline data are used to predict crack growth rates for the non-isothermal tests using linear cumulative modeling. The predicted creep crack growth rates were within a factor of two of the actual test data. The time-to-failure, predicted for one test, is 56 percent of the actual time to failure.

Descriptors :   *Crack propagation, *Loads(Forces), *Nickel alloys, *Cobalt alloys, Cracking(Fracturing), Cracks, High temperature, Stresses, Intensity, Growth(General), Rates, Models, Predictions, Thermal cycling tests, Creep, Time, Failure, Infrared lamps, Quartz, Halogens, Superalloys, Air Force research, Theses

Subject Categories : Metallurgy and Metallography
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE