Effect of Stress Variation on Creep of a Super Alloy at Elevated Temperatures

Item

Title
Effect of Stress Variation on Creep of a Super Alloy at Elevated Temperatures
Index Abstract
Not Available
Photo Quality
Incomplete
Report Number
ML TDR 64-166
Index Price
$0.00
Report Availability
Full text available by request
Creator
Koterazawa, Ryoichi
Date
1964
Abstract
An investigation was conducted to evaluate the effect of cyclic stress on the creep of a super alloy at elevated temperature. Special attention was given to the frequency effect, and experiments were carried out for a wide range of frequencies, from one cycle per day to 300 cycles per minute, where test data are lacking. Results of experiments showed that there is a relatively narrow transient range of frequencies where the effect of frequency is large and that this transient range shifts quite regularly with the change of stress and temperature, a shift to a higher frequency is caused by higher stress level, lower stress ratio or higher temperature. As expected, the strengthening of material by cyclic stress was found to be an important controlling factor of this phenomenon. However, another factor, recovery effect, was found to be more significant. Some deteriorating of the material was observed in the case where the rest period is much larger than the loading period. Also, cycle dependent fatigue damage was observed in the case of high alternating stress at high frequency.
Extent
64
Corporate Author
University of Minnesota
Laboratory
AF Materials Laboratory
Identifier
AD0603058
Contract
AF 33(657)-7453
Distribution Conflict
No
Access Rights
OTS
Distribution Classification
1
DTIC Record Exists
No
DoD Project
7351 - Metallic Materials
DoD Task
735106 - Behavior of Metals
Date Issued
1964-06
Type
report
Provenance
Lockheed Martin Missiles & Fire Control
Format
64 pages ; 28 cm.