Fatigue crack propagation of nickel-base superalloys at 650 deg C
The 650 C fatigue crack propagation behavior of two nickel-base superalloys, Rene 95 and Waspaloy, is studied with particular emphasis placed on understanding the roles of creep, environment, and two key grain boundary alloying additions, boron and zirconium. Comparison of air and vacuum data shows the air environment to be detrimental over a wide range of frequencies for both alloys. More in-depth analysis on Rene 95 shows at lower frequencies, such as 0.02 Hz, failure in air occurs by intergranular, environmentally-assisted creep crack growth, while at higher frequencies, up to 5.0 Hz, environmental interactions are still evident but creep effects are minimized. The effect of B and Zr in Waspaloy is found to be important where environmental and/or creep interactions are presented. In those instances, removal of B and Zr dramatically increases crack growth and it is therefore plausible that effective dilution of these elements may explain a previously observed trend in which crack growth rates increase with decreasing grain size.
- Research Organization:
- National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
- OSTI ID:
- 5987375
- Report Number(s):
- N-86-12294; TRN: 86-007437
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of B and Zr on the creep and fatigue crack growth behavior of a Ni-base superalloy
Orientation and temperature dependence of some mechanical properties of the single-crystal nickel-base superalloy Rene N4. II. Low cycle fatigue behavior
Related Subjects
RENE 95
CRACK PROPAGATION
INTERGRANULAR CORROSION
WASPALOY
AIR
BORON ADDITIONS
EXPERIMENTAL DATA
FATIGUE
GRAIN BOUNDARIES
GRAIN SIZE
ZIRCONIUM ADDITIONS
ALLOYS
ALUMINIUM ALLOYS
BORON ALLOYS
CARBON ADDITIONS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COBALT ALLOYS
CORROSION
CRYSTAL STRUCTURE
DATA
FLUIDS
GASES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INFORMATION
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ALLOYS
NUMERICAL DATA
SIZE
TITANIUM ALLOYS
TUNGSTEN ALLOYS
ZIRCONIUM ALLOYS
360103* - Metals & Alloys- Mechanical Properties
360105 - Metals & Alloys- Corrosion & Erosion