Final report on low-cycle fatigue and creep-fatigue testing of salt-filled alloy 800 specimens

Technical Report · Sat May 01 00:00:00 EDT 1982

DOI:https://doi.org/10.2172/5248956· OSTI ID:5248956

Kaae, J L

Uniaxial low-cycle fatigue and creep-fatigue tests have been carried out on hollow alloy 800 specimens that were either filled with air or with a molten mixture of sodium nitrate, potassium nitrate and an oxidizer. Low-cycle fatigue tests were carried out at 1200/sup 0/F and 650/sup 0/F by cycling the strain continuously between equal mangitude of tensile and compressive values at a rate of 4 x 10/sup -3/sec/sup -1/ until failure. The creep-fatigue tests were carried out at 1200/sup 0/F. The loading cycle differed from that of low-cycle fatigue testing only in the imposition of a hold at the peak compressive strain in each cycle. Cracks always initiated on the inner surface of the hollow specimen, and therefore, corrosive effects on crack propagation and initiation were controlled by the environment within the specimen cavity. In common with tests carried out earlier on steam-filled alloy 800 specimens, at 1200/sup 0/F in the presence of molten salt the heat of alloy 800 with the lower carbon content had a higher fatigue strength than the heat with the higher carbon content even though different heats were used in the two testing programs. The fatigue strength of the two heats of material in the presence of molten salt at 650/sup 0/F were about the same. Tests with air-filled specimens indicated that the presence of the molten salt degraded the fatigue life at 1200/sup 0/F but did not affect the creep fatigue life, while the presence of steam enhanced both the fatigue life and the creep-fatigue life.

• Research Organization: Sandia National Lab. (SNL-CA), Livermore, CA (United States); General Atomics, San Diego, CA (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5248956
• Report Number(s): SAND-82-8182; ON: DE82015730
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
INCOLOY 800
CREEP
FATIGUE
MATERIALS TESTING
POTASSIUM NITRATES
CORROSIVE EFFECTS
SODIUM NITRATES
AIR
CARBON
CRACK PROPAGATION
SERVICE LIFE
STEAM
STRAIN RATE
STRESSES
ALKALI METAL COMPOUNDS
ALLOYS
CHROMIUM ALLOYS
ELEMENTS
FLUIDS
GASES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INCOLOY ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
MECHANICAL PROPERTIES
NICKEL ALLOYS
NITRATES
NITROGEN COMPOUNDS
NONMETALS
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
SODIUM COMPOUNDS
TESTING
140700* - Solar Thermal Power Systems
360105 - Metals & Alloys- Corrosion & Erosion