Creep Testing of Steels at Very High Temperatures

Abstract

This paper describes changes to specimen grips and specimen design in order to creep test steels at temperatures a little below the spalling temperature and at low stresses (long times) where a large amount of oxidation occurs. High ductility and oxidation of a creep specimen often mean that the thermocouples lose contact with the specimen surface and the specimen itself cannot be removed from the grips after testing. The improvements involve the use of corrosion resistant alloys with reasonable high temperature strength for the loading bars and grips, a change in grip design and measuring the temperature inside the specimen.

Non-contact measurements of creep properties of niobium at 1985 °C

“…Therefore, it is of primary importance to know the creep characteristics of new ultra-high-temperature materials. Conventional creep-testing methods, where the specimen and test apparatus are in contact with each other and enclosed in a furnace, are limited to temperatures of typically 1700 °C, and in specialized setups to 2000 °C [22][23][24][25][26][27][28][29][30][31][32]. Desired temperatures for measurements to support some propulsion applications can easily exceed the standard operating temperature for most conventional apparatus.…”