CREEP TESTING OF STEELS AT VERY HIGH-TEMPERATURES

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 oft en 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 specim en.