CREEP IN A NI-15CR ALLOY AT LOW STRESSES AND INTERMEDIATE TEMPERATURES

Creep of a Ni-15Cr solid solution alloy has been studied by means of t he helicoid spring specimen technique. The applied stress has varied f rom 0.2 to 5.0 MPa, the testing temperature from 973 to 1123 K and gra in size from 47 to 254 mum. The creep curves exhibit steady state afte r a normal primary stage. The steady state creep rate can be attribute d to the transition from diffusional Coble creep to low temperature Ha rper-Dorn creep controlled by the pipe diffusion.