Creep Behavior at 500 °C of %Cr-0.5Mo Steel

Abstract

The creep strength of 5Cr-0.5Mo steel was determined at 600 °C and 78–170 MPa, as well as its relation to the microstructural changes during the creep tests. The microstructural characterization showed that the creep tests were conducted under the presence of a mixture of both intergranular and intragranular M7C3 and M23C6 carbides dispersed in the ferrite matrix. The n exponent of Norton–Bailey law suggested that the creep deformation process occurred through the ferrite grains, which conducted to a transgranular ductile- fracture mode after creep testing. The creep strength of this steel is directly related to the precipitation size and volume fraction during the creep test.