Effects of the solute concentration on the deformation characteristics of FeMo solid solutions in the power-law creep regime at 1100 K

Abstract

Creep behaviour at 1100 K has been studied in Fe0.5mol.%Mo alloy (4.0–30 MPa) and Fe1.1mol.%Mo alloy (5.0–45 MPa). Steady state creep characteristics have been analysed together with data reported previously for Fe2.1mol.%Mo alloy and results obtained in conventional tensile tests of these materials. The existence of two transitions in the deformation behaviour becomes evident in b.c.c. FeMo solid solutions as in f.c.c. AlMg alloys. Typical class I behaviour can be observed only under the intermediate stress range. The condition of the upper transition is well described by the Cottrell model for the breakaway of the solute atmosphere as in f.c.c. AlMg alloys. The condition of the lower transition has some common features in FeMo and AlMg alloys, though the creep process in the lower stress range has not been well understood.