Creep properties of 20% cold-worked Hastelloy XR

Abstract

The creep properties of Hastelloy XR, in solution-treated and in 20% cold-worked conditions, were studied at 800, 900 and 1000°C. At 800°C, the steady-state creep rate and rupture ductility decrease, while rupture life increases after cold work to 20%. Although the steady-state creep rate and ductility also decrease at 900°C, the beneficial effect on rupture life disappears. Cold work to 20% enhances creep resistance of this alloy at 800 and 900°C due to a high density of dislocations introduced by the cold work. Rupture life of the 20% cold-worked alloy becomes shorter and the steady-state creep rate larger at 1000°C during creep of the 20% cold-worked alloy. It is emphasized that these cold work effects should be taken into consideration in design and operation of high-temperature structural components of high-temperature gas-cooled reactors.