Creep properties of service-exposed Alloy 625 after re-solution annealing treatment

Creep rupture properties of alloy 625, that has been in service for 60,000 h at 993 K, have been evaluated after subjecting the service-exposed material to re-solution annealing treatment at 1433 K for 1 h. Creep tests were carried out at various temperatures between 923 and 1173 K, and the rupture times varied upto 32,000 h. Iso-stress and Larson–Miller parametric methods were employed to estimate the residual creep rupture life. Creep rupture strength and rupture ductility recovered substantially following re-solution annealing treatment. The variations in rupture life and rupture ductility with creep test variables have been rationalised on the basis of the complex microstructural changes that occurred in the material during creep.