EFFECTS OF AGING TEMPERATURE AND TIME ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AN Fe-BASE SUPERALLOY

The mechanical properties and microstructure of an Fe-base superalloy GH35A have beenexamined after aging at 650—750℃ for 100—10000 h.The tensile strength of the alloychanges no more with aging temperature and the time at room temperature,but the ductilityand impact toughness at room temperature,as well as the stress-rupture life up to 700℃ de-crease slowly during aging up to 10000 h The initiation time to worsen its properties becomesshorter as the aging temperature rises.The variation of the mechanical properties of the alloywas found mainly depending on the formation,morphology,distribution and characteristic ofthe σ-phase precipitation.