简介：Themicrostructuralevolutionsofadvanced9-12%Crferrite/martensiteheat-resistantsteelsusedforpowergenerationplantsarereviewedinthisarticle.Despiteofthesmalldifferencesinchemicalcompositions,thesteelssharethesamemicrostructureoftheas-temperedmartensite.Itisthethermalstabilityoftheinitialmicrostructurethatmattersthecreepbehavioroftheseheat-resistantsteels.Themicrostructuralevolutionsinvolvedin9-12%Crferriteheat-resistantsteelsareelabo-rated,including（1）martensiticlathwidening,（2）disappearanceofprioraustenitegrainboundary,（3）emergenceofsubgrains,（4）coarseningofprecipitates,and（5）formationofnewprecipitates,suchasLaves-phaseandZ-phase.Theformerthreemicrostructuralevolutionscouldberetardedbyproperlydisposingthelattertwo.Namelyimprovingthestabilityofprecipitatesandoptimizingtheirsizedistributioncaneffectivelyexertthebeneficialinfluenceofprecipitatesonmicrostructures.Inthissense,themicrostructuralstabilityofthetemperedmartensiteisinfactthestabilityofprecipitatesduringthecreep.Manyattemptshavebeencarriedouttoimprovethemicrostructuralstabilityof9-12%Crsteelsandseveralpromisingheat-resistantsteelshavebeendeveloped.