Ageing of forged superaustenitic stainless steel: Precipitate phases and mechanical properties

► Solutionizing of 1250 °C and ageing of 500-1000 °C was done for hot forged SASS. ► Strength and toughness increased by 25% on hot forged than the cast SASS. ► Amounts of precipitates after ageing were evaluated by thermo-calc. ► Sigma forms from chi at 900 °C and contains constant Cr and Mo contents, unlike chi. ► Sigma is incoherent, contains high Mo and causes low toughness at 900 °C.