ThedevelopmentofhighstrengthhotrolledTRIP(Transformationinducedplasticity)-aidedsteelsheetswith780MPawascarriedoutbytakingintoaccounttheadditionofNbandMoto0.2C–1.5Si–1.5Mnmass%steelandcoilingconditionsafterhotrolling.Theresultsrevealthattheadditionof0.05%NbcanattainhigherelongationwithhigherstrengthcomparedwithNb-freesteel.Theobtainedtensilestrengthinthissteelwashigherthan780MPa.Themultipleadditionof0.2%Mowith0.05%NbresultsinhigherTS(TensileStrength)bythelargeamountoffineNbMoCprecipitatesthanNbcontainingsteelwithoutthedeteriorationofTS–El(Elongation)balanceunderthepossiblehotrollingconditions.Thegoodductilityin0.05%Nbcontainingsteelwasmainlyobtainedbylargevolumefractionandhighcarbonconcentrationofretainedaustenite.Inaddition,finelydispersedretainedaustenitemadesomecontributiontotheimprovementofductility.