The reduction of area and tensile strength of Φ10 mm×120 mm specimen drilled and turned from 280 mm ×380 mm cast billet of0.03Nb
0.03Nb-0.02Vand 0.05VMicroalloyed 0.75~0.78C high carbon steel have been tested at 1300~800 ℃ by Cleeble 1500D thermal simulation machine.Results showed that the hot plasticity of V-steel in first brittle zone ≥1200'℃ and third brittle zone1000~800 ℃ was better than that of Nb-steel and Nb-V steel.It was indica- ted by scanning electron microscopy and energy spectrum analysis that Fe-Nb-C eutectic existed in cast billet of Nb- steel
and Fe-Nb eutectic existed in cast billet of Nb-V steel added V.