ELECTRON MICROSCOPE STUDY ON δ-EUTECTOID IN HIGH SPEED STEEL

The morphology and structure of δ-eutectoid and the transformation of δ-eutectoidicaustenite in high speed steel have been studied under SEM and TEM.The δ-eutectoid inas-cast high speed steel is rod-shaped eutectoidic units with different orientations and ismarkedly surrounded by carbide shell.The eutectoidic carbide is rod-shaped M_6C of squareeross section.The eutectoidic austenite may transform into pearlite structure during cooling.