Effect of RE-Ti Compound Modification on Microstructure and Properties of High Vanadium High Speed Steel

The effects of RE-Ti on the as-cast microstructure,heat treatment microstructure and mechanical properties of high vanadium high speed steel have been investigated.Results show that when suitable modifier is added to high vanadium high speed steel,the austenite and eutectic carbides are changed.The austenite grains and coarse eutectic structure are refined,and flake carbides in eutectic structure become short and thinner.After heat treatment,most of eutectic carbides are spheroidized and distributed uniformly.The alloying elements in the modifier can form uncontinuous hard carbide within the crystal grains or along their boundary.Thus they can refine the microstructure and improve the hardness of the high vanadium high speed steel.The mechanism that modifier improves the structure and properties of high vanadium high speed steel is analyzed.