Effect of RE-Al-N on structures and properties of M2 cast high speed steel

M2 cast high speed steel was inoculated by addition of rare earth(RE)-Al-N, network eutectic carbides were eliminated, matrix microstructures were refined and the segregation of tungsten and molybdenum elements was relieved. In the condition that the hardness does not decrease, impact toughness obviously increases. Quenching at 1180 degreesC and three-times tempering at 560 degreesC, the hardness of M2 cast high speed steel is 65 similar to 66 HRC, and impact toughness reaches 21. 3 J . cm(-2). Modified M2 cast high speed steel has excellent thermal fatigue resistance and high temperature wear resistance. Roller made in modified M2 cast high speed steel has excellent service effect when it is used in slit rolling mill of hot rolling bar mill.