稀土对高碳高速钢组织和性能的影响

Influence of Rare Earth on Structure and Properties of High Carbon High Speed Steel

在成分为Fe-5%V-5%W-5%Mo-5%Cr-3%Nb-2%Co-2%C的高碳高速钢中添加稀土,研究了稀土对高碳高速钢铸态组织、热处理组织和力学性能的影响。结果显示:稀土处理使高碳高速钢的奥氏体晶粒和共晶组织明显细化,共晶组织中片层状碳化物变短、变细。热处理后,共晶碳化物大部分变成团球状且分布均匀。稀土处理高碳高速钢的硬度和红硬性略有增加,冲击韧性提高37.81%,达到10.17 J/cm2,分析了稀土在高碳高速钢中的作用机理及改善合金性能的机制。

Some rare earth （RE） is added to high carbon high speed steel whose compositions are as follows： Fe-5% V-5% W-5% Mo- 5% Cr-3% Nb-2% Co-2% C. The effects of RE on the as-cast microstructure, heat treatment microstructure and mechanical properties of high carbon high speed steel have been investigated. Results show that, when suitable RE is added into high carbon high speed steel, the austenite and eutectic carbides have been changed. The austenite grains and coarse eutectic structure are refined, and flake car- bides in eutectic structure become short and thinner. After heat treatment, most of eutectic carbides are spheroidized and distributed uniformly. The hardness and hot hardness of modified high carbon high speed steel are slightly increased, impact toughness is greatly increased by 37.81% and reaches 10. 17J/cm^2. The mechanism that RE improves the structure and properties of high carbon high speed steel is analyzed.