Nb对M2高速钢共晶碳化物组织的影响

研究了铌对Ｍ２高速钢的共晶碳化物组织和共晶碳化物高温球化的影响。试验表明：在快冷条件下，随着铌含量的提高，块状碳化物增多；在慢冷条件下，少量的铌就可使Ｍ２高速钢析出形状特殊的含铌碳化物；铌不进入基体和片状的Ｍ２Ｃ型碳化物、只存在于铌碳化物中，试验还表明：加入铌后不影响片状的Ｍ２Ｃ型碳化物的高温球化。但含铌碳化物本身高温球化很困难。

Effect of Nb on the Microstructures of Eutectic Carbides in M2 High Speed Steel

The effect of Nb on the as-cast microstructures and the prespheroidization at elevated temperature of eutectic carbides of M2 high speed steel was studied. The experiments show that the block carbides increase with Nb content rise at fast cooling rate,and that when the Nb content is small the Nb carbides with particular shape would be precipitated during solidification at slow cooling rate,however, the Nb is not found in the matrix or the lamellar M2C carbides. The results also indicate that Nb has no effect on the prespheroidization of M2C plate carbides, but the prespheroidization of Nb carbide is tool diffficult.