稀土对14MnNb钢的微合金化作用

Effects of Rare Earth on Microalloying of 14MnNb Steel

１４ＭｎＮｂ钢在轧制态下，随着固溶稀土增加，碳化铌析出增加，颗粒变小且弥散分布，珠光体星球状、数量减少。当固溶稀土含量为１７４×１０（－６）时，板条状贝氏体变为粒状贝氏体组织。在奥氏体区，稀土使碳化铌析出的孕育期延长，有抑制碳化铌析出的作用。固溶稀土推迟了再结晶的动力学过程，并使马氏体组织变细。

For 14MnNb steel of rolling state, with increasing the amount of rare earth in solid solution, the amount of NbC precipitation increase, the particles become smaller and uniform distribution. When the content of the rare earth in solid solution is 174×10-6, these plated bainite microstructures turn to the particle ones. For austenite region, rare earth delay the start precipitation time of NbC, and reduce the effect of NbC precipitation. Rare earth in solid solution also delay the dynamics of recrystallization, and fine the martensite structure.