材料期刊网

本文以铌质量百分数为0.17%的低碳钢为 研究对象，通过热模拟试验分析变形对高铌低碳钢奥氏体→铁素体等温相变动力学的影响，并得到了未变形、875℃变形20％和30％奥氏体向铁素体700℃等温转变的动力学曲线，讨论了热变形和铌对奥氏体→铁素体等温相变的影响机制。研究结果表明变形主要通过缩短相变孕育期来加速奥氏体→铁素体等温相变；高铌钢奥氏体→铁素体等温转变是两阶段机制，即相变初期铁素体转变率低，第二阶段相变速率高，剩余的奥氏体很快转变为铁素体。 关键词：高铌低碳钢；热变形；奥氏体→铁素体等温相变

Using thermal simulation tester,austenite to ferrite isothermal transformation for a low carbon high niobium steel with and without hot deformation was investigated．It was obtained that curves of austenite to ferrite isothermal transformation at 700℃ for the tested steel in un-deformation, deformation 20% and 30% at 875℃,respectively. Influence of hot deformation and niobium on was discussed. The results show that the ferrite transformation is accelerated by hot deformation，because incubation period of the transformation is shortened by hot deformation，and the kinetics of austenite to ferrite isothermal transformation for high niobium steel is two stage that is ferrite transformation rate is lower in the first period and is higher in the second.