X12CrMoWVNbN10-1-1铁素体耐热钢中的马氏体相变过程

通过膨胀试验研究了X12CrMoWVNbN10-1-1铁素体耐热钢在不同奥氏体化条件下的马氏体相变过程.结果表明:在温度1010~1 200℃奥氏体化15 min条件下,马氏体相变的开始温度点Ms与结束温度点Mf随着奥氏体化温度的增加而升高;在1070℃奥氏体化时,Mf随奥氏体化时间的延长而升高,而在奥氏体化时间小于3 h时,随着奥氏体化时间的增加,Ms上升,在奥氏体化时间超过3 h后,Ms稳定在460℃左右;根据膨胀曲线拟合得到在1070℃奥氏体化保温不同时间条件下的马氏体相变动力学方程.

Martensitic Transformation in X12CrMoWVNbN10-1-1 Ferrite Heat-Resistant Steel

Dilatometric studies on X12CrMoWVNbN10 1 1 ferrite heat resistant steel were carried out to investigate the martensitic transformation under different austenization conditions. When the austenitizing temperature increases from 1 010 ℃ to 1 200 ℃ and the holding time keeps at 15 min, Ms and Mf increase with the increasing of austenitizing temperature. When the austenitizing temperature keeps at 1 070 ℃ and the holding time changes from 5 min to 20 h, Mf increases with the increasing of the holding time, and Ms increases with the increasing holding time only for the first 3 h, and then reaches a constant value of 460　℃　when the holding time exceeds 3 h. A new kinetic equation for martensitic transformation for this steel austenitized at 1 070 ℃ was obtained based on the dilatometric curves tested, which sets up the relationship between the volume fraction of martensite, transformation temperature and the austenization holding time.