利用高精度差分膨胀仪对冷却过程中T91钢奥氏体稳定化的相变行为进行分析,研究了在Ms点以上温度保温时奥氏体稳定化现象对T91钢马氏体转变开始温度的影响。研究表明:在T91钢Ms点以上较高温度保温时,出现马氏体转变开始温度高于Ms点的明显的反稳定化现象,并随保温时间延长反稳定化程度增加;在Ms点以上较低温度保温时,T91钢的马氏体转变开始温度低于Ms点,且随保温时间的延长继续降低,而其最终组织仍为完全马氏体。
The influences of austenitic stability on the starting temperature of the martensite transformation for T91 steel were studied by using a differential dilatometer.The results show that when isothermal holding temperature was higher than the upper M_s,T91 steel possesses obvious anti-stabilization characterization.The anti-stabilization has a stronger tendency with prolonging the holding time.On the other hand,when isothermal holding temperature is just higher than M_s,the martensite start temperature of T91 steel is lower than M_s,and it decreases continuously with prolonging holding time,but final structure keeps completely martensite.