EH40钢中第二相粒子对奥氏体尺寸的影响

Effect of second phase particles on austenite grain size in EH40 steel

分析了EH40级船板钢在不同奥氏体化温度(900~1300℃)和奥氏体化时间(0~150 min)下,第二相粒子对奥氏体尺寸的影响。结果表明:在相同奥氏体化温度下,随着奥氏体化时间的增加,奥氏体尺寸增加缓慢;在相同奥氏体化时间下,随着奥氏体化温度的提高,奥氏体尺寸增加迅速;当奥氏体化温度介于1050~1100℃等温0.5~150 min,奥氏体尺寸增加最快,由于达到了Nb C的全固溶温度(1058℃),Nb C对奥氏体的钉扎作用消失,所以奥氏体尺寸呈指数关系上升(150~300μm)。

The impact of precipitation of second phase particles on austenite grain size evolution of EH40 ship building steel at different isothermal heating temperatures(900-1300℃)and isothermal holding time(0-150 min)was analyzed.The results show that at the same temperature,austenite grain size increases slowly with the increase of isothermal heating time;at the same isothermal holding time,austenite grain size increases rapidly with the increase of temperature.When the isothermal heating temperature is between 1050-1100℃and the isothermal holding temperature is 0.5-150 min,the austenite grain size increases fastest.Due to the full solution of Nb C(1058℃),the Nb C pinning effect on austenite grain growth disappears.The austenite grain size increases exponentially(150-300μm).