脉冲磁场对钛处理低碳钢凝固组织的影响

Effects of Pulsed Magnetic Field on Solidified Structure of Ti-bearing Low Carbon Steel

采用自行研制的脉冲磁场发生装置对含Ti低碳钢的凝固过程进行控制,利用金相显微镜、扫描电镜和能谱仪研究不同放电电压条件下的脉冲磁场对钢中夹杂物的析出行为及凝固组织的影响规律,分析不同凝固冷却速度对脉冲磁场细晶化效果的影响。结果表明:随着放电电压的升高,夹杂物的尺寸先减小后增大,晶内铁素体的数量逐渐增多,凝固组织变得更细小;降低凝固冷却速度,可延长脉冲磁场对钢液凝固过程的作用时间,晶粒的细化效果更明显;当放电电压为80 V,凝固冷却速度为60℃/min时,凝固组织几乎全部由细小的相互交错的针状铁素体组成。

The solidification process of Ti-bearing low carbon steel was controlled by self-developed pulsed magnetic field generator. With the help of metallographic microscope,scanning electron microscope and energy spectrum,the influence rules of the precipitation behavior of inclusions and solidification structure under different discharge voltages were studied. The refining effect with pulsed magnetic field under different solidification cooling rates was analyzed. The results showed that the inclusion size increases at first,then decreases with the increase of discharge voltages,while the number of intragranular ferrite gradually increases,and the grain size becomes smaller and more homogeneous. As the solidification cooling rate decreases,the action time of pulsed magnetic field on the solidification process of liquid steel is extended and the grain refinement effect is more obvious. When the discharge voltages is 80 V and the solidification cooling rate is 60 ℃ / min,the solidification microstructure is almost entirely comprised of fine and interlaced acicular ferrite.