Pulse Current High Boron-carbon Alloy Cast Organizational Impact

Treated the high-boron middle-carbon alloy for pulse current for different time and different parameters, to study the best temperature and the best time of pulse current applied, and to research the effect of pulse current parameters on the solidification micro structure of high-boron middle-carbon alloy. What’s more, the author do a simple analysis for the influence mechanism of pulse currentTreated the high-boron middle-carbon alloy for pulse current in its area of the liquid phase, the solid and liquid phase and the solid phase, found that when treated the high-boron middle-carbon alloy in its area of the solid and liquid phase, the high-boron middle-carbon alloy has the best solidification micro structure. Treated the high-boron middle-carbon alloy for pulse current at different temperature in its area of the solid and liquid phase, found that when treated the high-boron middle-carbon alloy at1175℃, the high-boron middle-carbon alloy has the best solidification micro structure. At1175℃, treated the high-boron middle-carbon alloy for pulse current for different time, found that when treated the high-boron middle-carbon alloy for3min, the high-boron middle-carbon alloy has the best solidification micro structure.The author use the single variable method to study the influence of pulse current parameters to the high-boron middle-carbon alloy. The results show that, along with the increase of pulse current intensity, the crystal ledeburite of the high-boron middle-carbon alloy reduced, the boron carbide hard phase of high-boron middle-carbon alloy broken network phenomenon more and more obvious. Hardness and impact toughness of high-boron middle-carbon alloy increased. Along with the increase of pulse current frequency, the crystal ledeburite of the high-boron middle-carbon alloy reduced, the boron carbide hard phase of high-boron middle-carbon alloy broken network phenomenon more and more obvious. Hardness and impact toughness of high-boron middle-carbon alloy increased. When the pulse width less than30μs, hardness and impact toughness of high-boron middle-carbon alloy improved as the frequency increases. When the pulse width more than30μs, hardness and impact toughness of high-boron middle-carbon alloy reduced as the frequency increases.According to the analysis, the influence of pulse current parameters to the high-boron middle-carbon alloy is the result of the Joule heating, the electromagnetic force, the electromigration effect and the Peltier heating effect. The Joule heating effect and electromagnetic force effect is most remarkable. The joule heating and the electromagnetic force effect of pulse current work together to make the eutectic ledeburite reduce, and make the hard phase broken network. Besides, the reduce of eutectic ledeburite may be associat with the electromigration effect of pulse current, and the roundness of hard phase may be associat with Peltier heating effect of pulse current.