悬浮浇注对GCr15轴承钢凝固过程的影响

Effects of Suspension Casting on Solidification Process of GCr15 Steel Ingot

通过研究悬浮浇注工艺下GCr15轴承钢的凝固动力学过程来探讨悬浮剂的作用机理,并在实验的基础上分别讨论悬浮浇注工艺对钢锭凝固过程的温度分布、凝固速度、结晶温度间隔以及形核率的影响.实验结果表明,悬浮浇注能有效地提高钢锭的凝固速度,改善钢锭截面的温度分布和溶质元素的分布,减小合金的结晶温度间隔,增加钢锭形核率.其结果使钢锭凝固时间缩短,化学成分分布均匀,缩松缩孔减少,结晶组织细化.

The mechanism of inoculation in the case of suspension casting process has been studied through solidification kinetics. The effect of suspension casting process on temperature field, solidification rate, temperature gap of crystallization, effective distribu tion coefficient of solute and nucleation frequency during solidification process in steel ingot were discussed on the base of experiments. It has been found that the suspension casting process can increase both cooling rate and solidification rate of steel ingot, improve the temperature field and solute distribution, narrow the temperature gap of crystal- lication, and increase the nucleation frequency. Thus, the solidification time can be shorten, the solute can be well distributied, the shrinkage porosity can be reduced and the grain of crystallization can be fined.