高速钢复合轧辊液固结合过程数值模拟

Numerical Simulation of Liquid-solid Bonding Process of High Speed Steel Compound Roll

在试验的基础上，建立了高速钢复合轧辊铸造过程中外层高速钢钢液充型湍流流动及辊芯和外层高速钢液固结结合时的三维速度场和温度场的计算模型，模拟了辊芯预热温度对凝固及界面结合情况的影响。结果表明，高速钢钢液在铸型中是从下到上、从两侧的交界面向中间顺序凝固的，但随着辊芯表面预热温爱的不同，呈现出不同的特点。在同一截面上，当预热温度较低时，其最后凝固的位置位于工作层金属中间的某一位置，当预热温度较高时，最后凝固的位置随于工作层金属和辊芯之间的界面上。预热温度较低时，两者之间将难以形成冶金结合，预热温度适宜时，两者之间可以形成良好的冶金结合，适宜的辊芯预热温度为1100～1200℃。

The 3-dimensional flow and temperature field as well as turbulent flow models were established to simulate the liquid metal onflow of outer shell high speed steel during filling and liquid-solid bonding of roll core and shell metal based on the practical experimental data, observing the effects of pre-heating temperature of roll core on solidification and liquid-solid bonding. The results show that the molten high speed steel is progressively solidified from underside and two-side interfaces to upper and midst in the mold, however, the solidification characteristics are different with the preheating temperature variation of roll core. With lower pre-heating temperature, the end-solidification position lies in the middle of shell metal while it lies in the interface of shell metal and roll core with the higher preheating temperature at the same sections. The shell can tightly bond with the core to form the compound roll with proper preheating temperature, however, the metallurgical bonding can not be found with the lower preheating temperature for the core. The optimized preheating temperature of the core is about 1 100~1 200 ℃.