上引连铸条件下铸坯力学行为的研究

利用作者设计的测力传感器测试了上引连铸过程中铸坯所受到的牵引力。结合铸坯凝固过程温度场的研究，分析了铸型／结晶器界面上的摩擦力作用规律，提出了摩擦力的分布方式，并依据实验结果确定了摩擦力的最大值及其作用位置。根据高温状态下铸坯合金的流变力学行为，对摩擦力与铸坯表面质量的关系进行理论分析，推导出铸坯表面环纹尺寸的计算公式。根据Ｇｒｉｆｆｉｔｈ能量判据，分析了上引连铸条件下铸坯表面环纹发展成为裂纹的力学与几何条件及连铸工艺参数的影响。

MECHANICAL BEHAVIOR OF THE STRANDS IN UPWARD CONTINUOUS CASTING

A force transducer was designed to measure the pulling force by which the strands were withdrawnduring upcasting. With the results of ternperature field in the strands, the friction between the strands andthe mold was analysed. The distribution of the friction was proposed and the maximum friction and its ac-tion position were determined according to experimental results. Based on the rheologic characteristics ofthe strand alloy at elevated temperature, effects of the friction on the surface quality of the strands werestudied. A formula used to calculate the sizes of ring marks in the strand surface was deduced. According tothe Griffith's energy criterion, mechanical and geornetric conditions under which the surface ring markswould develop to cracks and effects of the casting technological parameters on the conditions were dis-cussed.