连铸板坯凝固过程的应变分析

通过建立连铸板坯凝固过程的传热模型和采用实测温度数据进行检验,获得了铸坯温度及坯壳厚度的数据.在此基础上建立了凝固过程的应变分析模型,得到了实际工况条件下坯壳所受的拉应变.结果表明,在正常工况下,连铸坯凝固前沿所受的应变很小,铸坯不会产生内部裂纹;当导辊开口度的偏差大于2mm时,其引起的应变大于鼓肚应变,且凝固前沿所受的应变大于临界应变,内部裂纹发生的可能性很大.支撑辊对中精度是产生内部裂纹的重要影响因素.

Strain in Solidifying shell of Continuous Cast Slabs

The surface temperature and shell thickness of continuous casts slab were obtained by modeling heat transfer during solidification process. A mathematical model of strain at solid/liquid interface was set up. The strain in the solidifying shell under normal and abnormal operation conditions was gained. The results indicate that strain is small under normal operation conditions and internal cracks never happen. But when the variation of roll gap is above 2mm, the strain caused is greater than caused by bulging. The total strain exceeds the critical one and internal cracks will appear It is of great importance to maintain the fine state of continuous casting machine to avoid the ap- pearance of internal cracks.