超宽板坯包晶钢连铸初生坯壳应力的数值模拟

Numerical simulation of stress field in a wide slab mould of peritectic steel continuous casting

利用商业软件计算了超宽包晶钢连铸过程中初生坯壳所受应力.研究结果表明,由于包晶反应引起的体积收缩,包晶成分钢种的凝固坯壳表面应力显著大于非包晶钢成分钢种,在距铸坯中心约200～400 mm处应力出现极大值;随板坯宽度的增加,坯壳表面应力增大,应力极值点向坯壳中心方向移动;连铸工艺参数直接影响包晶钢表面应力大小,随过热度减小,拉速增加,结晶器冷却强度减弱,坯壳表面应力减小,铸坯表面裂纹发生概率降低.在本研究条件下,对断面为3 200 mm×150 mm的铸坯,适宜的过热度为15～25℃,拉速为1.2 m/min,结晶器宽面冷却强度为5 500 L/min.

A numerical simulation of the thermal stress field of the solidified shell in the mold during continuous casting of peritectic steel slab was calculated with commercial software.The results showed that the thermal stress on the wide surface of the solidified shell was larger for peritectic steel slab than that for non-peritectic steel,and the maximal stress was located at 200~400 mm away from the central line.With increment of slab width,the thermal stress increased and the maximal stress moved towards the central line.In addition,the stress was also influenced by operating parameters,and it decreased with decrease of superheat degree,increment of drawing speed and decrease of cooling intensity in the mold.For the slab with section size of 3 200 mm×150 mm,the proper casting speed was around 1.2 m/min,with cooling intensity of 5 500 L/min while the superheat degree was 15 ℃ to 25 ℃ in order to prevent longitudinal crack occurring during peritectic steel continuous casting in present study conditions.