摘要
角部表面纵裂和偏离角裂纹是小方坯连铸中的常见缺陷。通过建立小方坯连铸结晶器内铸坯与铜管热-力耦合有限元模型,研究了不同拉速条件下小方坯在结晶器内的热-力学行为。计算分析了拉速、钢水过热度和结晶器锥度等工艺因素对结晶器内坯壳温度分布和塑性应变的影响。结果表明,铸坯角部纵裂和偏离角裂纹容易在结晶器下部发生;提高拉速、降低钢水过热度、采用多锥度结晶器均有利于降低亚包晶钢坯壳凝固前沿偏离角区域的拉应变及其裂纹倾向。一定条件下,高拉速有利于改善结晶器区域坯壳厚度和温度的均匀性、降低亚包晶钢小方坯连铸结晶器内常见裂纹的发生倾向。
Surface longitudinal cracks at the corner region are frequently observed defects during billet casting. The thermomechanical model was developed to analyze billet thermodynamics behaviors in the moldunder various casting speed.The influence of billet shell temperature distribution and plastic strain due to process factors,for instance,casting speed,superheat and taper of mold was analyzed with the model.The calculating results indicated that corner longitudinal cracks and off-corner cracks more easily originate atthe lower area in the mold. Increasing casting speed,lowering superheat and using multi-taper moldwill decrease tension strain and crack initiation tendency at solidification front.Under given conditions,increasing casting speed can improve the uniformity of shell thickness and temperature distribution of subperitectic steel billet around the corner,which is beneficial to the control of the related crack defects.
作者
邱东升
吴国庆
李亮
兰鹏
陈卫强
张家泉
QIU Dong-sheng1, WU Guo-qing2, LI Liang1, LAN Peng1, CHEN Wei-qiang2, ZHANG Jia-quan1(1. School of Metallurgical and Ecological Engineering University of Science and Technology Beijing, Beijing 100083, China; 2. Capital Engineering and Research Incorporation Ltd, Beijing 100176, Chin)
出处
《连铸》
2018年第1期13-21,共9页
Continuous Casting
关键词
小方坯
高拉速连铸
结晶器
热力耦合分析
billet casting
high-speed casting
mold
thermomechanical analysis
