特厚板坯凝固过程三维热模拟研究

3D Thermal Simulation of Extra Thick Slab in Continuous Casting Process

连铸坯重压下技术是改善大断面铸坯中心偏析、缩孔,提升铸坯致密度的有效手段,但重压下位置的合理与否直接影响到重压下技术的应用效果。本文以断面420 mm×2390 mm的ES355特厚板坯为研究对象,建立了温度场三维有限元分析模型,通过现场测温和射钉实验的凝固终点测试验证了模型的可靠性;利用模型研究了过热度、拉速和比水量对ES355凝固过程温度场和固相率的影响规律。结果表明,相比过热度和二冷比水量,拉速对ES355铸坯温度场、凝固终点和固相率的影响较大。

Heavy reduction technology for continuous casting was an effective mean to reduce central segregation,shrinkage cavity and improve density of large section slab.However,the rationality of pressure position directly affected the application effect of heavy reduction technology.ES355 extra-thick slab with a section of 420 mm×2390 mm was used as the research object to establish a three-dimensional finite element analysis model of temperature field.The reliability of the model was verified by field measurement and solidification end point test of nail shooting experiment.The effects of superheat,drawing speed and specific water on temperature field and solid phase ratio in ES355 solidification process were studied by using the model.The results show that compared with superheat and secondary cooling water,drawing speed has a great influence on the temperature field,solidification end point and solid phase ratio of ES355 casting billet.