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奥钢联林茨公司为了生产厚355 mm、宽1 600 mm的特厚板坯,升级改造了第3炼钢厂的5号连铸机。该弧形连铸机最初设计生产的板坯最大厚度为285 mm,弧形半径为10 m,配置了直结晶器,对带液芯的铸坯进行弯曲和矫直。在这种类型的连铸机上生产厚度为355 mm铸坯的主要问题是板坯的几何形状。由于弯曲时铸坯角部变形,铸坯可能出现小的皮下热裂纹。为了模拟在浇注过程中结晶器液面到弧形段开始位置的连铸板坯变形,使用ABAQUS软件开发了有限元3D模型。该热力学模型结合材料的粘弹性定律计算浇注过程凝固坯壳的张应力和压应力。据观测,模拟计算出的浇注过程凝固坯壳的张应力和压应力的分布与小热裂纹的外形大致相符。还将抽样测量的板坯几何形状与有限元计算结果进行了比较。采用热机建模计算结果,通过优化结晶器锥度和强化出结晶器后铸坯窄面的冷却,改进了板坯的几何形状。
VAI Linz upgraded the No. 5 caster from Plant No. 3 in order to produce extra-heavy slabs 355 mm thick and 1,600 mm wide. The arc caster was originally designed to produce a slab with a maximum thickness of 285 mm and an arc radius of 10 m. A straight crystallizer was equipped to bend and straighten slab with a liquid core. The main issue for producing slabs with a thickness of 355 mm on this type of caster is the slab geometry. Due to the deformation of the slab corner during bending, the slab may experience small subcutaneous hot cracks. In order to simulate the deformation of continuous casting slab from the mold surface to the beginning of the arc segment in the casting process, finite element 3D model was developed by ABAQUS software. The thermodynamic model is based on the viscoelastic law of materials to calculate the tensile stress and compressive stress of the solidified shell during pouring. According to the observation, the distribution of tensile stress and compressive stress of the solidified shell calculated by the simulation is roughly in accordance with the shape of the small hot crack. The sampled slab geometries were also compared with the finite element calculations. The heat engine modeling results are used to improve the slab geometry by optimizing the taper of the mold and strengthening the narrow face of the slab after cooling.