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.
Die Kenntnisse der Erstarrung des flüssigen Stahls zu festem Stahl sind wichtig für die Stranggießtechnologie. Die mathematische Simulation ist ein wertvolles Instrument, diese Aufgaben zu bewältigen. Die Erstarrung vom Meniskus bis zur Durcherstarrung wird simuliert. Die Information, die mit Simulation erhalten wird, dient als wichtige Basis für die Optimierung der Stranggießtechnik.
The thermal behaviour of the continuous casting mould has a critical influence on strand surface quality, casting productivity and operating safety. voestalpine Stahl GmbH has long been interested in the field of research into mould behaviour, and began with the investigation of heat flux in 1995, and then of thermal variability in 1999. Since 2000, an online mould thermal monitoring system for heat flux density, thermal variability and friction has been installed. The heat flow density in the mould is determined by measuring the inflow and outflow temperatures and the throughflow volume of the primary cooling water. Temperature as measured by a thermocouple based breakout detection system in the mould copper plate is used to investigate the thermal variability. These online measured values have been employed to examine the influence of casting parameters, steel analysis and casting powder on the heat flux and thermal variability, and the relationship between these variables and cracking. The knowledge gained through these wide ranging plant based investigations has been used as a major tool in the diagnosis of problems ( such as breakout and sticking), for optimisation of the process, particularly in the field of casting powders, and for control of slab quality. In particular, this knowledge has been incorporated into online mould thermal monitoring.
