【作者】 李宏亮；

【导师】 陈登福；

【作者基本信息】 重庆大学 ， 冶金工程， 2006， 硕士

【摘要】 连铸坯二次冷却在连铸生产中占有非常重要的地位,不但关系到铸坯的质量,而且还与铸机产量密切相关。优化控制二次冷却越来越重要,而计算机数值计算和仿真技术的快速发展为二次冷却制度的制定和优化提供了便利的技术条件。通过建立连铸坯凝固传热模型、确定准确的各计算参数、编写计算程序对影响连铸坯凝固过程的各个阶段和各种工艺因素进行数值模拟,迅速、准确地找出影响连铸坯凝固过程的规律和工艺控制措施,可以提高连铸机生产能力,改善、控制铸坯内部组织结构与质量,取得更好的经济和社会效益。济南钢铁股份有限公司第一炼钢厂一号方坯连铸机是1989年由德马克设计建成投产的,近来,设备年久以及当初设计的连铸工艺无法满足当今高效连铸技术的发展要求,在质量、产量和生产率方面均存在较大的不足。2005年由重庆大学和济南钢铁公司联合对铸机进行了二次冷却改造,建立了适应该铸机具体结构特点的方坯凝固传热数学模型,对二次冷却制度进行了优化并在此基建上开发了用加权平均速度替换瞬时速度从静态水表调用二次冷却水量进行冷却的方坯动态模型。在拉速突然变化时,方坯动态模型能对防止短时间内二次冷却强度过大或不足起积极作用。在连铸生产过程中,改善连铸坯的凝固冷却、制定合理的二冷制度,钢种的高温物理性能和高温力学性能均十分重要。课题对广西柳州钢铁公司连铸板坯Q345和AH36两个典型钢种部分高温物理性能及高温力学性能进行了测试。测试结果为确定连铸目标表面温度曲线和其它相关参数进而为开发板坯二冷动态模型提供了重要的基础数据和依据。为了在不同的浇注条件下对二次冷却进行良好的监测和控制以获得理想的铸坯表面温度分布,建立铸坯凝固传热数学模型仿真计算铸坯温度场分布,并根据铸坯表面温度对二冷冷却喷水量进行在线计算,以便通过控制系统使铸坯表面温度保持沿预先设定的目标表面温度变化,更好地控制铸坯质量。课题根据柳钢板坯连铸机的特点,建立了板坯连铸一维传热模型,根据表面温度计算结果和目标温度差值采用比例、积分、微分算法调整水量。连铸板坯二次冷却动态模型选用Microsoft的VisualBasic6.0高级语言,编程实现对连铸坯各节片的动态跟踪,实时计算各节点的温度、坯壳厚度和二冷喷淋段的冷却水量,以及实现了各结果的动态显示,模型界面设计友好。更多还原

【Abstract】 The control of secondary cooling holds very important status during continuous casting. The control of secondary cooling water spraying not only relates to the product quality directly, but also affects caster machine output closely. Perfecting secondary cooling system through optimizing is more and more important, numerical analysis and technique of simulation by computer has provided the convenient engineering facility. Constructing heat transfer of mathematic model, determining accurate computation parameter and compiling computational procedure to analog simulate the cast process, rapidly, accurately discover rule and casting craft in the solidification process of continuous casting blank that can obtain better economy and social efficiency.NO.1 billet continuous caster in the first steelmaking plant of Jinan Iron and Steel Co. Ltd. was designed by DeMark and putted into production in 1989. Recently, because the year equipment inline is long and the continuous casting craft designed firstly can’t satisfied the high efficient continuous casting that have high requirement on quality, production rate and casting speed.In 2005, modification works to No.1 continuous cater secondary cooling system was carried by the joint of Chongqing University and the Jinan iron and steel company. Heat transfer mathematic model of billet is built corresponding with casting machine structure of No.1 caster. Dynamic billet secondary cooling system is developed with weighted average velocity replacing actual speed to call secondary water cooling casting blank from static water list. Dynamic billet secondary cooling system can resolve excessively cooling intensity or deficiency in the secondary zone when the casting speed changes abruptly.Research on mechanical behavior and physical property of steel casting blank under high temperature in order to ameliorate continuous casting blank solidifying process and formulate reasonable secondary cooling systems is significant. Paper select steel Q345 AH36 casting in Liuzhou Iron and Steel Company to test part of high temperature property of steel casting blank. The test result provides basic data for determining surface temperature curve of slab cooling and other calculation parameter for developing slab dynamic model.In order to monitor and control secondary cooling in a good way under vary casting condition, calculate the amount of secondary cooling water in-line according to更多还原