【作者】 曹雄；

【导师】 张胤；

【作者基本信息】 内蒙古科技大学 ， 钢铁冶金， 2009， 硕士

【摘要】 中间包冶金是连铸工艺过程中的重要环节,在中间包内设置控流装置以改善钢液的流态有利于均匀钢液的成分、温度,促使非金属夹杂物上浮从而提高中间包的冶金效果。国内某钢厂中间包原工况(方案t00)死区体积比例大,活塞区体积比例小,夹杂物上浮临界直径大,不利于夹杂物的充分上浮。为此,基于相似原理,本文按实物与模型3:1的比例建立中间包水力学模型,采取正交试验[0]方法确立试验方案,测定了各个方案下的RTD曲线,得出其死区体积比例、活塞区体积比例两个指标值,将这两个指标和两者按综合评分法分析的较优生产条件综合平衡,找出兼顾每个指标都尽可能好的生产条件,最终确定出各因素水平的最优搭配组合方案,并对其进行结果验证。通过对中间包结构优化的物理模拟及数学模拟研究,结果表明:最佳优化方案t17各项控流装置参数,坝高为135mm、堰深为90mm、坝堰间距为155mm和堰与长水口间距为195mm。该方案平均停留时间达到了341.39s,死区体积比例降低到了16.12%,活塞区体积比例提高到了17.13%,综合评分值达到91.01,夹杂物的去除临界直径为74.82μm,均比其它方案的指标值有了明显的改观。同时对中间包底吹气做了探索研究,结果表明:最佳优化方案t37各项控流装置参数,吹气量为450L/h、堰深为110mm、气盒与堰间距为235mm和堰与长水口间距为195mm。底吹气探究优化试验最佳优化方案t37平均停留时间达到了360.32s,死区体积比例降低到了11.47%,活塞区体积比例提高到了21.95%,综合评分达到100.48。比较中间包结构优化与底吹气各方案指标值,结果表明:中间包底吹气更能充分发挥中间包的冶金效果。更多还原

【Abstract】 Metallurgy in tundish is an important step in the continuous casting process. Flow control devices in the tundish could be beneficial to equalize component and temperature of the molten steel and improve the flow state and to urge the inclusion removal through floatation and adherence.The original condition(Programme t00) is bad for the removal inclusions ,which has larger volume fraction of dead zone, smaller volume fraction of piston zone and larger critical removal diameter. So the ratio of 3:1 between the prototype and model of the tundish water model is established according to the similar principle, and optimization experiment is carried out. The programme is determined through the orthogonal test. According to assaying the RTD curves, two index values are gotten, which are the volume fraction of dead zone and volume fraction of piston zone of each programmes. The optimum condition is found in the presence of these two index value and comprehensive score system. And the result of the optimum condition is validated.According to the physical simulation and numerical simulation study on optimization of the structure, the following conclusions show: the optimum condition is height of weir 135 mm , depth of dam 90 mm , ditance between weir and dam 155 mm and distance between dam and long nozzle 195 mm . The average resident time is 341.39s, the volume fraction of dead zone decreased to 16.12%, the volume fraction of piston zone increased to 17.13%, the comprehensive score increased to 91.01 and and the critical removal diameter of inclusions is 74.8μm of this condition, which are improved.At the same time according to the study of exploring the bottom gas blowing of tundish, the following conclusions show: the optimum condition is flux of gas 450L/h, depth of dam 110 mm , ditance between weir and dam 235 mm and distance between dam and long nozzle 195 mm . The average resident time is 360.32s, the volume fraction of dead zone decreased to 11.47%, the volume fraction of piston zone increased to 21.95%, the comprehensive score increased to 100.48.Compared each index values between the optimization of the structure and the bottom gas blowing of tundish, the following conclusions show: the metallurgy effect of the bottom gas blowing of tundish is better than that of the optimization of the structure.更多还原