【作者】 何维祥；

【导师】 唐萍； 陈文满；

【作者基本信息】 重庆大学 ， 冶金工程， 2007， 硕士

【摘要】 钢包在炼钢工序的生产过程中是不可缺少的设备,其使用寿命的长短,保温性能的好坏,直接影响到炼钢工艺的顺行,产品的质量及产量。2006年,重钢由于新1350m3高炉投入生产,迫使炼钢厂产钢量达到330万吨规模。在生产场地狭小,钢包数量不能增加的情况下,需要完成如此规模的产量十分困难。根据测算,要完成330万吨/年的生产规模,必须提高转炉出钢量达到80±2吨。经计算,当永久层减薄30毫米,在保证钢包的自由空间为600毫米条件下,能够满足出钢量达到80±2吨的要求。同时进一步的提高钢包包龄,加快钢包周转,对完成330万吨/年的生产规模也是必须的。由于减薄永久层,钢包的保温性能势必降低,该课题针对重钢330万吨/年的生产规模的要求,开展了在减薄钢包永久层厚度条件下、提高钢包耐材寿命,实现薄钢包的高效保温性能研究工作。该课题通过研究钢包砌筑方式、钢包砖材质、精炼工艺及精炼渣系,首先实现了减薄钢包的长寿命要求,钢包包龄由以前的65～70次提高到了120次以上,比重钢传统钢包包龄提高了约80%。经过滑板机构的改造,钢包准备时间降低了5～6分钟,钢包周转速度加快,钢包在线准备时间由以前的12分钟以上缩短到10分钟以下,保证了330万吨/年的生产规模的实现。通过钢包传热分析模拟计算,提出钢包的热损失主要是通过包壁,而影响包壁热损失的主要因素是绝热层的材质和厚度,钢包工作层、永久层导热系数偏高,材质性能对热损失的影响不如绝热层大。覆盖剂对降低渣层的热损失有着重要作用,但其比例仅为钢包总热损失的4.41%。通过对不同类型钢包绝热层、永久层保温性能、耐压强度,以及覆盖剂保温性能实验室及生产现场应用实验研究,得出了采用20mm河北硬质纤维板+90mm3#混合永久层+ 1#复合颗粒覆盖剂,不仅达到了减薄前钢水转运过程中的温降特征,而且保温效果还优于原厚壁钢包,钢水在出钢及Ar站或LF炉出站温度现行制度上降低了5℃。对钢包烘烤过程温度的变化进行研究,得出了不同种类钢包,包括换永久层的全修钢包,不换永久层的全修钢包,换渣线的挖修钢包的烘烤制度,保证了钢水转运过程中,温度变化的稳定性。综合上述研究结果的应用,连铸中间包钢水温度合格率上升到了87%以上。更多还原

【Abstract】 Ladle is indispensable during the process of steelmaking, and whose life-span and thermal insulation property have an important influence on steelmaking process and product quality.In 2006, the new blast furnace 1350m3 of ChongSteel was put into use, which results in the yield of steel increasing up to 3.30 million tons per year. Under the condition that the production place and amount of ladles are limited, it is difficult to come true. Based on investigation, in order to realize the scale, the yield of oxygen convertor must attain about 80 tons. When permanent layer decreases 30mm, there is a 600mm free space in ladle, and the aim of 80 tons production can come true. At the same time, in order to accomplish the production scale of 3.30 million tons per year, it is necessary to improve the life-span and the turnover rate of ladle further .Because the thickness of permanent layer reduces, the thermal insulation property may decrease. Therefore, aiming at the requirement of the production scale of 3.30 million tons, focus of this study is how to implement high efficient and improve thermal insulation property of ladle when whose thickness of permanent layer is reduced.By studying on the construction way and material of brick of ladle, refining technique and slag system, the requirement of prolonging the life of the ladle with thin layer was realized firstly. The life-span of ladle has increased from 65～70 times to more than 120 times, which has enhanced about 80% than traditional ladle of ChongSteel. Through improving slide mechanism, the prepared time of ladle has decreased 5～6minutes, the turnover rate of ladle increased, and the prepared time on line from more than 12 minutes to less than 10 minutes. Thus the production scale of 330 million tons per year is realized.Through thermal analysis and simulation calculation of ladle, the idea that the heat is reduced via ladle wall is proposed. Whereas the material and thickness of insulating layer are the main factors affecting heat-loss. Because the conduction coefficient of work layer and permanent layer are high, material property has less influence on heat-loss than thermal insulating layer. The covering agent plays an important role in decreasing heat-loss of slag layer, but the ratio is only 4.41% of total heat-loss of ladle.By investigating the thermal insulation property of insulation layer and permanent layer, compressive strength, the thermal insulation property of covering agent and industrial trials, the system of 20mm HeBei hard fibreboard and 90mm 3# mixed permanent layer and 1# complex grain covering agent was adopted, which has not only alleviated temperature reduction in molten steel transport before becoming thin, but also thermal insulating effect been better than original ladle with thick wall, and the temperature at tapping, Ar station or out-ladle furnace decreased 5℃.By investigating the variation of temperature of baking process of ladle, the better system of the completely repaired ladle with changing permanent layer, completely repaired ladle without changing permanent layer and the dig repair ladle was obtained to ensure the temperature stability of molten steel in transport. Based on the application of research results above, the qualified rate of temperature of tundish has increased more than 87%.更多还原