【作者】 杨小容；

【导师】 陈崇峰； 倪红卫；

【作者基本信息】 武汉科技大学 ， 冶金工程， 2004， 硕士

【摘要】 柳钢热轧板产品中发现有超声波探伤不合格产品，检验发现其主要原因是钢中大颗粒夹杂物含量过高。根据柳钢生产现场的实际需要，针对柳钢热轧板的这类质量缺陷，本文对该中间包冶金过程进行了模拟研究。在1：0.6缩小比例的有机玻璃模型中，对其下渣量和平均停留时间等数据进行了测定。同时使用PHEONICS软件计算了不同条件下中间包内钢液的流动情况，以验证水力学模型实验的结果，并反过来指导水模型实验。通过物理模拟和数学模拟，得出以下结论： (1)在相同中间包结构和生产条件下，中间包浇注液面高低对下渣量有一定影响，随着液面升高中间包下渣量降低；当中间包钢水液面低于一临界高度时，则会在水口附近形成汇流旋涡，容易造成卷渣。 (2)不同结构类型的中间包的卷渣临界高度是不同的。 (3)多炉连浇中的大包换包加剧了中间包内的湍流流动，明显增加了中间包的下渣量；而且下渣量随着大包换包时中间包液面高度的降低而急剧增大。 (4)通过比较不同结构中间包的下渣量和数学模拟发现，阶梯型中间包结构较佳，尤其是在采用阶梯型结构基础上增设两堰一坝的中间包结构(试验方案8)，使得下渣量很少，但其平均停留时间比原结构稍短些。综合起来看，方案8的中间包结构有利于钢液的高质量浇注。 (5)同原中间包结构相比，采用阶梯型结构的中间包还可以获得提高金属收得率的效果。 (6)不论是开孔全高挡墙的原结构的中间包，还是阶梯型结构的中间包，其注流区内部强烈的注流和回流对中间包包壁的冲刷都比较严重，这会缩短中间包衬的寿命，同时由于耐材的熔损而增加了大颗粒非金属夹杂进入钢液的机会，因此要采取措施减弱注入流区的注流和回流。更多还原

【Abstract】 The hot rolled plates of Liuzhou Iron & Steel Corporation are unqualified for ultrasonic inspection, Checking found that it is mainly caused by a high content of large grain inclusions. To solve this problem, this paper simulated the metallurgical process of this tundish. The data, such as the quantity of the slag involved in the mould as well as the mean residence time and so on, are measured within an organic glass model with the ratio of 1 : 0. 6. At the same time PHEONICS software was used to calculate the flow field under different conditions to test the results got by the hydraulic model experiment, accordingly direct the experiment. The following results are obtained by physical and mathematical simulation.(l)The pouring height of the tundish has a certain influence on the quantity of the slag involved in the mould with the same tundish structure and production conditions. The slag quantity reduces as the liquid level rises; when the fluid level is under of a critical height the confluence vortex will appear near the nozzle, which easily entraps the slag. (2)The critical heights of entrapped slag are different for dissimilar tundishstructures.(3)The reopening of the ladle aggravates the turbulent flow in the tundish and markedly increases the quantity of the slag involved in the mould, furthermore, it varies sharply when the reopening height also lowers.(4)The trapezoidal tundish is better by comparing the results of mathematical modeling and the quantity of the slag involved in the mould of various tundish structures, especially the scheme 8 with two weirs and one dam has only a few slag quantity, but its mean residence time is a little short than original program. On the whole, the tundish structure of the scheme 8 is favored for a high-quality steel. (5)Compared with the original program, the trapezoidal tundish also can reducethe yield loss of metal at the last pouring heat of each tundish. (6) Intensive pouring flow and reflux in all types of tundishes heavily wash the tundish wall, which can generate foreign inclusion and also shorten the life of tundish, so measures have to be taken to weaken pouring flow and reflux.更多还原