Simulation Study On Motion Behavior Of Inclusions In CC Tundish

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.