不同钢包底吹氩模式对钢液精炼效果的影响

Effect of Different Argon Blowing Modes on Refining Effect of Molten Steel

以180 t双孔底吹氩钢包为研究对象,对6种钢包底吹氩模式进行数值模拟,并结合现场试验与当前采用的吹氩模式进行对比。研究发现:(1)钢液的混匀时间随吹氩量的增加而减少,吹氩量一定时,差流量吹氩模式对钢液的搅拌强于等流量吹氩模式。(2)不同的钢包底吹氩模式,渣眼形成的位置不同,渣眼面积也不同。总流量一定时,差流量吹氩模式钢液面最大流速大于等流量吹氩模式,易发生钢液卷渣。(3)差流量吹氩模式渣线处渣层厚度的波动大于等流量吹氩模式,且流量差值越大,波动越剧烈。(4)差流量吹氩模式通过“强-弱”流股的配合,进一步强化了钢包底吹氩的钢液精炼效果。工业试验表明,采取等流量吹氩模式(500 L/min—500 L/min),钢中的较大夹杂物的数目明显多于差流量吹氩模式(400 L/min—600 L/min)。

In this paper, one 180 t double-hole bottom argon blowing ladle is taken as the research object. Based on the specific production conditions, six modes of argon bottom blowing in ladle are numerically simulated, and combined with the field test, it is compared with the argon blowing mode currently adopted. The results show that:(1) The mixing time of molten steel decreases with the increase of argon blowing amount. When argon blowing amount is constant, the argon blowing mode with differential flow rate is stronger than that with constant flow rate.(2) Different modes of argon blowing at the bottom of ladle have different locations and areas of slag holes. When the total flow rate is constant, the maximum velocity of molten steel surface in the differential flow argon blowing mode is greater than that in the constant flow argon blowing mode, which is easy to cause slag entrapment.(3) The fluctuation of slag layer thickness at the slag line in differential flow argon blowing mode is greater than that in constant flow argon blowing mode, and the greater the flow difference, the more severe the fluctuation.(4) The differential flow argon blowing mode further strengthens the refining effect of molten steel by argon blowing at the bottom of ladle through the cooperation of "strong-weak" streams. And the industrial test shows that the number of larger inclusions in steel is obviously more than that in argon blowing mode(400 L/min—600 L/min) with constant flow rate(500 L/min—-500 L/min).