Abstract: Through the method of queuing theory, a mathematical model of the queuing of continuous casting billets at cast-rolling interface of the billet straight rolling process is constructed, and a case analysis of the queuing theory is carried out on the billet straight rolling production line of 2 × 70 t EAF-6 strand 150 mm × 150 mm billet at a steel mill. On the premise of ensuring the direct rolling rate, the output of the production line increases by optimizing the direct rolling process, and the liquid steel quantity increases from 1.88 t/min to 2.3 t/min. In the billet direct rolling production system ,the shorter the average waiting time of continuous casting billet, the higher the efficiency of direct rolling production at the production line ； In order to maximize the output of the straight rolling process, it is necessary to satisfy the same amount of steel in the continuous casting process and the rolling process. In order to achieve the highest straight rolling efficiency, that is, the largest straight rolling rate, the average waiting time of the continuous casting slab in the queuing system needs to be less than the limit waiting time of the casting slab. Only when the above two conditions are met at the same time, the casting-rolling connection matching of the billet straight rolling process is optimal.

Key words: Direct Rolling Process, Queuing Theory, Billet Conveying Connection Optimization, Mathematical Model

摘要： 通过排队论的方法，构建了方坯直接轧制工艺铸-轧界面的连铸坯排队的数学模型,并对钢厂2 × 70 t EAF-6流150 mm × 150 mm方坯直接轧制生产线进行排队论的案例优化分析。在保证直接轧制率的情况下，钢水量由1.88 t/min提高到了 2.3 t/min,直接轧制优化工艺提高了生产线的产量。在方坯直接轧制生产系统中，连铸坯的平均等待时间越短,生产线的直接轧制率越高；当连铸工序与轧钢工序的逋钢量相同时,直接轧制工艺的产量达到最大;当排队系统中连铸坯的平均等待时间小于铸坯的极限等待时间时,直接轧制工艺的效率最髙；只有同时具备以上两个条件时，方坯直接轧制工艺的铸-轧衔接匹配达到最优。

关键词: 直接轧制工艺, 排队论, 铸坯衔接优化, 数学模型