The method of integrated scheduling for steelmaking and hot rolling shop based on hot chain logistics

Steelmaking, continuous casting and hot rolling are not only the key processes of steel production, but also the processes costing lots of energy. Pig iron is made into slabs by the process of steel making and continuous casting. The hot rolling process makes slabs into hot coil. A slab yard is built between the two parts as a buffer area to coordinate the production rhythm. In this work flow, if the slab can´t be transferred to hot rolling process timely when it´s cast to a slab with high temperature, it will stay in the slab yard and auto-cool to room temperature. When it is called for hot rolling, the slab needs to be reheated from room temperature to about 1250°C. It can be seen that lots of energy loss exists in the process of reheating slabs. This paper proposes a method based on heuristic and mathematical programming to solve this problem, as so-called, the integrated scheduling problem. Validation research is taken for the models and algorithm. The experiment result shows that this solution can solve the problem correctly and achieve a short solve time even for large scale problem.