Direct rolling of continuous casting billet for direct rolling includes three situations: one is that there is a conventional heating furnace and induction heating furnace at the same time; the other is that there is no conventional heating furnace, and the continuous casting billet is only warmed by induction heating; Instead of taking any heating measures, the temperature of the continuous casting slab itself is directly fed into the rolling mill for rolling. The direct rolling technology is suitable for the case where the rolling mill is placed on a floor of +0.00 m, because if the rolling mill is placed on an elevated platform, the billet lifting will be delayed for a longer period of time and the temperature drop is greater. For the newly-built short-process production line, the continuous casting center line and the rolling center line should be arranged on the same line. If a heating furnace is installed, the continuous casting blank can pass directly through the heating furnace, and the heating furnace is of the blank type. Steel; however, for retrofit projects, it may be necessary to traverse the gantry and add a set of roller paths to the furnace to bypass the furnace. The surface temperature of the continuous casting slab is about 800 ° C, and the temperature of the slab is raised to 1050 ° C by induction heating. The advantage of this arrangement is that when the continuous casting and rolling capacity are not matched, the excess cold billet is periodically heated and rolled by a heating furnace, and the tissue production is more flexible. If there is no furnace between the continuous casting machine and the rolling mill, only the induction heater will replenish the continuous casting billet. This arrangement must require strict matching of steelmaking and rolling capacity. The cold billet that is produced when the rolling mill fails can only be taken out, and the production organization is difficult. It is only suitable for several specifications with equivalent hourly output. If a small size product is rolled, a considerable portion of the cold billet may be drawn. The advantage is that the investment is saved, there is no billet span and heating furnace. The core of the direct rolling process without induction heating is to cut the cutting point at the critical point of solidification, and move the conventional cutting point forward to increase the temperature of the continuous casting billet. Through computer simulation, the temperature distribution of the continuous casting billet at the cutting point section is 950 ° C on the surface and 1275 ° C in the core. The slab after fixed-length cutting is transported on the roller conveyor within 2 min, and the temperature drop should be less than 50 °C. If the roller path is long, the heat shield can be added, and the temperature of the steel billet on the inner surface of the heat shield can be restored. The average temperature of the steel billet section to the mill inlet can reach 1000-1050 ° C, which meets the rolling requirements. Since continuous casting can not guarantee the production of defect-free billets, the direct rolling technology can only be used for rod and wire production lines of carbon steel and low alloy steel.

Figure 1 Induction heating and direct temperature rolling