Method for continuously casting 16m square billet directly-rolled bar

Abstract

The invention provides a method for continuously casting a 16m square billet and directly rolling a bar, which comprises the following steps of: in a post-cutting conveying stage, mounting an electromagnetic induction heating device on a straight rolling roller way, heating a steel billet to 920-940 DEG C, controlling the temperature rise rate of the electromagnetic induction heating device to be 7-10 DEG C / s, and controlling the rod temperature difference of the steel billet to be below 35 DEG C; the conveying speed of the straight rolling roller way is increased to 4-5 m / s, a heat preservation cover is arranged on the straight rolling roller way, the steel billet is wrapped and covered with the heat preservation cover, and heat preservation and heat insulation are conducted on the steel billet; the waiting position of the steel billet on the roller way is arranged in the heat preservation cover; by optimizing the production process, the process steps, the process parameters and the like, the continuous casting 16m square billet direct rolling bar is realized, the oxidation burning loss is reduced to 0.3%, the coal gas consumption after direct rolling is reduced to 0m, the coal gas saved by the 16m steel billet per ton of steel can generate electricity of 58kW. H, and the electric quantity per ton of steel can be saved by about 3kW. H after the heating furnace stops running.

Description

technical field [0001] The invention relates to the technical field of continuous casting and direct rolling, in particular to a method for continuous casting of 16m square billet and direct rolling bar. Background technique [0002] At present, the bar production line is equipped with a double regenerative walking beam heating furnace, which has realized two kinds of hot and cold billets of 165 × 165 × 12000mm and 165 × 165 × 16000mm. After being heated by the heating furnace, they enter the rolling line for rolling production. The heating process of the double regenerative walking beam heating furnace increases the oxidative burning loss of the steel billet, and the oxidative burning loss per ton of steel reaches 0.9%. The heating process needs to consume gas, and the gas consumption per ton of steel for the hot billet is 150m 3 About 230m of gas consumption per ton of cold billet steel 3 about. In addition, the heating process of the regenerative walking beam heating fu...

AI Technical Summary

Problems solved by technology

At present, for a 16-meter billet, after calculation, the temperature of the continuous casting billet is about 1050°C, the continuous casting casting speed is 4 m / s, and the temperature drop is 0.7°C per second. The casting process is about 4 minutes, and the temperature drop of the billet head is 168°C. , the temperature at the head of the billet dropped to 882°C, and then passed through the 174-meter straight rolling table, the temperature dropped by 60°C. The steel billet temperature lower than 900°C leads to: 1) The biting current of the rolling mill exceeds the rated current, which has a large impact on the motor and reducer. In addition, the too low head temperature causes uneven deformation of the head of the rolled piece, which is prone to cracking 2) The 16-meter steel billet has not been heated or reheated, and there is a serious problem of uneven temperature distribution in the length direction. The extension and width of each part of the rolled piece are inconsistent during rolling, and the stacking relationship of the rolling line fluctuates greatly. , the three-cut and three-branch negative difference gap is large, and the overall negative difference fluctuates greatly; 3) The 16-meter direct rolling has no buffering and coordinating effect of the heating furnace, steelmaking and steel rolling are rigidly connected, the production rhythm does not match, and the production affects each other. To avoid cold slabs, it is necessary to develop a new flexible joining process; 4) The weight of the direct rolling slab affects the cut loss of the finished product and the overall size is large, and there are many factors affecting the weight of the slab, including the density of the slab, the length of the slab, and the cross-sectional area of ​​the slab. The difference in casting speed will have an impact on the above factors, but at the current stage, only the length of the billet can be controlled, so the accuracy of the actual weight control of the direct rolling billet is relatively low

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