Billet Selection and Heating of 0.8MTA Hot Rolled Wire Rod Mill Production Line
In this Hot Rolled Wire Rod Mill production line because of the close distance between the continuous casting machine and rolling line, the hot billet is used as raw material and hot charging process of continuous casting billet is adopted.
The Advantages of the Hot Charging Process Used in a Hot Rolled Wire Rod Mill are as Follows:
1. Reduce the fuel consumption of the reheating furnace and increase the output of the reheating furnace.
2. Reduce heating time, and then reduce metal consumption.
3. Reduce the stock of billets, plant area, and lifting equipment, etc., making production costs lower.
4. The production cycle is shortened by the hot charging process and omitting preheating section. According to the heating system and requirements of different steel grades, the billet is heated to 1050 C ~ 1250 C in the heating furnace. Because the hot charging process of continuous casting billet is adopted in this design, the preheating section in the typical three-stage heating system of preheating, heating and soaking are omitted, and only the heating and soaking section is taken. The billet is heated rapidly in the heating section. The surface temperature of the billet is slightly higher than the tapping temperature, and the homogenization of the billet temperature is completed in the soaking section.
Descaling of Billet
High-pressure water descaling device is used in this design. The heated billet is pushed out by the tapping roller and the oxide scale on the surface is removed by high-pressure water to improve the surface quality of the rolled piece and facilitate the biting of the rolled piece.
Rolling of Billet
The billet is transported from the roller to the roughing mill for rolling. When the rolling mill fails, the clamping shears set in front of the roughing mill will cut off the billet entering the roughing mill, and the slab after the clamping will return to the reheating furnace to keep warm for rolling. A flying shear and a clipping shear are installed behind the roughing mill. According to the technological requirements, the billet is rolled in roughing mill and intermediate rolling mill without torsion and tension.
The billet passes through side loopers and enters four cantilever pre-finishing mills arranged alternately in the horizontal and vertical direction for single-strand no-tension no-twist looper rolling. Finally, the billet enters the finishing mill through the pre-water cooling section, flying shear cutting head and tail, and side looper rolling. Ten 45 degree non-twist finishing mills are used in the finishing mill. High-speed single strand wire rod non-twist micro-tension continuous rolling of the rolled piece into high-precision wire rod is carried out in cantilever tungsten carbide small roll ring.
