The characteristic of billet heating of high-speed wire rod mill is strict temperature system. The temperature shall be uniform, the temperature fluctuation range shall be small and the temperature value shall be accurate. The common requirements for billet heating are as follows: less oxidation decarburization, no distortion of billet, no overheating, etc.
The high speed wire rod mill has large billets and long billets. Therefore, whether the heating temperature of the billet is uniform is particularly important. The ideal is that the rolling temperature of the whole billet should always be the same when it reaches the first rolling mill.
To do this, the temperature at both ends of the billet is often raised. The head of the billet first contacts the roll, resulting in large temperature drop. The time between the reheating furnace and the first rolling mill after the billet tail is discharged is longer than that at the front of the billet, and the temperature of the first rolling mill is required to be the same. Therefore, the heating temperature at both ends of the billet is 30~50 ℃ higher than that at the middle.
The strict requirements on heating temperature and rolling temperature of steel billet are to meet the needs of controlled rolling in high-speed rolling mill and to control the final performance of wire rod.
