Research Of Continuous Casting-Direct Endless Rolling For Wire Rod And Bar

Wire rod and bar are widely used in the industrialization, urbanization, and modernization of China. Many weaknesses exist in traditional production of wire rod and bar, such as high energy consumption, low metal yield, and instability in rolling, et.al. Welding endless rolling technology which is introduced from abroad presents some problems in welding quality and failure rate during the application in several steel mills.Continuous casting-direct endless rolling technology (CC-DER), which is used for production of wire rod and bar, was presented in this paper. Process, key equipments and layout of production lines were offered. Based on the casting and rolling processes in a steel mill, temperature field of casting billet and casting speed were studied with ANSYS, and economy analysis for CC-DER was discussed, too. Main research work in this paper conclude as follows.1. The concept of CC-DER was presented. Compared to traditional production of wire rod and bar, CC-DER has many advantages in energy consumption, metal yield and stability in the production.2. Based on the modified model of heat flux, in which air gap was taken into account, the temperature field of billet in casting process was studied by ANSYS. The deviation between numerical simulation result and measured results is within±1.2%.3. Influence of main parameters in casting to the temperature field of billet was studied in this paper. Average temperature of billet at cut-off point decreases with the increasing of effective length of mould and water flow in secondary cooling zone, and increases rapidly with the increasing of casting speed.4. Influence of main parameters in casting to the casting speed was also studied. When the thickness of water gap in mould is4mm and the velocity of water flow is lOm/s, the biggest casting speed could be improved to2.9m/min. The biggest casting speed could increase for0.3m/min as the effective length of mould increases for100mm. The thickness model of air gap in mould was deduced in this paper, which sets the basis to modify the simulation in the future. Suggestions were proposed for the application of CC-DER in this mill, and the biggest casting speed could rise to3.7m/min.5. A CC-DER line with annual production of300thousand tons could save22.5thousand tons of coal in heating,4500tons of metal in burning,1500tons of metal in cropping and6000tons of steel for short-orders, which could reduce the cost for50million RMB per year. The weakness of CC-DER is the large loss of benefits for roll changing and accidents.