The continuous casting workshop of Chifeng Zhongtang Steel Plant has transformed innovation into core competitiveness, realizing the increase of the pulling casting speed in continuous casting of the 1020*200 section of the three-machine three-stream continuous casting machine from 1.4m/min to 1.9m/min, and writing a new chapter of high pulling speed of Zhongtang Special Steel with practical actions.
Facing the severe situation, Deputy General Manager Yu Guobin bravely challenged and proposed the topic of efficient continuous casting, and organized the technical personnel of the steel plant to conduct in-depth research and discussion. The personnel present expressed their willingness to practice survival skills in “reducing costs and increasing efficiency”. According to the idea of
In the face of the problem, the technical staff volunteered to offer suggestions and set up a process group, with Gao Yu responsible for the theoretical calculation process design of high drawing speed 1.9m/min, the equipment group, with Meng Liqun responsible for the optimization of high drawing speed 1.9m/min equipment, and the production group, with Qiao Zhenqian responsible for the rhythm coordination of continuous casting drawing speed and converter production.
By consulting a large number of continuous casting high drawing speed references and simulating the calculation of the continuous casting molten steel solidification model, the secondary cooling water volume of the main pipe of the three-machine three-stream casting machine can be improved by modification to increase the drawing speed crystallizer full roll water volume gap, but the water volume of the secondary cooling zone branch pipe has reached 100% at a drawing speed of 1.7m/min. How to compensate has become a “roadblock” to the progress of the project.
After repeated deliberation, a bold design emerged in the mind of workshop director Gao Yu. Using the compressed air channel of the existing aerosol cooling box, a branch pipe was introduced on the main pipe to connect with the box branch pipe, and the stop valve was used to switch the ventilation when producing the steel type and the water when producing the steel type 195 micro-aluminum. This can solve the problem of steel type switching and the problem of branch pipe compensation water. According to the idea of
The high drawing speed inevitably brings hidden quality risks. For this reason, Dong Zhiqiang, the director of the steelmaking plant, continuously tracks the fluctuations of key parameters such as the temperature difference between the inlet and outlet water of the crystallizer, the consumption of protective slag, the surface quality of the ingot, and the low-magnification structure after the drawing speed is increased, and proposes and requires the continuous casting workshop to take key measures. The workshop director Gao Yu has formulated the control rules for the key processes of high-speed continuous casting, optimized the control parameters of the secondary cooling water meter, and summarized the “three reductions and three non-reductions” working method for high-speed drawing. At the same time, the backbone was actively organized to carry out 35 high-speed drawing quality risk identifications in the post-process, and 12 identifications and summaries were used as quality prevention systems. The qualified rate of first-class low-magnification products reached 95%.
Under the guidance of high casting speed in continuous casting drawing technology, casting machine production presents diversified services, all of which can meet the 1450 hot rolling production line with red roller delivery. The original three-machine three-stream design produced 8,600 tons per day, and the high-speed drawing daily output was 11,000 tons. Innovation has brought together the various professions of steelmaking, continuous casting, and rolling, effectively promoting the continuous improvement of professional and technical strength. Continuous casting and high-speed drawing are the links that bring about a comprehensive improvement in cost, quality, and efficiency. Data shows that compared with the converter before the speed increase, the steel tapping temperature was reduced by 5°C, saving 4.8 yuan per ton of steel; the output of the casting machine increased by 120.5 tons/hour, and the energy cost was saved by 1.2 yuan/ton; the temperature of the billet for red delivery of the rolling roller was also increased by 6°C, and efficient continuous casting brought high-efficiency returns.
