Qualified molten steel smelted by steelmaking converter → cast into a billet by continuous casting machine → secondary heating in the heating furnace of rolling mill → rolled into steel by the rolling mill.
Direct rolling process:
the billet is poured by the continuous casting machine → directly into the rolling mill → rolled into steel.
Pollution reduction, carbon reduction, energy conservation, emission reduction, and green development have put forward extremely high requirements for green manufacturing in the iron and steel industry. Compared with the traditional process, the continuous casting billet hot feeding direct rolling process technology can not only reduce the oxidative burning loss of the heating furnace, but also reduce the emissions of carbon dioxide, sulfur dioxide, and nitrogen oxides, and save the gas of the heating furnace, which is of great significance for energy saving and emission reduction. It can be called an industry disruptive technology.
In response to the national call for energy conservation, emission reduction, and green and low-carbon development, Changgang started the technological transformation of continuous casting billet direct rolling in 2016. After several years of technical reserve and feasibility demonstration, the continuous casting billet direct rolling technology was established on March 27, 2020. On the basis of the successful transformation of the No. 7 continuous casting machine, the direct rolling of the No. 8 continuous casting machine was carried out.
After the completion of the two-phase transformation, the cast slabs of the No. 7 and No. 8 continuous casting machines can be sent to the bar and bar wire production lines for rolling, and the bar wire production line can also be switched between high bar and high wire production lines, forming Connected and flexible production processes.
The project mainly adopts the high-efficiency continuous casting machine speed-up technology (including the design of the tundish flow field, the transformation of the mold vibration device, the automatic water distribution technology of the secondary cooling section, the matching transformation of the mold, the matching transformation of the continuous casting machine cutting method, etc.) Casting billet heat preservation and rapid conveying technology, continuous casting billet temperature balance control technology, etc. At present, the direct rolling of HPB300, HRB400E, and HRB500E steel bar products has been realized.
The technology is at the international advanced level, the project acceptance data is complete and accurate, and the technical performance indicators obtained during the project operation meet the performance and functional requirements of the technical agreement and feasibility study report, forming a process equipment technology integration with independent intellectual property rights. , built a dual-casting machine multi-rolling line direct rolling demonstration production line, which has significant energy saving, emission reduction, and carbon reduction effects, has good environmental and carbon reduction benefits, has a demonstration and leading effect in the industry, and has broad prospects for promotion and application.