Recently, the Double High-Speed Bar Project of Ulanhot Steel of Jingye Group succeeded in the hot test run and entered the stage of fulfilling the expected output and efficiency comprehensively, laying a solid foundation for the upcoming production of deformed steel bars according to the new national standard. For the project, MCC Capital Engineering & Research Incorporation Limited (CERI) was responsible for the overall technology, engineering design and supply of the core equipment and electric control system. 

The Project has a design capacity of 1.5 Mt/a and a stable rolling speed of 45 m/s, mainly producing Φ10–22 mm hot-rolled ribbed bars. CERI's profound attainments in process technology innovation, the top level of core equipment supply, excellent ability in electric control system integration and efficiency strength in project management and execution were highly recognized and praised by Ulanhot Steel of Jingye Group. 

I. Innovative process technologies 

The finishing rolling area for double high-speed bars innovatively adopts the "2+2+2" process layout, which can realize more accurate low-temperature controlled rolling and more efficient staged controlled cooling. On the premise of meeting the requirements of the new national standard, i.e. GB 1499.2-2024, for hot rolled steel bars, the comprehensive production cost is cut, the cost reduction and efficiency improvement for the production line are enabled, and the market competitiveness of products is enhanced. 

The flexible and modular rolling concept, single pass system and separate drive technology of finishing rolling mills are adopted to realize a new mode of production with one pass for full-specification products, which solves problems such as low product precision, low production operation rates and insufficient flexibility. The production operation rate is greatly increased to more than 90%, and the production cost is reduced. 

The precise low-temperature finishing rolling and the controlled rolling and cooling process of staged water cooling after rolling are adopted to effectively reduce alloy consumption, provided that the products meet the "Jingye Blue" requirements, thus realizing green production of hot-rolled steel bars with less alloy. 

II. Advanced core equipment 

The finishing rolling mill of the Project adopts the high-precision and ultra-heavy-duty CMM-III-310 modular line independently developed by CERI. For the modular rolling mill, the oil film bearing, a high-rigidity eccentric sleeve and an adaptive roll shaft system are specially designed, solving problems such as the high failure rate and limited coverage of product specifications in traditional low-temperature rolling of high-speed bars. The mill can fulfill low-temperature rolling at 750°C, effectively improving the rolling control level. 

The third-generation high-speed steel feeding system of CERI is adopted in the Project. In view of the problems such as clamp marks at the tail during high-speed steel feeding and stability of the rotating hub, the multiple-length rotary shear and tail gripper are upgraded to reduce the wear of roll collars and improve the steel carrying capacity. The newly upgraded oil-air lubrication and water cooling system of the rotating hub system ensures the stability of the rotating hub operation. The system has a stable speed ​​of strip movement of 45 m/s, greatly improving production efficiency. 

III. Reliable control system 

The high-speed modular rolling mill speed compensation control system, water-cooling closed-loop temperature control system, high-speed multiple-length rotary shear control system, high-speed steel feeding control system and adaptive periodic cooling bed control system independently developed by CERI are applied to improve the stability of the rolling line operation and the electrical control level of high-speed bars. 

Rolling impact compensation and cascade compensation models are developed innovatively to realize dynamic compensation variable-extension control of rolling. The independently developed i-PEDM control technology is adopted to eliminate the problem of low multiple-length measurement accuracy caused by speed fluctuation, fulfilling a multiple-length accuracy of rolled pieces of less than +/-60 mm. The stability of the high-speed steel feeding control system is improved using the high-speed bar braking control model and adaptive steel feeding control model. 

IV. Efficient project management 

The contract for the Double High-Speed Bar Project of Ulanhot Steel of Jingye Group was signed in January 2024, and steel rolling was completed successfully on July 24, creating a project construction record of putting the whole line into production in only six months.