On October 31, 2024, Zhoukou Steel's 5600 mm wide heavy plate roughing mill, the world's widest plate mill independently designed and supplied by MCC Capital Engineering & Research Incorporation Limited (CERI), commenced hot commissioning with the successful rolling of its first wide heavy plate. This milestone represents a significant advancement in the global steel manufacturing sector, signaling the dawn of a new era of 5600 mm wide heavy plate rolling mill technology in the world.

The heavy plate rolling mill is critical in the heavy plate rolling and forming processes. The products produced by this mill find extensive applications in various industrial sectors and infrastructure projects that are integral to both the defense industry and the national economy. Extra-wide heavy plates play a vital role as strategic materials and core raw materials for a variety of important equipment. They are primarily utilized in aircraft carriers and large vessels, large-diameter oil and gas straight seam welded pipes, structural steel for offshore drilling platforms, containment structures for nuclear power plants, large dam gates, high-pressure boiler steel plates for power plants, and large oil and gas tanks, among other applications. 

Proactively Developing Heavy Plate Rolling Mills 

There are thirty-one operational or under-construction 5000mm heavy plate production lines worldwide, with China having seven of these lines. In the realm of 5500mm rolling mills, China operates only one 5500mm + 5000mm double-stand heavy plate rolling mill at Ansteel, which has increasingly proven inadequate to meet the surging market demand for extra-wide heavy plates. CERI and its Chinese peers have successfully completed the design and supply of 3800mm and 4300mm heavy plate rolling mills; however, no breakthrough has been achieved in the field of 5000mm heavy plate rolling mills. All existing 5000mm heavy plate rolling mills in China rely on foreign technology, which not only incurs substantial costs but also poses the risk of technology barriers. 

CERI is the earliest company engaged in heavy plate engineering design in China, ranking among the top players within China MCC's "National Metallurgical Construction Team". Leveraging its robust technology and extensive engineering experience in plates, CERI adheres to top-level design principles and action manuals, facilitating continuous improvement, optimization, and innovation. The heavy plate team consistently aligns with the strategy of the national metallurgical construction team, dedicated to the mission of building a country with a strong metallurgical system. CERI has accumulated substantial technical expertise through numerous research and development projects, including "High-performance Heavy Plate Rolling Mill Equipment Technology Development", "Super-Long Plate Rolling Mill Process and Equipment Technology", and "Key Technology Development for Ultra-wide Heavy Plate Rolling Mill Equipment". The experience gained from domestic heavy plate rolling mill upgrade projects—such as Baosteel's 5000mm heavy plate rolling mill and Echeng Steel's 4300mm finishing mill—along with the design of Yingkou Jinghua Steel's 3800mm heavy plate double-stand rolling mill and Guangxi Steel's 3800mm heavy plate double-stand rolling mill. Additionally, we proactively conduct research and development in ultra-wide heavy plate rolling mills. 

With advancements in heavy plate production technology, particularly TMCP rolling and cooling control technology, the yield stress of rolled pieces has increased, and the application of single-pass large screw-down rolling has reduced bouncing during the rolling process. To produce extra-wide steel plates with higher dimensional accuracy, it is essential to develop wide heavy plate rolling mills that feature high rolling force, high stiffness, strong shape control capabilities, and substantial torque. To address these challenges, CERI has established a dedicated research group for wide heavy plate rolling mills, composed of technical experts, researchers from the Research Institute, and engineers experienced in heavy plate rolling mill design. This team conducts comprehensive research with major steel companies to understand the usage of wide heavy plate rolling mills, thoroughly examining the actual performance of various structural components. They collaborate with rolling mill technology and equipment experts to perform adequate demonstrations, assess various technical challenges, finalize the wide heavy plate rolling mill model, and subsequently formulate a detailed R&D plan. This plan includes: using CERI's rolling specifications and procedures to determine the parameters such as rolling force and main motor of wide heavy plate rolling mills based on the requirements of the wide heavy plate product mix; utilizing newly developed calculation software to determine parameters such as mill stiffness, housing, and roll system of wide heavy plate rolling mills according to the shape requirements of these plats; employing the heavy plate rolling mill design system for theoretical calculations and 3D design of each component and system, and conducting finite element analysis and dynamic simulation analysis for correction to ensure reliable design. The newly developed extra-wide heavy plate rolling mill features stands with ultra-high stiffness, a fast electric screw-down device combined with a hydraulic AGC device, and innovative work roll bending and shifting devices that enhance shape control capabilities. Additionally, it includes a high-wear-resistance elevation adjustment device and a high-power main motor designed to achieve large transmission torque. This equipment meets the requirements of the "low temperature controlled rolling" process. The electronic control system is integrated to facilitate multifunctional thickness control, plane shape control, and plate shape control for the wide heavy plate rolling mill. 

Cooperation Yields the World's Most Advanced Heavy Plate Mill 

In 2023, HBIS planned to construct a 5600mm + 5500mm double-stand heavy plate rolling line with a designed output of 2.6 Mt/a. This initiative aims to achieve structural adjustments, transformation and upgrade, and promote high-quality development, ultimately creating the world’s most advanced and competitive green intelligent heavy plate flagship factory. The roughing mill is the only equipment globally capable of producing plates with a width exceeding 5500mm, and HBIS plans to adopt domestic design and manufacturing. 

CERI and CITIC Heavy Industries have collaborated closely, conducting multiple technical exchanges with HBIS and effectively showcasing CERI's technological research and development achievements and technical advantages, and CITIC Heavy Industries's manufacturing strength in the ultra-wide heavy plate rolling mill sector. As a result, our team was fully recognized by HBIS. The company engaged CERI for the design and supply of the 5600mm roughing mill, mill run-in and run-out tables, exit manipulators, and other equipment. The technical design parameters of the 5600mm roughing mill are at the forefront of global standards. Raw Material Specifications: thickness: 220mm, 260mm, 320mm, 370mm, 460mm; width: 1500mm to 2800mm. Product Specifications: thickness: 6mm to 150mm (300mm); width: 900mm to 5,300mm (maximum width of finished products rolled by the roughing mill is 5450mm). The mill features integrally cast large-section stands with a stand post sectional area exceeding 10,000 cm², a maximum roll gap of 1100mm, and two main motors rated at AC9000kW. The maximum rolling speed is 5.7m/s, with backup roll specifications of φ2400/φ2200 x 5450mm made from Cr4 material. The work roll specifications are Φ1240/φ1140 x 5600mm, with a maximum bending force of 4000kN. When compared to the primary 5000mm mills operating domestically and internationally, the main design technical parameters of this mill are at the world's leading level, establishing it as the true "king of rolling mills". 

This 5600 roughing mill incorporates a range of state-of-the-art technologies: 

1. The mill's housing utilizes wear-resistant and corrosion-resistant technology to extend its lifespan by at least twofold. 

2. The screw-down device operates at a lifting speed 1.4 times faster than that of conventional mills, significantly improving the rolling production rhythm.  

3. The new breast roll change mode reduces the roll change time by approximately 50%.  

4. The mill adopts multi-functional fast roll change technology. The layout of the roll change area is simplified and the roll change time is decreased by about 10%. 

5. The innovative multi-guide roll bending technology further enhances the reliability and plate shape control capabilities of the bending cylinder. 

6. The mill features a new type of guide device that further protects the guide and prevents steel plates from impacting it.  

7. The main transmission device is equipped with a hydraulic safety coupling positioned between the universal joint on the motor side and the intermediate shaft of the universal spindle. The hydraulic safety coupling disconnects when the transmission torque exceeds a predetermined value, thereby protecting the transmission system.  

8. The mill's transmission spindle includes a wired monitoring device that accurately captures the mill's operating status. This device monitors failure-prone areas and enables intelligent early warnings, failure diagnosis, and lifespan prediction, facilitating full lifecycle maintenance management. 

Powerful Alliance Forges the King of Rolling Mills 

The main components of Henan Zhoukou Steel's 5,600 roughing mill, including the housing and backup rolls, were manufactured and assembled by CITIC Heavy Industries. Both the smelting and manufacturing parameters meet the extreme standards for metallurgical equipment manufacturing. 

1. Large-section housing casting technology: The net weight of a housing exceeds 450 tons, with 860 tons of molten steel used for seven-ladle combined casting, reaching the extreme casting limits. 

2. Vacuum melting and vacuum casting technology for large forged steel backup rolls: The backup rolls have a net weight of nearly 270 tons, made from 500 tons of steel ingots. Molten steel's chemical composition, vacuum degree, and temperature can be precisely controlled to reduce oxidation while eliminating 99% of impurities and gases, thereby enhancing the overall performance and quality of steel ingots. 

3. Composite forging technology for large forged steel backup rolls: The world's largest 18,500-ton free-forging hydraulic press is utilized to process oversized steel ingots, ensuring thorough forging and compaction in the core area, thereby guaranteeing the quality of large forged steel backup roll ingots. 

4. Differential temperature heat treatment and top-support combined ultra-heavy grinding technologies for large forged steel backup rolls: It achieves an overall accuracy within 0.02mm. 

5. Inspection technology for tapered surfaces of oil-film bearings in large forged steel backup rollers: Utilizing special high-precision taper measuring instruments combined with isothermal measurement control techniques using outside micrometers, this technology ensures accurate measurement of tapered surfaces of oil-film bearings for large forged steel backup rolls. 

Working Together to Reshape the Power of Steel 

CERI's heavy plate project management team has implemented meticulous organization throughout the processes of equipment design, manufacturing, installation, and commissioning and anticipated potential issues at each stage, ensuring the project's success. 

Leveraging a robust quality assurance system, CERI adheres to world-class equipment manufacturing standards as its benchmark. To guarantee manufacturing quality, timely progress, and smooth commissioning, CERI provided technical support for equipment manufacturing during the whole process and employed foreign supervision experts to monitor the quality of the rolling mill equipment during manufacturing. From the casting of 860 tonnes of molten steel to precision machining and equipment assembly, stringent inspections have been conducted. 

Under the careful coordination of the project management team, team members participated in the entire process of onsite installation and commissioning. The hoisting of the mill housing began in mid-September, and all electrical, mechanical and hydraulic installations were completed in just 45 days, setting a new record for rolling mill installation in the wide heavy plate sector. Moreover, both single-machine commissioning and joint commissioning created new records for the commissioning of 5000mm plate mills in China. Ultimately, the world's widest heavy plate rolling mill—Zhoukou Steel's 5600mm wide heavy plate roughing mill—successfully completed its hot commissioning on schedule.