On February 12, China’s first Gpa-grade steel six-roll single-stand cold rolling mill designed and supplied by Capital Engineering & Research Incorporation Limited (hereinafter referred to as CERI) was officially commissioned at Hunan Valin Lianyuan Iron & Steel Special New Materials Co., Ltd. The first coil of DP980 ultra-high-strength steel was successfully produced. This project marks the first instance in China of a six-roll single-stand cold rolling mill being used to produce Gpa-grade steel, successfully filling a critical technological gap. 

To meet the stringent requirements of rolling GPa-grade steel, CERI leveraged its three major technical strengths—stable rolling, precision rolling, and surface control—to develop a new type of small-diameter six-roll mill featuring high rigidity, high precision, and high stability. This mill achieves ultra-high rolling capacity, ultra-high thickness control precision, ultra-short head-tail out-of-tolerance, and ultra-premium shape accuracy, with all technical indicators reaching internationally advanced levels. CERI completely breaks the traditional approach of using multi-roll mills to produce GPa-grade steel, enabling large-scale, efficient, and high-quality production of GPa-grade steel. 

CERI overcame multiple challenges in the project and successfully developed three core innovative technologies. First, the roll system design with a small roll diameter, large rolling capacity, and high stability is adopted to ensure that the rolling mill has the ability to roll GPa-grade steel, and the maximum width-to-thickness ratio can reach 2000. Second, the line is tailored for the large-scale, efficient and high-quality production of Gpa-grade steel, including: compact unit layout to improve yield rate; specially designed emulsion cooling and lubrication system to meet the requirements for high-speed and high-load rolling under full pressure; surface cleaning technology to solve the problem of residual emulsion on the plate surface; automatic core rolling and binding device to improve automation level; fast second flow control to reduce head-tail out-of-tolerance. Third, an AI- and big data-driven intelligent process model enables real-time dynamic optimization of rolling parameters, ensuring consistent and uniform quality in every coil of steel strip and fully meeting the stringent standards of downstream manufacturing industries.