Members of the research team measure the vibration values of the rolling mill’s main reduction gearbox.

Project Profile

Recently, Shougang Zhixin’s “SUPER MILL Innovation and Practice of High-efficiency High-silicon Steel Tandem Rolling Technology” Project won the first prize at the 2023 Shougang Science and Technology Awards. After eight years of R&D, the six-stand, six-roller mill and its supporting rolling technology have surpassed traditional tandem rolling production limits to successfully achieve industrialized production, injecting brand-new momentum into the development of China’s “new productive forces” and achieving the “dual carbon” goals. As the saying goes, “things seem ordinary, but they are very strange; success seems to be achieved effortlessly, but it is the result of hard work”. All the core innovative technologies of the “SUPER MILL” six-stand cold tandem rolling mill were independently developed and integrated by Shougang, many for the first time in the world. The project team blazed a new trail with the indomitable persevering spirit of “remaining strong after experiencing thousands of hardships” and the fearless attitude of “continuing to advance despites all difficulties” to ultimately achieve a significant breakthrough from nothing to something and from “0” to “1”. While highlighting Shougang’s shining “golden business card”, the project has also contributed “Shougang strength” to technological advancements and high-level scientific and technological self-reliance and self-improvement in the steel and iron industry.

A Story of Breakthroughs

Striving for Excellence without Seeking Recognition

The call to action is urgent. The “dual carbon” goals have become the inevitable path for China’s strategic layout of modernization. High-grade non-oriented silicon steel, as the core material for manufacturing the drive motors and key components of new energy vehicles, and high-grade oriented silicon steel, as the core material for transformer cores and critical equipment for power grids, are of paramount importance. On the one hand, as the market demand for high-grade silicon steel explodes, the efficient and energy-saving development trend has also decided the development trend towards silicon steel with higher silicon content and less thickness. However, the silicon content of electrical steel in production directly affects its rollability. As the silicon content increases, the brittleness and deformation resistance of silicon steel sheets multiply, leading to a sharp deterioration in processability and a gradual increase in rolling difficulty, which poses significant challenges for industrial development. On the other hand, although the stable rolling of high-silicon steel grades has been achieved through long-term research, production volumes are limited and have failed to meet the growing market demand due to objective conditions such as rolling methods and production processes.

It is high time to seize the opportunity. The “SUPER MILL Innovation and Practice of High-efficiency High-silicon Steel Tandem Rolling Technology” Project consists of the design and construction of the first specialized production line in the world for electrical steel used in new energy vehicles. The “SUPER MILL” six-stand cold tandem rolling mill, the first “Pillar of a Great Power” in the world, has attracted widespread attention from both inside and outside the industry. Its core technologies were independently developed and integrated by Shougang, with the dimension control, plate shape control, product performance, and operational efficiency reaching the world-leading level. As the world’s first high-speed cold tandem rolling mill capable of warmly rolling high-silicon thin-specification electrical steel, the title “world’s first” evokes the unimaginable hardships and tribulations endured by the project team. They explored the “forbidden zone” of processes, filled in industry “blanks”, made breakthroughs in technological “bottlenecks”, and carved out a new path where no paths existed before.

Innovation brings unity and reform seeks progress. In creating the first six-stand, six-roller cold tandem rolling mill for high-silicon silicon steel, Shougang needed to develop and pioneer a brand-new technological path, along which it encountered numerous obstacles. At the beginning of the project, the severe epidemic control situation across regions significantly impacted the equipment debugging progress and even threatened the suspension of the project. Faced with the impending halt, all project participants refused to give up: “Rowing against the current, you either forge ahead or drift downstream. The project can’t be stopped. We must continue! We shall research materials, find data, and take charge!” Led by members of the project team, a closed-loop debugging team was formed. Despite time differences with foreign experts, the team members discussed debugging plans with them at night and continuously explored the equipment with notes and data during the day. From threading the entire line to cold and hot load tests, the team successfully completed the unit debugging tasks step by step. Countless stories of overcoming obstacles emerged during this process. The project team put forward, designed, and modified over 100 significant optimization suggestions regarding production processes, product quality, operation and maintenance, energy conservation, and consumption reduction.

In the initial stages of experimentation, the challenges of edge cracking and belt breaking during the rolling of high-silicon steel undoubtedly dampened the spirits of the entire project team. Faced with this “obstacle”, the project team devoted themselves to the production line, collected various data in an all-round way, systematically analyzed the rolling parameters, and studied the appearance of fractures on site. They conducted simulated rolling specifically targeted at belt breaking while starting up the mill. Whenever a new insight emerged, the core members of the team would repeatedly discuss and carefully verify it. From the very beginning, they adopted an “indirect strategy” by using other steel grades as rolling leading tapes to significantly reduce the number of start-ups for raw material plates, as well as a “shock strategy” by focusing all efforts on “precision blasting” the problem, delivering precise strikes against the “obstacle”.

Perseverance Serves as the “Body” and Daily Innovation Serves as the “Path”

As the red sun rises, its path is illuminated with great brilliance. The innovation of SUPER MILL’s high-efficiency high-silicon steel tandem rolling technology increases efficiency more than eightfold compared to traditional production processes. However, as efficiency is enhanced, risks also multiply. There are hundreds of technical nodes in the whole rolling process and even a slight deviation in one link can lead to the fracture of the entire steel strip, resulting in a complete loss. The project team did not pursue immediate interests or allow themselves to be satisfied with small achievements, but systematically overcame multiple challenges including rolling speed, strip shape precision, cooling control, and the brittle fracture of steel strips. In this project, the research team obtained a total of 16 invention patents, making significant contributions to the technological advancement of the industry and the implementation of the national green, low-carbon, and high-quality development strategy.

Innovation is endless. We should pursue perfection and climb the peak. Currently, a new round of scientific and technological revolution and industrial transformation is accelerating. Developing new productive forces is the only way to build core competitiveness and achieve high-quality development. The “SUPER MILL Innovation and Practice of High-efficiency High-silicon Steel Tandem Rolling Technology” Project marks a brand-new starting point. Shougang Zhixin will continue to focus on aspects such as leading technological innovation, digital empowerment, and green and low-carbon development, strive to develop new productive forces according to the local conditions, and inject continuous momentum into creating a Shougang scenario for China’s modernization!