SMS group has successfully completed the upgrade to the hot strip mill at Pangang Group Panzhihua Steel and Vanadium Co., Ltd. in China, by far the most challenging project of this kind in recent years. The results are convincing: Pangang Group is proud of its new, considerably higher hot strip production capacities. In addition, the product portfolio has been expanded significantly.
We are proud to have carried out this extremely demanding modernization so successfully and on schedule with SMS as our main partner. We greatly appreciate the fact that SMS was committed to the project at all times, even beyond its contractual obligations. The project is also regarded by top management as a lighthouse project for modernization in the Chinese steel industry and beyond.
The revamped hot strip mill does not need to fear comparison with a new plant. Besides processing of high-strength grades, Pangang Group can also roll hot strip to a final thickness as thin as 1.2 mm and thus meet the growing demand for thin hot strip. The new finishing mill operates at a higher rolling speed, leading to a significant increase in the production capacity. The upgrade measures also resulted in an improved strip quality and ensured higher plant availability.
The centerpiece of the modernization project is the new seven-stand finishing mill. Its modular stand design meant it could be well integrated into the available space. As a result, it went into service within a very short time. The main actuators that influence the product quality are the hydraulic roll gap adjustment system (short stroke HGC) and the proven CVC® plus technology (continuously variable crown) for combined shifting and bending of the work rolls. The X-Pact® Profile, Contour and Flatness (PCFC®) process model was an integral part of the scope of supply. Working in conjunction with the actuators, it ensures a stable rolling process with reliable adherence to strip thickness and flatness tolerances and means that even thin hot strip can be rolled reliably.
The new laminar strip cooling system which ensures equally high and flexible cooling rates has a substantial influence on the product quality and in particular on the desired material properties. The two new hot strip downcoilers guarantee impressively reproducible coiling quality from head end to tail end of the strip. In addition to this new equipment, SMS group’s scope of supply also included the adaptation (upgrade) of the existing fluid systems.
Only two shutdowns required
Since Pangang Group Panzhihua Steel and Vanadium Co., Ltd also collaborated on the hot strip mill revamp with its own scope of supply, the special challenge for the technical project management team was to ensure that the measures intermeshed smoothly and were well coordinated.
Thanks to skillful planning, only two plant shutdowns were required for the upgrade project. Major revamp activities were completed while production was still ongoing.
During the first shutdown in September 2021, the laminar cooling section was renewed and a bridging roller table installed downstream of the existing finishing mill. This bridging roller table enabled foundation work to be carried out for the new finishing train during ongoing production. During the second shutdown in October 2022, the new finishing mill was installed in line, downstream of the remaining finishing mill, and the coiler group consisting of two stationary downcoilers was replaced. At the same time, the existing finishing train was dismantled and the entry section relocated.
The task of the project to implement a complete new finishing mill, laminar strip cooling and downcoilers in the existing 1450 mm hot strip mill with minimized shutdown times was executed in an excellent manner by the involved parties. Thanks to the new equipment and technology by SMS, Pangang Group Panzhihua Steel and Vanadium has reached their project targets to produce high strength steel grades, increased the production and improved the strip quality.