Thyssenkrupp Steel has resumed trial operations at hot strip mill 4 at its Duisburg site following extensive repair and modernization work after a fire damaged the facility in October 2025.
The incident, caused by a deflagration in the furnace area, resulted in damage to the furnaces and parts of the roof structure. Since then, the affected equipment has been repaired or replaced, while additional technical upgrades were implemented to improve plant availability and process stability.
The associated continuous casting line had already resumed operations in December 2025.
Hot strip mill 4 is a key part of Thyssenkrupp Steel’s production network and manufactures a wide range of hot-rolled flat steel products, including high-strength and premium grades for the automotive, engineering, construction, and energy sectors.
The company said the restart restores one of its most advanced production networks, supported by the refurbished continuous casting line and a new digitalized slab logistics system.
According to Thyssenkrupp Steel, the mill offers high production flexibility, precise dimensional control, and superior surface quality, enabling the company to meet increasing customer requirements for advanced steel applications.
Thyssenkrupp Steel is Germany’s largest flat steel manufacturer, based in Duisburg. The company specializes in high-quality flat carbon steel and serves diverse global industries, including automotive, packaging, energy, and construction.