thyssenkrupp Steel restarts Hot Strip Mill 4 in Duisburg after 2025 furnace fire
- Trial operation at Hot Strip Mill 4 resumed after a deflagration and fire in the furnace area on October 24, 2025.
- Furnaces and parts of the roof structure were extensively repaired or replaced and targeted technical optimizations and modernizations were implemented.
- The associated continuous casting line returned to operation in mid‑December 2025.
- Hot Strip Mill 4 produces hot‑rolled and premium thin high‑strength steels for automotive (including e‑mobility), mechanical engineering, construction and energy sectors.
Incident and repairs
Trial operation at Hot Strip Mill 4 in Duisburg has resumed after a deflagration in the furnace area caused a fire on October 24, 2025. The furnaces and parts of the roof structure were damaged and have been extensively repaired or replaced.
Technical work and ramp-up
During the repair period, targeted technical optimizations and modernizations were implemented to improve plant availability and process stability. The associated continuous casting line had already resumed operation in mid‑December 2025. The current focus is on subsequent commissioning to transition from trial to regular operation.
Products and markets
Hot Strip Mill 4 is configured to produce hot‑rolled flat steels across a wide range of grades and dimensions, including higher‑strength, thinner premium steels with strict requirements for dimensional accuracy, surface quality and mechanical properties. These products feed downstream processing and serve automotive (including electric mobility), mechanical and plant engineering, construction and energy applications.
Source: thyssenkrupp
