Thyssenkrupp is restarting hot rolling mill No. 4 in Duisburg

German firm Thyssenkrupp Steel is resuming production at its No. 4 hot rolling mill in Duisburg following extensive repairs. This is stated in a company press release.

The company announced the start of trial operations following a fire that occurred in October 2025.

Following the incident, Thyssenkrupp Steel carried out extensive repair and restoration work on the affected areas. During this period, targeted technical optimisation and modernisation were also carried out to improve future operational readiness and the stability of the production process. The associated continuous casting line resumed operations in mid-December 2025.

“The resumption of trial operation of hot rolling mill No. 4 is an important step in strengthening the stability, flexibility and reliability of our production network. Combined with the upgraded continuous casting line and the new, digitalised slab logistics, this restores one of the most modern production networks in the European steel industry,” said Marco Richrath, Chief Operating Officer of Thyssenkrupp Steel.

Hot rolling mill No. 4 is a key element of the comprehensive modernisation and optimisation of Thyssenkrupp Steel’s production network. It is designed to produce hot-rolled flat products in a wide range of grades and dimensions. In addition to standard steels, the range includes high-strength and thin premium steels with stringent requirements for dimensional accuracy, surface quality and mechanical properties. These products serve as raw materials for further processing and are used, in particular, in the automotive industry, as well as in mechanical engineering, instrument manufacturing, construction and the energy sector.

It should be noted that in June last year, Thyssenkrupp Steel commissioned a new continuous casting machine No. 4 (SGA 4) at its plant in Duisburg. As mentioned, this was the largest single investment project in recent decades.