The casting-rolling mill (CRM) at ThyssenKrupp Steel Europe in Duisburg-Bruckhausen, Germany recently produced its 20 millionth tonne of hot strip.

It will be used to help people stay cool in the summer heat: Processed into hot-dip galvanized sheet, the 20 millionth ton was supplied as part of a 21t coil to ventilation group Lindab, who will use it to build air conditioning systems.

ThyssenKrupp started production on the CRM in 1999. It was regarded as a technological leap in flat steel production and at the time was the first line of its kind to be installed in an integrated iron and steel mill.

The 600M deutschmark line has proved to be an extremely lucrative investment: It produces hot strip faster, more energy efficiently and in excellent quality.

The CRM combines the normally separate production steps of casting and rolling in one continuous process. Material from the CRM has a more homogeneous microstructure than conventionally produced hot strip.

As a result, mechanical properties such as strength and elongation are also more consistent. The modern technology of the connected rolling mill provides for particularly close production tolerances and lower thicknesses on CRM hot strip.

Today the casting-rolling mill produces more than 50 steel grades for customers in the automotive, appliance, construction and electrical sectors among others.

These include grades which are regarded as difficult to produce due among other things to the higher casting speeds on CRMs.