Production route – grain oriented silicon steel strip
The strip production route for high-permeable grain-oriented electrical steel starts with annealing and descaling of hot strip. This happens in a special annealing and pickling line. This is followed by cold rolling, primary recrystallization together with decarburizing, nitriding and magnesium oxide coating as well as secondary recrystallization for attaining the final orientation of the microstructure and the cleanliness of the material. Cold rolling normally takes place in a reversing cold mill. In the decarburizing and coating line also the nitriding step is included. Some process routes require an intermediate annealing line too.
For secondary recrystallization a special high-temperature batch annealing furnace is needed which anneals the material with temperatures up to 1,200 °C. The process is usually concluded by thermal flattening and final coating.