ISP-ESP Production Process
Arvedi process technology for coils is based on casting thin slabs rolled in-line and is protected by numerous patents, covering the most important industrialised countries, regarding both the technology as a whole and the single plant components.
The ISP production line transforms steel—produced in an electric arc furnace or a converter—in a single, extremely compact cycle, enabling the production of thin gauges and dimensional characteristics that were difficult to achieve with many of the available technologies. The direct transformation of the liquid steel is obtained in only 180 metres and 15 minutes through in-line casting and rolling, exploiting the energy content of the liquid steel and its high plasticity at high temperatures. With the ESP line, the process from liquid steel to coil is completed in 180 meters and 5 minutes.
CASTING AND ROLLING PHASE
The liquid steel is cast into a thin slab through the “mould system”, patented by Arvedi, in order to obtain the best quality characteristics with a high level of production reliability. The thin slab leaving the mould is reduced in thickness while the core is still liquid and is rolled directly at high temperatures to obtain a high precision intermediate bar with a homogeneous structure. Directly connecting casting and rolling is a fundamental innovation and the key point of the new process technology.
HEATING PHASE
The intermediate bar, heated in the induction furnace for ISP is collected in the Cremona furnace, which is specifically fitted with a mandrel in order to coil bars in gauges below 18 mm, and make the temperature homogeneous, while for ESP it is directly charged into the finishing mill.
FINISHING ROLLING PHASE
The pre-rolled bar is fed directly, following descaling, into the finishing rolling mill, carrying out casting and rolling in a fully continuous process. It is reduced to its final thickness by the finishing mill, which operates at constant speed and temperature to achieve features required by the product. The strip is cooled on the roller table to impart the desired mechanical and structural properties to the steel and is immediately wound onto the coiler.
Thanks to these production technologies, originally developed within the Arvedi Group, the product has uniform qualitative characteristics, and the process configuration has been designed to optimize energy use across the different production stages.
