NPO Laboratory of Special Steels and Alloys, a company of PJSC Kirovsky Zavod, based in St Petersburg, Russia, has placed an order for a one-strand Vertical Semi-Continuous Caster (VERSCON) with SMS Concast, a company of SMS group (www.sms-group.com). Instead of using the classical ingot casting solution for small niche production, NPO chose the innovative and yield-optimized VERSCON technology to produce special alloys and stainless steel for industries with extremely high requirements on the quality of the final product, as in the automotive, aircraft, tractor and engineering industries.
The one-strand VERSCON vertical semi-continuous caster for NPO will produce round and square section sizes ranging from 350 to 550 millimeters in lengths of up to eight meters. With an annual production of 31,000 tons, it will be designed to match the meltshop capacities, including an electric arc furnace, a ladle furnace and a VOD degasser. The machine will feature modern equipment such as a tundish heating system from IAS GmbH, a company of SMS group, to allow low superheating in the tundish for a stable casting process.
In addition, the hot-top treatment system, patented by SMS Concast, will compensate top shrinkage cavities, assuring maximum yield. “VERSCON combines the advantages of ingot casting and continuous casting at an affordable CAPEX. Further benefits over ingot casting include a cleaner work environment and lower operational costs.
Thanks to the high bloom quality, the blooms can be transferred directly to the forging or tertiary metallurgy facilities without any additional conditioning. For all these reasons, we have chosen the innovative VERSCON technology from SMS Concast, as it enables us to produce highly demanding steel grades in top quality and with maximum yield,” says A. Potanin, CEO of NPO.
In comparison to the conventional, curved continuous casting process, in ingot casting there are no restrictions in terms of steel grades, and bloom sizes and weights can be chosen more flexibly. However, for smaller production volumes below 200,000 tons per year, the VERSCON semi-continuous casting technology is a viable alternative to ingot casting. The driving idea behind the VERSCON design concept is to cast one or two ladles on one or more vertical strands into long blooms.
The process consists of two main steps: Firstly, a long bloom is cast by means of a conventional mold and oscillation table. As soon as the strand has reached its final length, the casting process stops and the strand is held in position until final solidification is achieved. Depending on the section size, it can take several hours for the bloom to reach final solidification. Finally, it is removed from the machine and cut to length; tertiary cooling facilities complete the process. Commissioning of the new plant is scheduled for the second half of 2021.