Turkish steel producer Çolakoğlu’s vacuum oxygen decarburization (VOD) plant, located in Dilovası about 60 kilometers to the south-east of Istanbul, achieved a heat size of 298.2 tons. This same plant also obtained a carbon content of 5 parts per million (ppm) after decarburization, making that two world records for Çolakoğlu.
Leading expertise in stainless steelmaking
“A pioneer in the Turkish steel industry, Çolakoğlu dares to try new things. Our achievement at the VOD plant is the latest proof of this determination. While giving credit to my colleagues who have carried the flag and achieved extraordinary results, I thank Primetals Technologies for their good collaboration and support. Together we create value by recycling stainless scrap, thus creating stainless steel for the Turkish industry—and we will contribute to reducing Turkey’s trade deficit by replacing imports,” says Uğur Dalbeler, CEO of Çolakoğlu.
One of the Largest in the World
To reach record-breaking results like the ones at the VOD plant in Dilovası, the process parameters for the furnace allow tapping at high temperatures and avoid clogging issues, panel leakage, and refractory problems. The VOD-system in Dilovası is designed for enormous heat sizes, whereas a typical VOD-plant produces heat sizes between 60 to 150 tons.
The electric steel plant in Dilovası predominantly produces slabs for hot-rolling and billets that eventually become reinforcing steel bars and steel rock bolts. In late 2020, the Dilovası plant was modernized and upgraded, becoming a VOD plant, one of the largest in the world.
Extra-low carbon stainless steel grades
The VOD-system is a tank degassing unit equipped with an oxygen blowing lance, a vacuum pump regulation for oxygen blowing conditions, and other necessary components such as gas cooling, dust filtering, and CO-burning systems. Furthermore, this plant uses advanced process models to achieve accurate end process parameters such as end chemical analysis and liquid steel temperature. The additional oxygen supply can be used for producing extra-low carbon stainless steel grades (forced decarburization) or for chemical heating of the melt in conjunction with aluminum/silicon additions (the VD-OB process). These factors allow Çolakoğlu to produce stainless steel with extremely low amounts of carbon.