Vacuum furnace production practice of ultra-low carbon steel
Vacuum furnace production of ultra-low carbon steel, the early stage of the process is the most difficult to control the rapid aluminium deoxidizing and alloying of decarburization and late. For vacuum furnace, on the premise of basic stable equipment performance, through optimizing decarburization process operation process, summarize utilization coefficient of carbon and oxygen reaction and the rate of the aluminium deoxidizing and alloying, figure out some empirical formula, greatly reducing the vacuum processing time, speed up the production rhythm, improves the product quality.
Vacuum furnace of ultra-low carbon steel production process, from the converter steel – steady oxygen measurement sampling – light processing measured again seven minutes to steady oxygen to 8 minutes of deep decarburization process, steady oxygen measurement sampling – aluminium deoxidizing and alloying – cycle after 3 minutes to steady oxygen measurement sampling, 5 minutes after the steel net cycle.
According to this process, difficult control mainly has two aspects, first, how to take off carbon to the lowest in 15 minutes; Second, according to 15 minutes after the decarburization of the residual oxygen content in liquid steel, aluminum one-time add in position, aluminum DNA can be ensured and the aluminum alloy and can guarantee. In this way, the smelting time can control between 25 to 30 minutes. Otherwise, the vacuum processing time was significantly longer. Smelting in the process of production of ultra-low carbon steel, as the extension of time, the contact between refractory material and steel liquid will lead to carbon steel back, in addition, the amount of ultra-low carbon steel because of the addition of aluminum is larger, a lot of Al2O3 inclusions produce, so the aluminum to join the sooner, the more conducive to Al2O3 inclusions floatation, the more conducive to the process after the operation and improve the quality of our products.