PROCESS FOR MELTING ULTRA-LOW SULFUR AND LOW NITROGEN STEEL

To provide a process for melting an extremely low sulfur and nitrogen steel having a sulfur concentration of 5 ppm or less and a nitrogen concentration of 30 ppm or less.SOLUTION: The melting process for extremely low sulfur and low nitrogen steel includes a ladle refining process for performing desulfurization treatment by using a ladle refining furnace 5. The aluminum concentration in molten steel 2 is set to 0.020 mass% or more and 0.080 mass% or less at the start of refining treatment of the ladle refining process, and the ladle refining process is carried out by using the molten steel 2.SELECTED DRAWING: Figure 1 【課題】溶鋼の硫黄濃度を５ｐｐｍ以下、かつ窒素濃度を３０ｐｐｍ以下とする極低硫低窒素鋼の溶製方法を提供すること。【解決手段】取鍋精錬炉５を用いて脱硫処理を行う取鍋精錬工程を含む極低硫低窒素鋼の溶製方法であって、取鍋精錬工程の精錬処理開始時における、溶鋼２のアルミニウム濃度を０．０２０ｍａｓｓ％以上０．０８０ｍａｓｓ％以下とし、溶鋼２を用いて取鍋精錬工程を行う。【選択図】図１