Method for producing extremely low sulfur chromium-containing molten steel

摘要

PPROBLEM TO BE SOLVED: To provide a method for producing a molten steel containing chromium and extremely little sulfur and aluminum without using fluorite containing fluorine, which is conventionally used but is harmful to the environment. PSOLUTION: The method for producing the molten steel containing chromium comprises; the primary refining step of smelting molten crude steel by adding a chromium source to a preliminarily treated molten pig iron and by blowing oxygen into it; and the secondary refining step of producing the molten steel by adjusting components contained in the molten crude steel. In the above secondary refining step, the method includes adjusting a total amount of sulfur in the molten crude steel and a slag that covers the molten crude steel so as not to exceed 1.5 times the target amount of sulfur in the molten steel, and then the composition of the slag so as to contain CaO/SiOSB2/SBof 1.5 to 2.2 (both inclusive) and 12 mass% to 18 mass% (inclusive) AlSB2/SBOSB3/SB. PCOPYRIGHT: (C)2007,JPO&INPIT