| 摘要 |
<p>PURPOSE: To stably produce an ultralow sulfur steel by regulating a ladle slag compsn. in which, by mass%, Al2 O3 , MgO and CaO/SiO2 are specified. CONSTITUTION: The componental compsn. of a steel to be produced is composed of, by mass, <=0.20% C, <=0.005% Al and <=0.001% S, and the balance substantial Fe. In the production of the steel, a ladle slag compsn. of, by mass, Al2 O3 <=20%, MgO=5 to 15% and (CaO/SiO2 )=2.5 to 4.0 is regulated. In accordance with the increase in the concn. of Al2 O3 , the concn. of Al increases, and the more the basicity is made high, the more it increases. It is needed to regulate the concn. of Al2 O3 to <=20 mass%. Thus, the low carbon steel in which the content of S is limited can be produced without nearly using an Al alloy as a deoxidizer.</p> |
