Iron and Steel Division - Volume 185 - Iron and Steel Division - The Interaction of Liquid Steel with Ladle Refractories - Discussion

J. STEVENS*—The authors state that the contamination in the metal was due mostly to the ladle refractories. Did the contamination vary with different brands of refractories or different qualities in the ladle ? C. B. POST (authors' reply)—That would be expected. In our shop we have used a grade of firebrick which is fairly standard. We do use high refractory nozzles to combat this erosion and high refractory sleeves, but there is such a problem when you get a skull in a ladle you just cannot use these high refractory bricks; you rip out the whole ladle getting the skull cleaned up. The acid bricks form a glass, and you can pull the skull out when you do get them. I believe you might find variations among the different refractories depending on how much silicon is in the brick. This determines how much silica is going into the interface between the steel and the brick. Our brick is about 35 pet alumina and 65 pet silica. With a brick of 35 pet alumina in the slag patches new calculations would have to be made. R. PARDEE*—Where can you draw the line in determining the refractories as being a silica refractory ? C. B. POST—More silica than about 50 pet. I think perhaps that is generally the criterion. The brick we use is a good high grade fire brick. T. S. WASHBURN*--With reference to the higher silicon that is recommended as a result of this investigation, is it contemplated that the specified range would be raised to 0.40-0.60 pet silicon, or possibly 0.50-1.00 pet silicon? These higher silicon ranges would affect the physical properties of the steel and consequently there might be some complications with respect to educating the consumers to 'accept this revision of the conventional analysis. C. B. POST—It will take considerable work. Take AMS 6260 as an example. Ordinarily this specification calls for 60 or 75 manganese. Silicon has some