ON THE SIDE-BLOWN BABY-BESSEMER PROCESS IN U.S.S.R. AND CHINESE COMMUNIST REGION

Abstract

Side-blown baby-bessemer converters are employed in foundries for the production of steel castings, in U.S.S.R. recently, however, a large number of this type of converters are also used for the production of steel ingots under a new name of "Soviet Union's Process." And also, they assert that steel made by the side-blown converters have lower gas content and higher resistance to the low-temperature shortness than the others made by the open hearth furnace. The distinctive point of this new process is to use the over-heated low-Si molten pig iron (0.3-0.5% Si, 1400-1450°C) in the converter. Therefore, it seems to be nearly identical with the old Swedish process, but they maintain that it is their own process.
Normally, in the baby-bessemer process, or in the high-or medium-Si process, they refine hematite pig iron, which is usually melted in usual cupolas. In works producing steel ingots by this new process, however, the cupolas are of a special design and the charge employed contains high percentages of steel scrap (90-95%), which is partially recarburized before blowing in the converter.
From the results of several practical studies on the high Si Process (>1.6% Si), the medium Si process (1.1-1.6% Si), the low-Si process (<1.0% Si) and this new process by a 1.5t converter in each, merits of this new process were pointed out as follows;
a) The shortening of the blowing time.
b) The lessening of the blowing-loss of molten metal.
c) The increasing of the steel scrap in the raw material of cupola.
In the Chinese communist region, lately, in some works this type of converters are also used for the production of steel ingots, and they are blowing the comparatively lower Si molten pig iron (0.8-1.2% Si, 1300-1350°C) in the converter. It may be said that, from the great demand of steels in that region, this simple process will be developed more and more in future.