Method for producing boron steel by converter

The invention provides a method for producing boron steel in a converter, which is characterized in that argon subaeration is performed on a ladle in the whole process; a deoxidizer and alloys required by steel grades are begun to be added into the ladle for preliminary deoxidation and alloying under the condition of 1/4 tapping, and simultaneously a desulfurizer is added for desulfurization treatment; aluminum is added into the ladle in an argon blowing station for final deoxidation, and ferroboron is added into the ladle when the [O] is controlled to be between 0.0020 and 0.0040 percent; and the ferroboron is coated by an aluminum sheet and added into molten steel. The method has the advantages that: firstly, the method saves the refining procedure of an LF furnace and a vacuum furnace and has low production cost, short production procedure and high production efficiency; secondly, the pourability of the molten steel is good; thirdly, no requirement is put forward as for acid-soluble aluminum in the steel, so that the method solves the problems of pastiness of the molten steel, easy bonding of water gaps, reduction of the steel quality and the like caused by the increase of Al2O3 inclusion due to high acid-soluble aluminum; and fourthly, the recovery rate of boron can reach 60 to 75 percent and the wave range of the yield is small. Moreover, the method has good application prospect.