Boron alloying method for ladle refining

The invention provides a boron alloying method for ladle refining using boric acid (H3BO3) or borax (Na2B4O7?10 H2O) as a raw material for boron alloying of molten steel. The method comprises the following steps of (1) heating the boric acid or the borax with a heating temperature being higher than 400 DEG C and heating time being greater than 10 hours; (2) transferring a ladle to an LF for refinement, adding the boric acid or the borax when slag-making materials are added, heating the molten steel with a graphite electrode, and a bottom-blowing argon flow being 0.05-0.1 Nm3/h?t; (3) increasing the bottom-blowing argon flow after slag materials being melted and with bottom-blowing time being 3-10 min, heating the molten steel to a temperature of 1580-1600 DEG C with the graphite electrode, and moving out the ladle; and then adding ferrotitanium according to a requirement. The raw materials of the boron alloying are rich in resources and have a wide source. Adopting the boric acid or the borax to replace ferroboron for alloying, the method has a low alloying cost, is simple and reasonable in operation, and is energy-saving and environmental-friendly.