Low-nitrogen SWR82B steel smelting method

The invention discloses a low-nitrogen SWR82B steel smelting method. The method comprises the following steps: (1) during converter smelting, a top-bottom combined blowing converter adopts whole-process bottom argon blowing to blow SWR82B steel; (2) a low-nitrogen recarburizer is adopted for recarburization during a steel tapping deoxidation alloying process; (3) micro positive pressure operation is adopted during the refining process of an LF furnace; (4) full-protection casting is adopted during a continuous casting process: steel flow from a steel drum to a tundish is conveyed by a long protective casing and is sealed by blowing argon gas; the tundish adopts a special covering agent for SWR82B steel to cover molten steel; steel flow from the tundish to a crystallizer is conveyed by a long casing; the crystallizer adopts special casting powder for SWR82B steel. Through the method provided by the invention, the nitrogen content in an SWR82B coiled steel bar is reduced to below 40 ppm, the aging time of the SWR82B coiled steel bar is shortened, and the drawing and fracturing rate of the coiled steel bar is reduced. The method is suitable for SWR82B coiled steel bar manufacturers.