The invention relates to a
smelting method for reducing
nitrogen increase in
molten steel in a converter process. The
smelting method comprises the following steps: limiting the
nitrogen content and size of a waste steel
raw material, changing bottom
argon blowing in the early stage of a converter into
nitrogen-
argon combined blowing, increasing the gas flow, adopting bottom pure
argon blowing in the middle and later stages of
smelting, and increasing the bottom blowing gas flow; the smelting final temperature is smaller than or equal to 1630 DEG C, an
oxygen lance is switched into argon, and argon is blown into the converter for 10-30 s; in the tapping process, 1.0 Kg / t to 1.2 Kg / t of
calcium carbide is added to the bottom of a steel
ladle in advance before tapping, 0.5 Kg / t to 1.0 Kg / t of
calcium carbide is thrown in a steel flow
impact area in the tapping process, CO generated by
calcium carbide deoxidation is used for forming an air curtain,
molten steel is isolated from air, and
nitrogen absorption of the
molten steel is reduced; the content of [O] in the molten steel in the tapping process is controlled to be (200-400) * 10 <-4 >%; bottom argon blowing of the steel
ladle is started 20 seconds before tapping, air in the steel
ladle is emptied, argon is stopped immediately after tapping is finished from 20 seconds before tapping to the end of tapping, and the steel ladle is covered for heat preservation to prevent molten steel from being exposed to increase nitrogen; the method is simple and clear in technological process, high in
operability and easy to control.