This invention discloses a method for controlling carbon increase in
molten steel based on
slag system modification, comprising the following steps: S1,
smelting endpoint control: controlling the carbon content,
phosphorus and
sulfur content, and tapping temperature of
molten steel at the endpoint of converter or electric furnace
smelting; S2, tapping alloying and initial carbon increase: adding a multi-element
nitride alloy and a first carbon increaser to the
ladle during tapping; S3,
argon blowing and stirring: performing a first stage of high-flow-rate
argon blowing and stirring; S4,
argon blowing
station fine-tuning: transporting
molten steel to the argon blowing
station for sampling and analysis, and supplementing with a second carbon increaser; S5, composition homogenization and soft blowing: sequentially performing a second stage of medium-flow-rate argon blowing and stirring, and a third stage of low-flow-rate soft blowing; wherein the
mass percentage of
manganese in the multi-element
nitride alloy is ≥5%. The
advantage of this invention is that by combining optimized
alloy composition, segmented carbon increase, and gradient stirring, it achieves precise control of a narrow composition window in molten steel.