Alloy addition method for smelting chromium-containing alloy steel through converter

The invention provides an alloy addition method for smelting chromium-containing alloy steel through a converter. According to the method, the process of smelting low-chromium alloy steel comprises the steps of conducting double-slag smelting through the converter, controlling the steel tapping contents P and C and the steel tapping temperatures, adding ferrochromium into a large tank to conduct alloying out of the converter, conducting off-line or on-line roasting, and blowing argon after steel tapping; the process of smelting medium-chromium alloy steel comprises the steps of conducting duplex smelting through the converter, controlling the steel tapping contents P and C and the steel tapping temperatures, adding 20-60 kg of ferrochromium per ton of steel into the large tank to conduct alloying out of the converter, conducting off-line or on-line roasting, blowing argon after steel tapping, and supplementing a ladle furnace (LF) with 5-10 kg of ferrochromium per ton of steel; the process of smelting high-chromium alloy steel comprises the steps of conducting duplex smelting through the converter, controlling the steel tapping contents P and C before adding mixed alloy and the steel tapping temperatures, conducting alloying in the converter, adding ferrochromium and aluminum particle mixed alloy when half-steel is obtained after duplex smelting through the converter, conducting oxygen igniting and blowing, controlling lance position and oxygen pressure, additionally adding ferrochromium according to the steel tapping Cr content, blowing argon after steel tapping, and conducting RH vacuum decarburization. By means of the method, the chromium-containing alloy steel can be produced in the converter through the oxidization method, the alloy yield is high, and the production cost can be effectively lowered.