Smelting process of S30408 austenitic stainless steel vertical continuous casting round billet

The invention belongs to the technical field of steelmaking, and particularly relates to a smelting process of an S30408 austenitic stainless steel vertical continuous casting round billet, a process route of induction furnace-argon oxygen furnace-external refining-continuous casting is adopted, an induction furnace charge is composed of more than 70% of S30408 return scrap, high-iron ferrochrome and a nickel plate, the argon oxygen furnace is used for decarburization until the carbon content is within 0.06%, ferrosilicon and aluminum are used for reduction deoxidation, and the smelting process is finished. The method comprises the following steps: adding lime and fluorite to carry out slagging, tapping into a steel ladle after proper components are obtained, carrying out refining, finely adjusting alloy components, carrying out continuous casting at a station of a double-flow vertical continuous casting machine, carrying out throwing at different speeds according to specifications and molten steel temperatur