Abstract: The production of ultra-low carbon automobile plate DC04 steel by scrap management-EAF-RH vacuum treatmentslab continuous casting process was introduced. Aiming at the problem that C, N and residual elements were difficult to control in short-process smelting process, the reaction principle and production process were emphatically analyzed. The targeted process improvement schemes and technical measures were adopted from scrap management, EAF, vacuum refining to continuous casting, including establishing digital scrap management mode, optimizing EAF endpoint control and scrap preheating process, accurate control of RH vacuum degree and optimization of slag system, revising raw materials standards for continuous casting and optimizing process parameters.The mass fraction of carbon and nitrogen elements in steel was reduced to below 0.002 5 % and 0.003 0 % respectively, and the mass fraction of residual elements of molybdenum, nickel, copper and boron in steel were reduced to below 0.02 %, 0.05 %, 0.08 % and 0.000 6 % respectively, which met the standard requirements of DC04 steel for ultra-low carbon automobile plates and improved the product quality.

Key words: ultra-low carbon, EAF, automobile plate, decarbonization, nitrogen control, residual elements