The application discloses a high-
nitrogen plastic mold steel, which comprises the following components: C with a
mass percentage of 0.28-0.33%, Si with a
mass percentage of 0.25-0.38%, Mn with a
mass percentage of 0.4-0.8%, Cr with a mass percentage of 14.5-15.5%, Mo with a mass percentage of 0.9-1%, N with a mass percentage of 0.095-0.115%, P with a mass percentage of less than or equal to 0.02%, S with a mass percentage of less than or equal to 0.003%, and O with a mass percentage of less than or equal to 0.0025%. The method for protecting
atmosphere electroslag remelting the high-
nitrogen plastic mold steel can ensure the
nitrogen content of the plastic mold steel and improve the comprehensive characteristics of the plastic mold steel, for example, the setting parameters of the
slag system and the
filling ratio can ensure that the crystallized steel
ingot is dense, the material is uniform, and non-metallic inclusions can be removed well; the N charging flow rate in the remelting process can keep the balance between the furnace
atmosphere and the N content in the
molten steel, and can ensure that the N content deviation of the whole steel
ingot is small and consistent with the
parent material before remelting.