Fpecial steel materials are melted in EBT electric arc furnace, refined in LF ladle, treated with VD vacuum degassing, and cast in sealed protection. They can produce high-purity steel. The fpecial steel materials have uniform composition and dense structure. The product performance is stable and far exceeds the industry's use requirements. The weight of fpecial steel materials is from 1.8 tons/piece to 65 tons/piece, mainly square ingots and plum blossom ingots (8 sides and 16 sides). For