METHOD OF HEAT TREATMENT OF UNALLOYED WHITE CAST IRON CASTINGS

摘要

metallurgy; heat treatment of unalloyed white cast iron casting; graphitizing annealing of unalloyed white cast iron castings; annealing chilled high-strength mottled cast iron and grey unalloyed cast iron. SUBSTANCE: proposed method includes graphitizing annealing which is performed in argon medium at content of nitrogen not exceeding 0.01 vol-%. EFFECT: reduced duration of heat treatment at first stage to 2 h; reduced annealing temperature to 900 C; reduced hardness of castings to 90-100 HB; improved workability. 1 dwg, 1 tbl