METHOD OF MODULAR CAST IRON'S TWO-STAGE TREATMENT

摘要

The solution concerns a method of the two-step treatment of ductile cast iron for thick-walled castings. The basic ductile cast iron flow is composed of 1.5 to 2.3 %weight of silicon, 2.7 to 3.6 % by weight of carbon, 0.01 to 0.06 % by weight of phosphorus, 0.03 to 0.08 % by weight of magnesium, and eventually 0.2 to 0.60 % by weight of copper, in the first step a magnesium foundry alloy is added and during the casting in the second step magnesium alloy containing 42 to 52 % by weight of silicon, 0.5 to 3 % by weight of magnesium, 0.5 to 1.3 % by weight of aluminium and 0.3 to 1.2 % by weight of calcium is added in the amount of 0.1 to 0.5 % by weight of the casting weight.