High-nodularity nodulizer for nodular cast iron

Abstract

The invention discloses a high-nodularity nodulizer for nodular cast iron. The nodulizer is prepared from the following components in percentage by weight: 16% of Mg and Si, 3.0% of Re, 2.1% of Ca, 2.0% of Ba, 0.05% of Bi, 0.09% of Ti, 0.3% of Al, 1.0% of rare earth and Fe in balancing amount. The nodulizer prepared according to the invention adopts rare earth made from yttria, gadolinium oxide, holmium oxide and cerium oxide, so that the nodulizer is greatly enhanced in molten iron purification capacity, nodulizing capacity, nodulizing degeneration resistance and graphite distortion resistance, has a little chilling tendency, can refine a matrix structure, can prevent a resulfurization phenomenon, has high boiling point, can inhibit interference of anti-nodulizing elements, can improve the impact toughness of the nodular cast iron, can also improve the nodularity and the quality of a casting and has the characteristics of energy saving and pollution prevention; the nodulizer can effectively inhibit a nodulizing degeneration phenomenon of the nodular cast iron and meanwhile can accurately control the nodulizing reaction time; and owing to a synergistic effect of the added elements, the strength, hardness and heat resistance of the alloy can be effectively improved, and the nodularity can be greatly improved.

Description

technical field [0001] The invention relates to the field of molding sand production, in particular to a nodularizing agent for ductile iron with a high nodularization rate. Background technique [0002] The nodulizers currently produced and sold on the market are generally Re3Mg7-9 or Re5Mg7-9. Rare earth and magnesium content is high. There are the following problems: the production cost of the nodularizing agent is high; the poor nodularization makes the mechanical properties drop sharply, and the corresponding indicators cannot be reached. The important reason is that [0003] The residual amount of magnesium and rare earth is insufficient; during the spheroidizing treatment, the molten iron boils violently, accompanied by strong light and magnesium vapor safety hazards, which are very irritating to human skin and eyes, and at the same time, the temperature drops greatly, which will cause pores to appear in the casting , cold insulation, insufficient pouring and other ...

AI Technical Summary

Problems solved by technology

There are the following problems: the production cost of the nodularizing agent is high; the poor nodularization makes the mechanical properties drop sharply, and the corresponding indicators cannot be reached. The important reason is that

[0003] The residual amount of magnesium and rare earth is insufficient; during the spheroidizing treatment, the molten iron boils violently, accompanied by strong light and magnesium vapor safety hazards, which are very irritating to human skin and eyes, and at the same time, the temperature drops greatly, which will cause pores to appear in the casting , cold insulation, insufficient pouring and other defects; the absorption rate of molten iron to magnesium decreases, and the absorption rate of molten iron to magnesium generally reaches 70% when the absorption rate of molten iron is 4-6%. With the increase of magnesium, the absorption rate of molten iron to magnesium begins to decline, reaching At 8%, the absorption rate is only 50%, and at 9%, it is only 45%