Low Si-Mg ratio and low RE-Mg nodularizer

Abstract

The invention provides a low Si-Mg ratio and low RE-Mg nodularizer. The nodularizer comprises the following components by mass percent: 5 to 10 percent of Mg, 20 to 30 percent of Si, 0 to 2 percent of Ca, 0 to 0.5 percent of Al, 0 to 0.2 percent of Bi, 0 to 0.1 percent of Ba, 0 to 0.1 percent of Zr, less than 0.1 percent of Ce, less than 0.1 percent of La and Fe in balancing amount. The nodularizer provided by the invention has the advantages that the Si content and the RE content in the nodularizer are considerably reduced on the premise that smooth iron liquid nodulizing is guaranteed, so that not only the range of control of the Si content of original iron liquid is widened, but also beneficial technological conditions are created for enhancing modification, and the carbonide of thin-walled parts and the fragmental graphite of thick-walled parts can also be effectively eliminated; the nodulizing effect is excellent; and the nodularizer is especially suitable for production of high-quality high-ductility ductile iron castings and high-Ni austenite ductile iron castings.

Description

technical field [0001] The invention belongs to the technical field of material processing, and relates to a low-rare-earth magnesium nodulizer suitable for the production of high-toughness ductile iron and high-nickel ductile iron, in particular to a low-Si nodulizer suitable for the production of high-toughness ductile iron and high-nickel ductile iron / Mg ratio, low rare earth magnesium nodulizer. Background technique [0002] The spheroidizing process is a key technical link in the production of ductile iron castings. So far, rare earth magnesium nodularizers have played an irreplaceable role in the production of various grades of ductile iron. However, the currently used nodulizers, regardless of whether the Mg content is high or low, contain Si content as high as 40%-46%. The high silicon content makes the amount of silicon increased in the process of spheroidizing molten iron, and the average amount of silicon increased is as high as 0.6%. This not only puts pressu...

AI Technical Summary

Problems solved by technology

And in existing nodulizer, the mass ratio of Si and Mg (W Si / W Mg ) as high as (10-15): 1, the Si content is generally high, and the rare earth RE content is high, more than 0.3%, not only is not conducive to the control of the furnace, but also thick and large section ductile iron and high nickel ductile iron are prone to fragmentation Graphite, and increase the whitening tendency of thin-walled parts

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