Method for manufacturing cast iron casting with fining graphite and suspension part
AssigneesHyundai Motor Company, Kia Motors Corporation
InventorDong-Lim Seo
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Abstract
A method for manufacturing an austempered ductile cast iron and a product made from the austempered ductile cast iron manufactured by the method are disclosed. In the method for manufacturing an austempered ductile cast iron, spheroidizing agent and primary inoculant are added to a raw molten metal to create homogeneous spheroidal graphite creation in a deep part of a matrix and the raw molten metal to which the spheroidizing agent and the primary inoculant are added is injected into a mold to which secondary inoculant is locally applied, to micronize spheroidal graphite of a local structure coated with the secondary inoculant into fine graphite that is easy to machine, thereby enhancing workability as compared with a conventional austempered ductile cast iron.
Claims12
A method for manufacturing a cast iron product comprising microstructural graphite, the method comprising:
- adding spheroidizing agent and first inoculant into the molten metal in the furnace to perform spheroidization together with the primary inoculation for transforming the molten metal into inoculated molten metal in the furnace;
- injecting the inoculated molten metal after injecting the second inoculant into the mold, thereby performing secondary inoculation before the molten metal is solidified;
- and
- solidifying the inoculated molten metal in the mold to transform the inoculated molten metal into a cast iron product;
- and
- wherein the second inoculant comprises Fe—Si—Bi, Si of 0.3 wt % to 0.7 wt %, and Bi of 0.2 wt % to 0.5 wt % with respect to whole components of the molten metal, and remainder of Fe.
Dependencies are inferred from the claim text.