An ultra-low-temperature-resistant nodular cast iron and a production process thereof

Abstract

This invention relates to the field of metallic materials and discloses a low-temperature resistant ductile iron and its production process. The ductile iron contains C, Si, low Mn, and additives composed of nano-TiO2, MgO, and CeO2. The process steps are as follows: premixing the additives with iron powder by ball milling; spheroidizing using a spheroidizing method after melting, combined with three-stage composite inoculation; and finally, two-stage ferritic annealing. Through the heterogeneous nucleation and grain boundary pinning effect of nanoparticles, this invention achieves simultaneous refinement of graphite spheroids and matrix grains under nickel-free conditions, improving impact energy, enhancing the low-temperature performance of the material, and reducing production costs.

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