Abstract: The manufacturing method of high-manganese spheroidal graphite cast iron with exhibiting low magnetism, and excellent wear resistance, castability, and machinability, and having a composition which consists of, 2.5 to 4.0 wt. % of C content, 1.5 to 6.0 wt. % of Si content, 7.0 to 18.0 wt. % of Mn content, and 0.015 to 0.1 wt. % of Mg content, and when the Mn content falls within the range of 7.0 to 10.0 wt. %, consists of 10.0 wt. % or smaller of Ni content, or when the Mn content falls within the range of 10.0 to 18.0 wt. %, consists of Ni content being in the range satisfies the following formula: [Mn wt. %>Ni wt. %], the method comprises heating the above cast iron to the temperature of 1073 to 1373K to decompose the carbides, and then quenching from 1073 to 1273K the resulting cast iron to form a metastable austenite matrix structure that contains no carbide or a reduced amount of carbides.

Abstract: The manufacturing method of high-manganese spheroidal graphite cast iron with exhibiting low magnetism, and excellent wear resistance, castability, and machinability, and having a composition which consists of, 2.5 to 4.0 wt. % of C content, 1.5 to 6.0 wt. % of Si content, 7.0 to 18.0 wt. % of Mn content, and 0.015 to 0.1 wt. % of Mg content, and when the Mn content falls within the range of 7.0 to 10.0 wt. %, consists of 10.0 wt. % or smaller of Ni content, or when the Mn content falls within the range of 10.0 to 18.0 wt. %, consists of Ni content being in the range satisfies the following formula: [Mn wt. %>Ni wt. %], the method comprises heating the above cast iron to the temperature of 1073 to 1373K to decompose the carbides, and then quenching from 1073 to 1273K the resulting cast iron to form a metastable austenite matrix structure that contains no carbide or a reduced amount of carbides.