Patent ID: 10808304

Abstract:
A steel for induction hardening according to the present invention includes a chemical composition consisting of, in mass percent: C: 0.58 to 0.68%, Si: 0.70 to 1.40%, Mn: 0.20 to 1.40%, Al: 0.005 to 0.060%, N: 0.0020 to 0.0080%, and Ca: 0.0005 to 0.005%, with the balance being Fe and impurities, and satisfies Formulae (1) to (3). The steel microstructure is made up of ferrite and by area fraction, 85% or more of pearlite. In the steel, a ratio of a number of composite inclusions to a total number of Al2O3 inclusions and the composite inclusions that contain 2.0% or more of SiO2 and 2.0% or more of CaO is 20% or more. C+Si/7+Mn/5+Cr/9+Mo/2.5≤1.05  (1)C+Si/10+Mn/20+Cr/25≥0.70  (2)Cr/Si≤0.20  (3)