Patent ID: 10801091

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%, P: less than 0.020%, S: less than 0.020%, Al: 0.005 to 0.060%, N: 0.0020 to 0.0080%, O: 0.0015% or less, V: 0.01 to 0.25%, B: 0.0003 to 0.0040%, Ti: 0.010 to 0.050%, 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 pearlite. A ratio of a number of composite inclusions 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)