Non-heat treated steel for induction hardening

A non-heat treated steel for induction hardening, consisting of, in mass %,

• C:
• 0.35 to 0.44%,
• Si:
• 0.01 to less than 0.30%,
• Mn:
• 0.80 to 1.50%,
• P:
• 0.030% or less,
• S:
• more than 0.010 to 0.095%,
• Cr:
• more than 0.10 to 0.30%,
• V:
• 0.050 to 0.200%,
• N:
• 0.0040 to 0.0200%,
• O:
• 0.0024% or less,
• Cu:
• 0.05% or less,
• Ni:
• 0.05% or less,
• Al:
• 0 to 0.040%,
• Ti:
• 0 to 0.020%,
• Nb:
• 0 to 0.020%,
• Pb:
• 0 to 0.30%,
• Ca:
• 0 to 0.0100%,
• Mo:
• 0 to 0.20%,
• fn1 defined by Formula (1) being 50.0 or less,
• fn2 defined by Formula (2) being 0.70 to 1.00,
• fn3 defined by Formula (3) being 1.30 or more, and
• the balance being Fe and impurities,
• wherein oxides are defined as inclusions containing oxygen in an amount of 20.0 mass % or more, and, among the oxides, Mn oxides are defined as inclusions containing oxygen in an amount of 20.0 mass % or more and Mn in an amount of 10.0 mass % or more, and a ratio of a total number of the Mn oxides with respect to a total number of the oxides is 10.0% or less;
• fn1=80C2+55C+13Si+4.8Mn+30P+30S+1.5Cr (1)
• fn2=C+(Si/10)+(Mn/5)-(5S/7)+(5Cr/22)+1.65V (2)
• fn3=−2C-Si+2.33Mn+0.26Cr+V-1.5Cu-1.5Ni (3)
• where a content in mass % of a corresponding element is substituted for each symbol of an element in Formula (1) to Formula (3).