Hot forged non-heat treated steel for induction hardening

Abstract

A hot forged non-heat treated steel for induction hardening, comprising by mass percent, C: 0.35 to 0.45%, Si: 0.20 to 0.60%, Mn: 0.40 to 0.80%, S: 0.040 to 0.070%, Cr: 0.10 to 0.40%, Ti: 0.020 to 0.100%, Ca: 0.0005 to 0.0050%, B: 0.0005 to 0.0030%, 0: 0.0015 to 0.0050%, Mo: 0 to 0.05%, P: 0.025% or less, V: 0.03% or less, Al: 0.009% or less and N: 0.0100% or less, and the balance being Fe and impurities, with Fn1=C+(Si/10)+(Mn/5)+(5Cr/22)+1.65V−(5/7S)+1.51×(Ti−3.4N)≦0.63, Ca/O≦1.0, and 25.9×Fn1+27.5×(Ti−3.4N)−7.9≧5.7, has more excellence in the machinability than a conventional steel and also has fatigue strength equal to or more than that of a conventional steel, while using the steel product in a hot forged state as a starting material.

Dependencies are inferred from the claim text.