Patent ID: 10793937

Abstract:
A steel for induction hardening according to an aspect includes, as a chemical composition, predetermined amounts of alloy elements and a remainder including Fe and impurities, in which Al×N is 0.000330 to 0.000825, Mn/S is 4.6 to 14.0, a machinability index M is 15.5 to 25.65, an area fraction of AlN having an equivalent circle diameter of more than 200 nm at a ¼ position of a diameter of the steel is 20% or less of an area fraction of all AlN having an equivalent circle diameter of 40 nm or more, and a number density of Mn sulfide-based inclusions having a maximum diameter of 0.3 μm or more and 10 μm or less at the ¼ position of the diameter is 100 pieces/mm2 or more and 2500 pieces/mm2 or less.