Steel for carburizing, carburized steel component, and method of producing the same

A steel for a carburizing comprising as a chemical composition, by mass %,

• C:
• 0.07% to 0.13%,
• Si:
• 0.0001% to 0.50%,
• Mn:
• 0.0001% to 0.80%,
• S:
• 0.0001% to 0.100%,
• Cr:
• more than 1.30% to 5.00%,
• B:
• 0.0005% to 0.0100%,
• Al:
• 0.0001% to 1.0%,
• Ti:
• 0.010% to 0.10%,
• N:
• limited to 0.0080% or less,
• P:
• limited to 0.050% or less,
• O:
• limited to 0.0030% or less, and
• a balance consisting of iron and unavoidable impurities, wherein:
• amounts expressed in mass % of each element in the chemical composition satisfy simultaneously a following Equation 1 as a hardness parameter, a following Equation 2 as a hardenability parameter, and a following Equation 3 as a TiC precipitation parameter;
• a shape is a bar or a wire rod in which a cross section perpendicular to a longitudinal direction is round;
• and
• when a distance from a periphery to a center of the cross section is defined as r in unit of mm, in a metallographic structure of a surface layer which is a portion from the periphery to r×0.01, a ferrite and a pearlite are limited, by area %, to 10% or less in total, and a balance includes at least one of martensite, bainite, tempered martensite, tempered bainite, and cementites,
• 0.10<C+0.194×Si+0.065×Mn+0.012×Cr+0.078×Al<0.235 (Equation 1)
• 7.5<(0.7×Si+1)×(5.1×Mn+1)×(2.16×Cr+1)<44 (Equation 2)
• 0.004<Ti—N×(48/14)<0.030 (Equation 3).