Steel for nitrocarburizing and nitrocarburized component, and methods of producing same

A component comprising a core part and a surface layer, wherein

• the core part comprises a chemical composition that consists of, in mass %,
• C:
• 0.01% or more and less than 0.20%,
• Si:
• 1.0% or less,
• Mn:
• 1.5% or more and 3.0% or less,
• P:
• 0.02% or less,
• S:
• 0.06% or less,
• Cr:
• 0.30% or more and 3.0% or less,
• Mo:
• 0.005% or more and 0.40% or less,
• V:
• 0.02% or more and 0.5% or less,
• Nb:
• 0.003% or more and 0.20% or less,
• Al:
• 0.010% or more and 2.0% or less,
• Ti:
• more than 0.005% and less than 0.025%,
• N:
• 0.0200% or less,
• Sb:
• 0.0005% or more and 0.02% or less, and
• optionally one or more selected from the group consisting of
• B:
• 0.0100% or less,
• Cu:
• 0.3% or less,
• Ni:
• 0.3% or less,
• W:
• 0.3% or less,
• Co:
• 0.3% or less,
• Hf:
• 0.2% or less,
• Pb:
• 0.2% or less,
• Bi:
• 0.2% or less,
• Zn:
• 0.2% or less, and
• Sn:
• 0.2% or less, and
• the balance consisting of Fe and incidental impurities, with the chemical composition satisfying either one of following relations:
• in a case where the C content is 0.01% or more and 0.10% or less,
• (S/32)/(Ti/48)+(N/14)/(Ti/48)≤13.0, wherein each of S, Ti and N represents respectively S content, Ti content and N content expressed as mass %, and
• in a case where the C content is more than 0.10% and less than 0.20%,
• 2(S/32)/(Ti/48)+3(N/14)/(Ti/48)≤35.0, wherein each of S, Ti and N represents respectively S content, Ti content and N content expressed as mass %,
• the core part comprises a steel microstructure that contains bainite phase in an area ratio of more than 50%, and
• the surface layer comprises a chemical composition with high nitrogen and carbon contents relative to the chemical composition of the core part.