Carburized steel part having excellent low cycle bending fatigue strength

A carburized steel part having excellent low cycle bending fatigue strength which is comprised of a steel material consisting of, by mass %,

• C:
• 0.1 to 0.6%,
• Si:
• 0.01 to 1.5%,
• Mn:
• 0.3 to 2.0%,
• P:
• 0.02% or less,
• S:
• 0.001 to 0.15%,
• N:
• 0.001 to 0.03%,
• Al:
• 0.001 to 0.06%,
• Ti:
• 0.01 to 0.2%,
• B:
• 0.0002 to 0.005%,
• Cr:
• 1.2 to 3.0%,
• Ca:
• 0.0002 to 0.005%,
• O:
• 0.005% or less and
• one or both of Nb:
• 0.01 to 0.2% and V:
• 0.03 to 0.2%, and
• a balance of substantially iron and unavoidable impurities, wherein the steel material which is carburized, quenched, and then tempered,
• wherein said carburized steel part has a surface hardness of HV550 to HV800, and a core hardness of HV400 to HV500.