| 摘要 |
PROBLEM TO BE SOLVED: To provide a carbonitriding component that ensures excellent surface fatigue strength even when hydrogen embrittlement peeling occurs.SOLUTION: A carbonitriding component contains, by mass%, C:0.30 to 1.30%, Si:0.05 to 0.35%, Mn:0.40 to 1.50%, P:0.030% or less, S:0.030% or less, Cr:1.50 to 3.00%, Al:0.050% or less, O:0.0015% or less, N:0.025% or less, Mn+Cr:2.50 to 4.00% and the balance Fe with inevitable impurities and has a surface layer C concentration after a temper treatment of 0.80 to 1.50 mass%, a surface layer N concentration of 0.10 to 1.00 mass% and a surface hardness of HRC 58 to 64, a percentage of the number of Cr nitrides and Mn nitrides having a particle diameter of less than 300 nm to all nitrides dispersed with dispersion over surface layer of 70% or more, the number of the Cr nitrides and Mn nitrides of 10/mmor more, and a surface layer compressive residual stress of 600 MPa or more. |
