NON-THERMAL REFINED NITROCARBURIZED COMPONENT

1 . A non-thermal refined nitrocarburized component, comprising a steel material of a base metal, the steel material having a chemical composition comprising: by mass %,

C: 0.35 to 0.50%;

Si: 0.10 to 0.35%;

Mn: 2.3 to 2.8%;

S: 0.01% or less;

N: 0.0030 to 0.0250%;

Cu: 0 to 1.0%;

Mo: 0 to 0.3%;

Ni: 0 to 0.5%;

Ti: 0 to 0.020%; and

the balance: Fe and impurities, wherein

Fn1 shown by the below described Formula [1] satisfies 3.10≦Fn1≦6.00, and

the impurities include P: 0.08% or less; Al: 0.05% or less; and Cr: less than 0.20%, and wherein

at a stress concentrated region,

an HV hardness at a position of 0.05 mm from a surface is 410 to 480,

an HV hardness at a position of 1.0 mm from the surface is 200 or more,

a compound-layer depth is 5 μm or less, and

a metal micro-structure of the base metal is a bainite micro-structure:

Fn 1=(0.316 C+0.122)×(0.7 Si+1)×(5.1 Mn−1.12)×(0.364 Ni+1)×(2.16 Cr+1)×(3 Mo+1)   [1],

where an symbol of an element in Formula [1] indicates a content of the element in steel in mass %.

2 . The non-thermal refined nitrocarburized component according to claim 1 , wherein

the chemical composition of the steel material of the base metal contains, in mass %, one or more types of elements selected from

Cu: 0.05 to 1.0%, and

Mo: 0.05 to 0.3%.

3 . The non-thermal refined nitrocarburized component according to claim 1 , wherein

the chemical composition of the steel material of the base metal contains, in mass %, one or more types of elements selected from

Ni: 0.05 to 0.5%, and

Ti: 0.005 to 0.020%.

4 . The non-thermal refined nitrocarburized component according to claim 2 , wherein

the chemical composition of the steel material of the base metal contains, in mass %, one or more types of elements selected from

Ni: 0.05 to 0.5%, and

Ti: 0.005 to 0.020%.