Mechanical component

Abstract

There is provided a high-strength steel mechanical component. A mechanical component is a mechanical component composed of a steel having a carbon content of more than or equal to 0.2 mass % and less than or equal to 0.8 mass %, and includes a quench-hardened layer formed in a surface layer of the mechanical component. In the quench-hardened layer, a grain size number of prior austenite crystal grains is No. 11 or higher. Moreover, the quench-hardened layer may have a Vickers hardness of more than or equal to 500 HV. In this case, prior austenite crystal grains in the quench-hardened layer become fine, thereby providing the mechanical component with high strength.

1 . A mechanical component composed of a steel having a carbon content of more than or equal to 0.2 mass % and less than or equal to 0.8 mass %, the mechanical component comprising a quench-hardened layer formed in a surface layer of the mechanical component,
 in the quench-hardened layer, a grain size number of prior austenite crystal grains being No. 11 or higher.   
     
     
         2 . The mechanical component according to  claim 1 , wherein the quench-hardened layer has a thickness of more than or equal to 4 mm. 
     
     
         3 . The mechanical component according to  claim 1 , wherein the quench-hardened layer has a Vickers hardness of more than or equal to 500 HV.