| 摘要 |
<p>Disclosed is a steel component that has temper softening resistance at 300°C, and that is characterized by (a) the amount of Si contained in the steel being at least 0.7%, (b) a carburizing process being conducted that causes the amount of C contained in a carburized layer to be a hypereutectoid quantity of contained C that is 0.9-1.1%, (c) not causing carbides (pro-eutectoid cementite or spherical carbides) having an outer diameter of at least 0.1 µm to be present after the carburizing process, and (d) causing the amount of residual austenite after carburizing, quenching, and tempering to be less than 30%. The essential point is a steel component of which the combined total of contained Mn and Cr is no greater than 2.5% in a steel having a predetermined composition and of which the surface has been carburized, quenched, and tempered, wherein: the amount of contained C at a depth of 50 µm from the surface is 0.9-1.1%; pro-eutectoid cementite and spherical carbides having an average size of at least 0.1 µm are either not contained, or even when contained the area ratio thereof is less than 1%; residual austenite is not contained, or even when contained the area ratio thereof is less than 30%; and the temper softening resistance is excellent.</p> |
