| 摘要 |
<p>The invention provides a carbon steel sheet including C: 0.20% to 0.45% by mass, Si: 0.05% to 0.8% by mass, Mn: 0.85% to 2.0% by mass, P: 0.001% to 0.04% by mass, S: 0.0001% to 0.006% by mass, Al: 0.01% to 0.1% by mass, Ti: 0.005% to 0.3% by mass, B: 0.0005% to 0.01% by mass and N: 0.001% to 0.01% by mass, in which a K value that can be obtained from 3C+Mn+0.5Si is greater than or equal to 2.0; surface hardness is less than or equal to 77 on the Rockwell B Scale; and the average content of N in a zone from the surface to a depth of 100μm is less than or equal to 100 ppm. This carbon steel sheet is configured to be carburized in a carburization atmosphere with a carbon potential of 0.6 or less.</p> |
