| 摘要 |
A boron-containing steel sheet which contains 0.20 to 0.45mass% of C, 0.05 to 0.8mass% of Si, 0.5 to 2.0mass% of Mn, 0.001 to 0.04mass% of P, 0.0001 to 0.006mass% of S, 0.005 to 0.10mass% of Al, 0.005 to 0.20mass% of Ti, 0.0010 to 0.01mass% of B, and 0.0001 to 0.01mass% of N, wherein the average concentration of solid-soluted B in a region lying from the surface to a depth of 100µm in the sheet-thickness direction is 10ppm or higher. |
