| 摘要 |
This rolled steel bar for a mechanical structure has a prescribed chemical composition, wherein: K1, determined according to K1 = C + Si/7 + Mn/5 + 1.54 × V, is 0.95 to 1.05; K2, determined according to K2 = 139 - 28.6 × Si +105 × Mn - 833 × S -13420 × N, is over 35; the content of Mn and S satisfies Mn/S ≥ 8.0; and the total decarburization depth of the surface layer is not more than 500 μm. |
