| 摘要 |
<p>This invention relates to an ultra-high-strength steel bar and to a method of manufacturing the same., in which the steel bar includes C: 0.05 to 0.45 wt%, Si: 0.10 to 0.35 wt%, Mn: 0.1 to 0.85 wt%, Cr: 0.6 to 1.20 wt%, and Mo: 0.05 to 0.35 wt%, with the remainder being Fe, wherein a martensite structure is formed at a surface layer and a fine ferrite structure is formed at a center layer.</p> |
