| 摘要 |
Provided is a strength member wherein, by reducing the mean dislocation density in an arbitrary cross-section, settling resistance and yield strength are substantially improved without reducing cost advantages or adding substantial process changes. By mass, said strength member contains 0.5-0.7% carbon, 1.0-2.0% silicon, 0.1-1.0% manganese, 0.1-1.0% chromium, up to 0.035% phosphorus, and up to 0.035% sulfur, with the remainder comprising iron and unavoidable impurities. By area, bainite constitutes at least 65% of this strength member, and the mean dislocation density in an arbitrary cross-section is no more than 2.0×1016 m-2. |
