| 摘要 |
<p>A steel which has forgeability improved by diminishing the decrease in mechanical properties in the weakest-strength direction and which has satisfactory suitability for cutting. The steel, which is excellent in suitability for forging and cutting, is characterized by comprising 0.1 to 0.85 wt.% carbon, 0.01 to 1.5 wt.% silicon, 0.05 to 2.0 wt.% manganese, 0.003 to 0.2 wt.% phosphorus, 0.003 to 0.5 wt.% sulfur, 0.0003 to 0.01% zirconium, and iron and unavoidable impurities as the remainder, having an aluminum content of 0.01 wt.% or lower, a total oxygen content of 0.02 wt.% or lower, and a total nitrogen content of 0.02 wt.% or lower, and containing MnS having an average aspect ratio of 10 or lower and a maximum aspect ratio of 30 or lower.</p> |
