| 摘要 |
<p>PURPOSE: A steel with excellent crack propagation resistance property is provided to delay propagation even if the crack is generated by controlling internal organization and composition to proper range. CONSTITUTION: A steel with excellent crack propagation resistance property comprises less than 0.5% of C, less than 2.5% of Si, less than 3.0% of Mn, less than 0.03% of P, less than 0.02% of S, less than 0.1% of Al, remainder Fe, and impurities. The steel with excellent crack propagation resistance property has less than 15Mm of average diameter of crystal grain. The diameter is greater than 0.27(1/Mm) average of perimeter of the crystal grain greater than 20Mm divided by corresponding crystal grain area(Mm ^2).</p> |
