| 摘要 |
<p>A method for producing a high toughness, high tensile strength steel plate comprises subjecting to a low temperature rolling a steel composition containing not more than 0.25% of carbon, not more than 0.5% of silicon, 0.5 to 2.0% of manganese, not more than 0.015% of sulfur, 0.005 to 0.1% of aluminum, not more than 0.025% of phosphorus, one or more of niobium, vanadium and titanium in an amount not less than 0.01%, and at least one rare earth metal (REM), such that REM/S is not less than 1.3 and optionally one or more of nickel, chromium and copper, with the balance being iron and unavoidable imputities; the steel shows low notch toughness transition temperature and high absorbed energy in the notch-impact test, and is suitable under as rolled condition for use as pipe lines in cold district.</p> |
