HIGH-STRENGTH HIGH-TOUGHNESS STEEL PRODUCTS AND PRODUCTION METHOD THEREOF

摘要

A high-strength and high-toughness steel product having at least about 0.001% and less than about 0.030% by weight C, not more than about 0.60% by weight Si, from about 0.8 to 3.0% by weight Mn, from about 0.005 to 0.20% by weight Nb, from about 0.0003 to 0.0050% by weight B, and not more than about 0.005% by weight A1, wherein at least 90% of the product has a bainite structure. A method of making this steel product is subject to less stringent production controls because of the nature of the composition.