Bethlehem Steel Corporation

Other

Yulin Shen

Richard L Bodnar

Wung-Yong Choo

Jang-Yong Yoo

A method of making a high strength low-alloy steel includes the steps of casting an alloy steel into a cast form, hot rolling the cast form into a partially rolled form, and control rolling the partially rolled form to a rolled product. The controlled rolling is discontinued at a discontinue rolling temperature and is then acceleratedly cooled to a finish cooling temperature. The alloy steel uses a low silicon, carbon niobium, vanadium, titanium-containing steel composition. Silicon is less than 0.04% by weight, vanadium is between 0.05 and 0.10% by weight, niobium is between 0.06 and 0.14% by weight, titanium is between 0.006 and 0.02% by weight, and carbon is between 0.06 and 0.14% by weight. The controlled chemistry, controlled rolling, and accelerated cooling allows the discontinue rolling temperature to be high, thereby improving rolling productivity. The low-carbon alloy chemistry results in improvements in castability, formability, and weldability.

Composition and method for producing an alloy steel and a product therefrom for structural applications

A method of making a weathering grade steel plate includes the steps of establishing a minimum yield strength:plate thickness target from one of 50 KSI:up to 4&Prime;, 65 KSI:up to 1.5&Prime;, and 70 KSI:up to 1.25&Prime;. A modified weathering grade alloy composition is cast into a slab employing effective levels of manganese, carbon, niobium, vanadium, nitrogen, and titanium. The cast slab is heated and rough rolled to an intermediate gauge plate. The intermediate gauge plate is controlled rolled and subjected to one of air cooling or accelerated cooling depending on the minimum yield strength and thickness target. With the controlled alloy chemistry, rolling and cooling, the final gauge plate exhibits discontinuous yielding and can be used for applications requiring a 70 KSI minimum yield strength in plate thicknesses up to 1.25&Prime;, a 65 KSI minimum yield strength in plate thickness up to 1.50&Prime; and a 50 KSI minimum yield strength for plates as thick as 4&Prime;.

Method of making an as-rolled multi-purpose weathering steel plate and product therefrom

A high strength low-alloy steel is subjected to a controlled rolling and accelerated cooling process to obtain minimum physical properties while achieving improved mill productivity. The alloy chemistry utilizes a low silicon, carbon, niobium, vanadium, titanium-containing steel composition which is hot worked and accelerated cooled under controlled conditions. The chemistry, controlled rolling and accelerated cooling allows for significant increase in the finishing rolling temperature thereby permitting high rolling output. The alloy chemistry includes a low-carbon grade which also has improved castability, formability and weldability.

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Bethlehem, PA, United States of America

Yulin Shen