Composition and method for producing an alloy steel and a product therefrom for structural applications
AssigneeBethlehem Steel Corporation
InventorsRichard L. Bodnar, Yulin Shen
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Abstract
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.
Claims8
An alloy steel plate having a plate composition consisting of alloying elements of carbon, manganese, titanium, niobium, vanadium and nitrogen, elements of phosphorus, copper, nickel, molybdenum, chromium and sulfur, and aluminum as a killing element in amounts, in weight percent, as follows:
- carbon between about 0.06 and less than 0.14%;
- manganese between 1.00 and 2.00%;
- silicon up to 0.04%;
- niobium between 0.03 and 0.05%;
- titanium between 0.006 and 0.02%;
- vanadium between 0.05 and 0.10%;
- nitrogen up to 0.012%;
- aluminum between 0.005 and 0.08%;
- phosphorus up to 0.03%;
- sulfur up to 0.02%;
- about 0.02% copper, about 0.03% nickel, about 0.01 molybdenum and about 0.04% chromium;
- and
- the titanium to nitrogen weight ratio is less than 3.4 to 1;
- and
- wherein the balance of the composition is iron and incidental impurities, the plate having a minimum of 450 MPa of yield strength and a minimum of 550 MPa of tensile strength.
Dependencies are inferred from the claim text.