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US 4,065,331 AGranted
Rolled low carbon niobium steel
AssigneeAlan Wood Steel Company
InventorFrederick J. Semel
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AssigneeAlan Wood Steel Company
InventorFrederick J. Semel
Estimating the term…
This is a process and product in which excellent properties are achieved with a relatively low alloy steel and normal rolling with a steel having the following composition in addition to iron and impurities, in percentages by weight: ______________________________________ Carbon .05 to .12 Manganese .25 to .90 Silicon .15 to .50 Nickel .15 to .50 Copper .15 to .50 Aluminum .02 to .110 Niobium (Columbium) .07 to .140 Nitrogen .007 to .015 Phosphorus .010 maximum Sulfur .025 maximum. ______________________________________
A steel in the as-rolled condition as a result of normal rolling practice having a lower yield point of at least 42.0 kilograms per square millimeter at room temperature, and a 2.8 kilogram meter Charpy V-notch transition temperature of no greater than -50.degree. C, having a composition consisting essentially of the following, expressed in percentages by weight:
A steel in the as-rolled condition using normal rolling procedure and made up mainly of iron and consisting essentially also of the following in percentages by weight:
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Ferrous alloys, e.g. steel alloys: containing copper
Ferrous alloys, e.g. steel alloys: containing tungsten, tantalum, molybdenum, vanadium, or niobium
Alloys
Term ended 27 Dec 1994 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
This invention relates to a special low carbon niobium steel and process.
I understand that J. M. Gray of the Molybdenum Corporation of America, in tests whose public report, if any, I do not know, has shown that it is possible to achieve an excellent combination of high strength and low temperature impact resistance in as-rolled heavy gauge plate using normal rolling and finishing conditions with steel of the following composition: ##EQU1## For example, 1/2-inch gauge plates finish rolled at 1800.degree. F (1000.degree. C) follows:
______________________________________ 40 ft-bl (5.6 Kgm) Yield Stg. Tensile Stg. Transition Temp. Psi (kg/mm.sup.2) Psi (kg/mm.sup.2) .degree. F (.degree. C) ______________________________________ 65,000 to 75,000 75,000 to 95,000 -60 to -150 (46.0 to 53.0) (53.0 to 67.0) (-50 to -100) ______________________________________
To test these indications, two platemill ingots, A and B, were modified by mold additions to a heat of the regular A.W. 0440 (Alan Wood 0440) grade of steel. Their compositions are shown below. Shown also is the composition of steel C corresponding to an unmodified platemill ingot of the regular 0440 grade but from an earlier heat than that used in the manufacture of steels A and B. The compositions are in percentages by weight.
__________________________________________________________________________ Steel C Mn P S Si Ni Cr Cu Mo Al Nb V N __________________________________________________________________________ A .11 .91 .007 .013 .26 .02 .02 .09 .004 .107 .085 nil .0051 B .09 .85 .006 .013 .49 .23 .02 :29 .004 .100 .120 nil .0080 C .08 .73 .009 .020 .25 .03 .03 .07 .005 .055 .055 nil .0056 __________________________________________________________________________
Steel A and, for that matter, Steel B each have a higher manganese content than was specified in the desired composition. This, of course, is a consequence of having used the 0440 grade as the base steel.