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Publication numberUS2444422 A
Publication typeGrant
Publication dateJul 6, 1948
Filing dateSep 7, 1942
Priority dateSep 7, 1942
Publication numberUS 2444422 A, US 2444422A, US-A-2444422, US2444422 A, US2444422A
InventorsVictor H Bradford
Original AssigneeSpecialties Dev Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Producing aluminum-coated iron or steel
US 2444422 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Patented July 6, 1948 UNITED STATES PATENT oerce PRODUCING ALUMINUM-COATED IRON STEEL Victor H. Bradford, Upper Montclair, N. J., as-

signor to Specialties Development Corporation, Bloomfield, N. J., a corporation of New Jersey 1 No Drawing. Application September 7, 1942,

Serial No. 457,582

- iron and steel.

Another object is to provide an impervious aluminum coating for iron and steel which precoating.

Another object is to provide iron and steel articles having an improved aluminum coating.

Another object is to provide aluminum-coated iron or steel articles, which simulate aluminum articles and are as serviceable as aluminum articles, but can be produced at a lower cost.

Another object is to provide an improved process of coating iron or steel with aluminum.

A further object is to provide a simple and inexpensive process for coating iron or steel with aluminum, and bonding or alloying the coating to the iron or steel. I

Other and further objects of the invention will be obvious upon an understanding of theillustrative embodiment about to be described, or will be indicated in the appended claim, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

' In accordance with the invention, these objects are generallyaccomplished by subjecting an iron or steel base to a nitrogenous medium, coating the "iron or steel base with aluminum, and causing the coating to be bonded to the base. The nitrogenous medium forms a superficial layer on the iron or steel which serves to bond or alloy the coating thereto.

Any suitable iron or steel may be used in con- 7 1 Claim. (Cl. JAB-46.6)

negligible aluminum content. The aluminum in such iron or steel is present as an impurity, rather than as an alloying ingredient.

Also, low alloying, high tensile steels, which a may be formed into structural members and the like, are suitable for use in connection with practicing the invention. Such steels usually contain between about .10 and about .40 percent of carbon by weight. The aluminum content thereof is negligible, and is present as an impurityyrather than as an alloying ingredient.

The nitrogenous medium employed, preferably, is nascent nitrogen (N) produced by cracking ammonia gas at temperatures between about 1100 and about 1150 F. 1

Any suitable types of commercially available aluminum may be used, ranging from substantially pure aluminum to various alloys of aluminum, wherein aluminum is the principal metal.

The aluminum coating maybe applied to sheets or plates, or the like, of iron or steel adapted to be thereafter formed into articles, and may likewise be applied to prefabricated iron orsteel articles. By the term base, as used herein and in the appended claim, is meant the surface of sheets, plates or the like, or the articles made therefrom.

In practice. the ferrous base to be coated is first cleaned and degreased in any suitable or. customary manner. The base is then subjected to nascent nitrogen at a temperature between about 950 and about 1150 F., for a suillcient duration of time to produce a nitrogenized or nitrogen treatedidentified as iron nitride. lhese needles have a high afilnity faraluminum and readily alloy with aluminum, as will be described hereinafter.

The nitrogen treated or nitrogenized ferrous base is then coated with aluminum by electroplating, by dipping in a bath of molten aluminum, by spraying with aluminum, or in any other suitable manner. The thickness of the coating may vary, depending upon the intended use of the coated base, or the character and intended use of the article or member made therefrom. For example, the coating may have' a thickness of between about-.0003 and about .010 inch.

After the coating of aluminum is applied, the base is passed through or is placed into a suitably heated furnace, oven or the like. Where the shape 0f the base permits, induction heating methods perature of between about 400' and about 950 F.

higher heating temperatures, the heating period may be slightly shortened.

The heating step causes the portion of the aluminum coating bontiguous with the layer of nitrogenized iron to difiuse into the layer. Due to the afiinity between aluminum and iron nitride, the portion of the aluminum coating in contact with the layer combines with the iron nitride to form a compound or complex comprising iron, aluminum and nitrogen. In this manner, the

aluminum is atomically bonded or alloyed with the ferrous base, to form a strong bond between the coating and the base. This enables the base to be subjected to severe bending strains, deep drawing operations or polishing operations without chipping, flaking, cracking, peeling or spalling of the aluminum coating.

From the foregoing description, it will be seen that the present invention provides improved aluminum-coated iron and steel, and a process of producing the same. The coating is integrally bonded or alloyed to the iron or'steel and will remain permanently thereon. The coating can readily withstand any rough usage to which it may be subjected.

The process employed is simple and inexpensive and does not involve the use of complicated machinery, equipment or apparatus. Iron or steel plates, sheets or the like, coated in accordance with the process. herein, can be readily fabricated into articles heretofore made of aluminum. Also, the articles formed of iron or steel may be thereafter coated with aluminum by following the process of the invention. The process likewise may be employed in connection with aluminum 4 coatings on previously used iron or steel articles or members, to recondition the same.

As various changes may be made without departing from the spirit and scope of the inven- '7 tion, it is desired that the foregoing description be understood as illustrative and not in a limiting sense.

I claim:

The process iof aluminum coating an iron or steel base, which comprises subjecting the base to nascent nitrogen at a temperature of between about 950 and about 1150 F. for a time suflicient to producea superficial layer of iron nitride having a thickness of between about .0005 and about .001 inch, providing the base with an aluminum coating having a thickness of between about .0003 and about .010 inch, and subjecting the base and the coating to a temperature of between about 400 and about 950 F. for a period of between 30 minutes and about 10 hours to form an iron-nitrogen-aluminum complex between the base and the coating adapted to alloy the coating to the base.

VICTOR H. BRADFORD.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,409,017 Ortiz Mar. 7, 1922 1,552,041 Crapo Sept. 1, 1925 1,736,921 Kinzel Nov. 26, 1929 2,046,036 Rodriguez I. June 30, 1936 2,135,388 Dellgren Nov. 1, 1938 2,197,622 Sendzimir Apr. 16, 1940 OTHER REFERENCES Chemical Abstracts, September 20, 1944, page 4900.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1409017 *Dec 23, 1914Mar 7, 1922Gen ElectricCompound metal body and method of making the same
US1552041 *May 9, 1924Sep 1, 1925Crapo Frederick MProtected metal and process of making it
US1736921 *Feb 13, 1928Nov 26, 1929Electro Metallurg CoCase nitrification of steel
US2046036 *Jan 19, 1934Jun 30, 1936Ortiz Rodriguez AnselmoMethod of coating ferrous bodies with other metals
US2135388 *Mar 1, 1937Nov 1, 1938Crown Cork & Seal CoMethod of coating iron or steel articles with aluminum
US2197622 *Apr 22, 1937Apr 16, 1940American Rolling Mill CoProcess for galvanizing sheet metal
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2697869 *Apr 23, 1948Dec 28, 1954Armco Steel CorpProcess for making aluminum coated material
US2704512 *Dec 12, 1951Mar 22, 1955 Metal printing plate and method of
US2752265 *Jul 24, 1951Jun 26, 1956Whitfield & Sheshunoff IncMethod of producing a porous metal coat on a composite
US2797174 *May 23, 1952Jun 25, 1957Lockheed Aircraft CorpMethod for providing protective metal coatings on metal
US2835566 *Nov 1, 1956May 20, 1958Pechiney Prod Chimiques SaAluminum manufacture
US2845365 *Sep 15, 1953Jul 29, 1958Harris Transducer CorpAluminum iron alloy
US2892924 *Jan 24, 1957Jun 30, 1959 Electrode for melting and arc welding
US2898251 *Nov 19, 1956Aug 4, 1959Jones & Laughlin Steel CorpAluminum coated steel article and method of producing it
US2965963 *Sep 21, 1956Dec 27, 1960Jones & Laughlin Steel CorpAluminum cladding of steel
US3468119 *May 31, 1967Sep 23, 1969Takeo KagitaniSteel-cored rod as a component of an aluminum cable,the cable and process of making the rod
US3907611 *Nov 10, 1972Sep 23, 1975Toyo Kogyo CoMethod for making ferrous metal having highly improved resistances to corrosion at elevated temperatures and to oxidization
US4659628 *Jul 9, 1985Apr 21, 1987Honda Giken Kogyo Kabushiki KaishaMethod of presubstrate treatment for painting utilizing a gas soft nitriding
US7036698 *Jan 16, 2002May 2, 2006Yakima Products, Inc.Boat loading system for a vehicle
US8556146Jun 7, 2010Oct 15, 2013Yakima Innovation Development CorporationBoat rack
DE19758140A1 *Dec 19, 1997Jul 8, 1999Mannesmann AgVerfahren zum Erzeugen von Metallprodukten aus Verbundwerkstoff
Classifications
U.S. Classification148/220, 148/240, 428/653, 428/941
International ClassificationC23C28/00
Cooperative ClassificationC23C28/00, Y10S428/941
European ClassificationC23C28/00