US1428087A

US1428087A - Rust-resisting steel and method of producing same

Info

Publication number: US1428087A
Application number: US479683A
Authority: US
Inventors: James H Gravell
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-06-22
Filing date: 1921-06-22
Publication date: 1922-09-05
Anticipated expiration: 1939-09-05

Description

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To aZZ whom it may concern:

Be it known that 1, Jules H. GRAVELL a citizen of the United States, residing at llllkills Park, in the county of Montgomery and State of Pennsylvania, have invented a new and useful lm rovement in Rust-Resisting Steel and Methods of Producing Same, of which the following is a specification.

This invention relates to iron and steel and it is particularly directed to rust resisting steel.

The object of the invention is to provide rolled steel that rusts with dilliculty or is not so liable to rust as ordinary rolled steel found on the market at the present time.

According to the present methods of making rolled steel and iron, the steel billet is heated to a high temperature and rolled to the desired shape. This produces the hot rolled steel of commerce which is covered with a substantial coating of oxide which causes it to look black. lit a metallic or bri ht finish is required, the hot rolled steel is pickled with an acid to remove the oxide and then rolled or drawn cold to secure the high finish. The term rolling will be used to include drawing. Ha thin plate or strip is required, it may be processed several times. is annealed during which great care is exer cised to prevent the air from contacting with 'the metal while it is heated, as otherwise it would be oxidized and would have to be again pickled to remove the oxide or scale.

Steel produced by these methods rusts rapidly while stored or being shipped. lit is natural for the metal to rust in the atmosphere, but the natural rusting is accelerated by the presence of impurities received in the pickling operation, such for instance as sulphurlc and other acids and salts.

l have discovered that it a thin coating of iron phosphate is given to the metal hetore rolling and that if this coating is rolled onto or into the surface in the rolling eration, the rust accelerators are neutra ized and the natural rusting tendencies of the metal are greatly reduced. Metals treated according to my process are distinguished from other metals by a darker looking surface and by their freedom from rusting, and they may be shipped or stored for long periods without danger of rusting although Between the cold rollings the metal RTUhT-SISTING STEEL AND HETEQD @151 PRODUGING SAME.

Application filed June 22, near. serial Ito. Matti not protected by a coating of oil which is now the universal custom.

To process the metal according to my invention, it may be first hot rolled and then freed of its oxidized surface by any of the well known methods, such as etching and sand-blasting or sudden chilling and it may he washed. It is then given a coating of iron phosphate. This may be done by boiling the metal in a dilute solution of hosphoric acid (one pound of absolute acid to 100 pounds of water) or the metal may be simply dipped in a solution of phosphoric acid and Water (one pound of acid to 20 pounds of water). The water may be hot or cold. Another method of forming the phosphate coating on the surface is to apply a coating of a thermally decomposable phosphate such as ammonium or aniline phosphate and to then heat the metal to liberate phosphoric acid which attacks the surface forming the phosphate coating. Ur an acid salt of phosphoric acid may be applied to the surface which will have sufficient acid reaction to produce the desired coating.

Alter securing the phosphated surface, the metal is then rolled. It may be allowed to thoroughly dry first if the Wet methods mentioned above have been used or the metal may be passed through the rolls in the wet condition.

The metal resulting from this process is dull in appearance and has the advantageous property of not readily rusting and it may he painted without danger of the metal rusting under the paint as the cause for this is neutralized in my process by the action of the free or combined phosphoric acid.

It will be obvious art that modifications may be made in details of procedure and in its chemical aspects the range of equivalents is wide, hence I do not intend to limit the invention as to such matters or otherwise than as the prior art and the appendedclaims may require.

I claim:

1. The method of producing rust resisting steel consisting in treating the steel with phos horic acid and 't on rolling the steel.

2. The method of producing rust resisting steel-consistingin pickling the steel, then treatin the steel with phosphoric acid, and then ro ling the steel.

3. The method of producing rust resistto those skilled in the ing steel consisting in. pickling the steel, washing the steel to remove the pickle then treating the steel with phosphoric acio, and then rolling the steel.

4:. The method of producing rust resist ing steel consisting in forming a coating of iron phosphate on the surface of the steel and then rolling the steel.

5. The method of treating steel to prevent 10 it from rusting Which consists in rolling into teases?