US1207848A

US1207848A - Process of carbonizing and hardening metal.

Info

Publication number: US1207848A
Application number: US83529814A
Authority: US
Inventors: Nelson H Bray
Original assignee: Individual
Current assignee: Individual
Priority date: 1914-04-29
Filing date: 1914-04-29
Publication date: 1916-12-12
Anticipated expiration: 1933-12-12

Description

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, such eflects are impossible in steel hardened;

PROCESS 01F CARBONIZING AND HARDENING METAL.

ll 26W 84%.

No Drawing.

To all whom it may concern:

'Be it known that T, "NELSON H. Bangs citizen of the United States, residing at 1216 Fifth avenue, in the city and county of San Francisco, State of California, have invented a new and useful Process of Carbonizing and Hardening Metal, of which the following is a specification. 1 g

This invention relates more particularly to the process ofhardening steel by the direct application of an oxy-acetylene' flame, in combination with othercarbonizing elements, and chilling.

In the following description a simple manner of putting this invention into practice will be disclosed, but ll do not wish to be understood as confining this invention to the specific mode of operation, or the ingredients set forth, as many variations may be introduced, well within the spirit of this invention as'defined in the claims succeeding the description.

The commercial type of oxy-acetylene apparatus delivers through a blow-pipe a flame, composed of acetylene gas and oxygen under pressure. The proportions of acetylene gas and oxygen can be varied by regula tion, for the particularresults desired. In

the present invention the acetylene predominates, its high carbon content being taken advantage of as a carbonizing agent.

The present process must not be confused with the well known process of case hardening, that consists in forming a superficial thin skin of hard metal overlying the mass of metal'upon which it is formed. Case hardening serves very well under certain conditions, but practice has demonstrated that it will not for instance withstand heavy pounding and rolling action without spalling orsplintering, the more ductile metal beneath causing the hard skin to separate from the main body; 'a perfect demonstration of the superficial character of case hardening.

The process, forming the subject of this invention, alters the physical nature of the metal so treated, penetratingto-a considerable depth, preserving or increasing the toughness, while raising the temper or hardness to the maximum. Spalling y by this process.

The mode of operation in the practice at, this invention includes the direct ap h tion to the surface of the nietal of the Specification of Letters Patent.

Patented Dec. t2, 193W.

Application filed Ap1'i129, 1914. Serial No. 835,298.

the highly divided carbon contained within the acetylene and its byproducts of combustion are driven into the porous metal,

or absorbed by it, to the depth to which the temporarily increased porosity extends, during the heating period. The absorption uof carbon and other hardening elements, during this period of superporosity can be accomplished, by the surface application of commercial oyanid of potassium, followed by the application of a solution of salt .and copper sulfate in water. This solution should be applied as nearly as may be to the surface of the heated metal, within the zone of the flame projected against it. When the llmit of absorption has been reached, the process of hardening is completed by'the direct application of a chilling bath, such as brine or other mixtures flowed .over,"or ap plied to the heated surface. v

This hardening process may bet-localized that is to say a given area of'the metal to be treated may be hardened, without altering the characteristics of the surrounding area; on the other hand the results are so uniform following" the use of this process, that a piece of metal progressively treated will show no appreciable variation in hardness throughout the entire area treated at different times. The development of the oxy-acetylene art has not yet progressed to the point where a considerable volume of flame is available from a single blow pipe.

At present large areas are bein treated by this process by arranging the b o-wipes in gangs to increase the volume of ame to cover the desired area.

Having thus described this invention what I claim as new and desire to secure by Letters Patent is:

1.. The process of earbonizing metals which includes heating the metal to a highly absorbent degreeby the direct application of an acetylene flame.

3. In the process'ofhardening metal by carhonizing, the step consists in heatby the direct application of an oxy-acetylene flame, and applying cyanid of potassium, and a solution of salt and copper sulfate, during the period of high temperature.

6. The process of treating metal which includes heating the metal to a high degree by the direct applicationof a high temperature flame, and applying cyanid of potassium, and a solution of salt and copper sul-- fate during the period of high temperature.

7. The process of carbonizing metal comprising heating the metal to a highly absorbent degree by the direct application of an open acetylene flame.

8. The process of carbonizing metal, which includes heating the metal to a temperature just short of the Welding temperature by the direct application of an acetylene flame containing an excess of acetylene.

In testimony whereof, I have hereunto set 30 my hand this 22nd day of April, 1914.

NELSON H. BRAY. Witnesses:

BALDWIN VALE, A. J. HENRY.