US1507845A - Carbonizing compound and process of making and using it - Google Patents

Description

Sept. 9*; 1 924. f 1,507.845

/ S. B. MATHEWSON ET AL CARBONIZING COMPOUND AND rRocEss OF MAKING AND USING IT Original Filed April 5, 1922 III/l IIIIIIIIIII III/II gwumtozsz 549,274 now Patented Sept. '9, 1924.

JUNITED- STATES PATENT ornca.

STANLEY B. ILATEEWSON AND W LTER x. JAMISON, E SPRINGFIELD, onro, As-

sIGNoEs To wALTEE x. JAMISON, STANLEY n. MATHEWSON, HOWARD F. MARS- ToN, MRS. w. x. JAmsoN, AND mas. s. B. MATHEWSON TRUSTEES on THE LECAR cAEBoN COMPANY, A TRUST ESTATE, or SPRINGFIELD, OHIO.

omomzme COIPOUND AND PROCESS or MAKING AND USING IT. A

To all whom it may concern:

Be it 'known that we STANLEY B.

MATHEwsoN and'WAIJrER J MIsoN, citizens of the United States, residing at 6 Springfield, in the county of Clark and State of Ohio, have invented certain new and useful Improvements in Oarbonizing Compounds and Processes of Making and Usin Them, of which the following is a 10 speci cation, reference being had therein to the accompanying, drawing. j

Our invention relates to a carbonizing compound and the process of making it and using it for carbonizing'metal, and in par- 1 ticular case hardened steel. The object of our invention is to utilize scrap leather by the treatment'of our invention hereinafter described and claimed.

' An additional object, of our invention. is to provide a new product by this treatment which may be utilized as a carbonizing material. 1

It is a further object of our invention to provide a method-of utilizing our new prodnot incase hardening metals such as steel inorder to provide avery deep case in the minimum of time and economically.

This is a division of application No. Patent 1,471,563, of October 23, 1923.

Referring to the drawings:

1 is a carbonizing can;

furnace in which the carbonizing can is placed with the scrap leather in order to reduceit to the form ofthe product now in question;

Fig. 3 is a diagrammatic view of the rolls and screen for determining the size and grade of the resulting carbonized product;

Fig. 4 is a crossasection of a piece of steel before treatment with this carbomzmg material; ,1 I

Fig. 5 is a similar view after carbomzation showing the case. Q, n

, Fig. 6 is'a section. of a carbonizmg' box packed with the carbonizing material 1nvolved herein showing the articles beingcarbonized and the arrangement of their packing. It W111 be,understood that the forego ng drawings ar diagrammatic merely and are only for the purpose of illustration.

Referring tothedrawings in detail, 1 is a carbonizing can or metal container havin a lid 2 with apertures 3 in the lid thereoi Serial no. 549,274. Divided. and this application filed August 7, 1922. Serial No. 580,225.

The scrap leather is placed in'this can and v the can is placed in an oven 4. This-oven 1s heated by any desired meansv as for in,-

stance by burnerssuch as at 5. It will be understood thatthis illustration of the. burners is typical only and that any kind of heating apparatus I may be employed. The cans are covered and the lids are tight fitting. The openings 3 are provided in --sealed with the exception of the regular ventilation therefor. It is customary to allow the furnace to remain closed for about six hours, after which time the containers can be removed and the finished product may be removed from each one of the individual containers. It is thenv crushed between the rollers 66 and screened by the screen 7 which is preferably about of a mesh. The purpose of this is to reduce it .to'a suitable size for carbonizing purposes. Flg. 2" is a 'diagrammatlc view of the Process of hardening steel.

The finished product thus secured is used as follows. The parts to be carbonlzed are thoroughly cleansed in an alkali solution- The top of the box is sealed with fire clay as at 11. It is the preferred practiceto place a layer of the carbonizing material,

then a' layer of parts separated from one another by the carbonizing material, a layer "of carbonizing material and another layer of parts, andso on. The whole packlng is covered with a layer of the carbomzmg material;

5 the cans to permit of the adjustmentof the' internal pressure and to permit of the escape been brought up to If desired the lid may be of metal and sealed with fire clay. Any common practice of this sort maybe followed. The boxes are then placed in a carbonizing furnace and the temperature brought up to 1700 de ees F. and held at this temperature for a ut three hours but this time and temperature varies upon the depth of case desired, the size of the parts to be carbonized and the size of the carbonizing boxes.

In theevent the furnace is cold when the boxes are placed therein a proportionatelygreater time will be necessary to effect the esired result.

The boxes emplo ed are usually about eight and one-hal inches in diameter eleven inches deep and walls about thick. It takes about three hours to bring a hot furnace up to the temperature of 1700 degrees, the temperature used for carbonizing.

For instance, in the case of carbonizing, S. A. E. 10 20 steel, it has been found good ractice with this carbonizing material to iiold the carbonizing heat at 17 00 degrees F. for five hours when packed in a box of the above mentioned dimensions in order to obtain a depth of case.

The preferred method after this tempera- I ture has been maintained this desired length of time is to allow the case hardened steel parts to cool in the carboni'zing boxes beforethe are exposed to the air.

%e do not desire to confine our invention to any particular type of furnace for the heat treatment. An open type furnace may be employed in which the temperature has 1450 degrees F. beforethe parts are placed in the furnace. It will twenty minutes to bring a part, speaking in terms of diameters, up to 1450 degrees.

The parts are then removed and quenched in brine or oil. It will be understood that these parts are always removed from the ace and quenched on the rising heat.

In the second method. a salt bath maybe used and the parts are immersed in this solution. After the solution has been brought up to 1450 degrees F. the parts are removed and quenched in brine or oil. This type of furnace is usually designated a-cyani e fur- I nace. It will be understood that thefire does not come in direct contact with the I work as a cast iron tank is placed in the furnace and the salt, solution is placed in the tank and melted by the heat coming in contact with'the outsideof the tank.

It will be further understood that it is Eereferred by us that all quenching solutions retained at as low a temperature as ble, which is accomplished by any well known means such as circulating the solution throu h coolin coils.

Re erring to igs. 4 and 5, 12 i a specimenofsteeland 13 isthecase.

be case hardened.

' apfiroximate.

pon analysis the ash will usually dovelop a ferric oxide color. The volatile matter consists of various gases. In these gases a varying amount of ammonia will be found and the usual reaction to litmus will be alkaline. a

- While we have shown and described certain features as constituting our invention, it will be understood that parts have been shown for purposes of illustration only, and that we do not desire to avmg thus fully described our invention, what we claim as new and desire to se cure b Letters Patent, is:--

' 1. he process of case hardenin metals consisting in heating the metal in t e presence of carbonizing material consisting. of ash moisture and fixed carbon containing material volatilizable b the heat to carry the carbon into the sur ace of the metal to be case'hardened. i

' 2. The process of case hardening metals 1 consisting in heating the metals m an air tight vessel in thetpresence of carbomzm material consisting of ash moisture andfix carbon containing material volatiliaable by 3. The process of case hardening metals '110 consisting in heating] the metal. in an airtight vessel'to approximately 1700 F. n thepresence of car onizin materialconsisting of ash moisture and xed carbon, the last-- containin material volatilizable by the heat to carry is e carbon into the surface of the metal to be case hardened.

4. The process of case hardening metals consisting in heating the metal in an 'a1r-' tight vessel in the A material to a temperature approximately 1700? F., the carbonizing material'contaming ammoniacal volatilizable gases to carrythe carbon into the surface 0 the metallic y 125 In testimonywhereof, we aflix our sigmatures. 4

STANLEY BQMATHEWSoN. WALTER x. JAMISON.

be limited to such '90 details, as obvious modifications will occur) to lpersons skilled in the art.

presence of carbonizing

Images