US961462A - Process of treating metal sheets. - Google Patents

Description

, A. RIDD. PROCESS OF TREATING METAL SHEETS.

APPLICATION FILED mm: 14, 1909. v

Patented June 14,1910;

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I l/ In I! l'! i IIIII/IIIIIIIIIII i 1) I A. RIDD.

PROCESS OF TREATING METAL SHEETS.

APPLICATION FILED JUNE14, 1909. I

Pamnted June 14, 19w.

2 SHEETS-SHEET 2f awouwgo "wvitnaaoeo AMBROSE BIDD, 0B NEWPORT, KENTUCKY.

PROCESS OF TREATING METAL SHEETS.

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Specification of team Eatent. Patented June 1a,- 1910.

Application filed June 14, 1909. Serial No. 502,087.

To all whom 'it may concern:

Be it known that I, AMBROSE Rum, a citizen of the United States, residing at Newport, in the county of Campbell and State of Kentucky, have invented a new and useful Process of Treating Metal Sheets, of which the following is a specification.

This invention has reference to the process of treating metal sheets, and it is the object of the present invention to insure uniformity of product-ion so that the finished sheets shall be all alike.

In order that the present inventionmay be more clearly understood attention is called to the usually employed method of treating metal sheets.

The sheets are first annealed in an airtight box, or they are piled on a heavy slab, it being customary to treat from one hundred to five hundred sheets at a time. If the slab be used then the sheets are charged into a muffle in bulk, that is, they are piled on the slab outside the furnace and are then introduced therein and the entire mass of sheets is then annealed while lying fiat on the slab. The temperature of the furnace is then lowered until a black heat is attained at which point the sheets are taken from the furnace in bulk and while still resting on the said slab are carried in bulk to the rolls to be then fed sheet by sheet through the rolls, after which they are re-' piled, on the opposite side of the rolls, on another heated slab and after all the sheets have been rolled they are then charged into a furnace at a very low temperature and then allowed to cool o'fi. Also when it is desired to oxidize certain of the sheets they are turned over singly while at a dark red heat and are then taken to the rolls and finished as before except that the annealing is done in the regular air-tight box.

In accordance with the present invention the sheets are fed into the mufiie chamber again enter a similar conduit at the opposite side of the rolls in which conduit the sheets cool off. For some purposes the conduit may be omitted and the sheets taken directly from the furnace in full and free contact with the atmosphere and then passed through the rolls, or the rolling may be omitted.

The invention will be best understood from a consideration of the following detail description taken in connection with the accompanying drawings forming a part of this specification in which drawin s- Figure 1 is a longitudinal vertica section through a furnaceconstructed in accordance with the present invention. Fig. 2 is a section on the line A--B of Fig. 1. Fig. 3 is a longitudinal section of the discharge end of the furnace and the conduits leading to and from the finishing rolls. Fig. 4 is a section on the line CD of Fig. 3, more distant parts being omitted. I

Considering first the apparatus used in the carrying out of the process herein disclosed, which apparatus also forms a part of the present invention, there is shown a furnace 1, the showing being in part typical or diagrammatic since the structure shown is more illustrative than actual, although a furnace constructed as shown will operate for the purposes of the present invention. It is not to be understood, however, that the showing of the drawings is at all mandatory since the furnace there shown and cooperating parts may be greatly'varied while still retaining the salient features of the invention. Within the inclosing walls of the furnace and spaced therefrom so as to form a combustion space 2 there is a mufiie chamber 3 accessible at one end through a series of doors 4. The floor 5 of the muflie chamber is shown as slanting, but of course this floor [may be level if so desired. The openings closed by the doors 4 lead directly to the floor 5. Beneath this floor 5 are located furnaces 6 shown as three in number and extending laterally to the length of the muffle chamber, but this arrangement may also be varied as desired. It will be understood that the furnaces 6 lead to the combustion space 2 and that a suitable stack or chimney is connected to this combustion space for the escape of products of combustion after circulating well through the space 2 so as to thoroughly and uniformly heat the mufile 3.

A pipe 7 leads into the muflie chamber? and is thereprovided with a discharge nozzle 8 of any suitable type. The pipe 7 comes from .a suitable sourceof sup y of superheated steam or in lace o siaperheated steam any other suita le non-oxi izmg1 gas maybe conducted into the mufilethrou the pipe 7. The purpose of this pipe w appear further on.

The effect of superheated steam on a late at a cherry red heat is to roduce a b u1sh coat or oxldation of the sur ace of the sheet, but such oxidation is so extremely thin as to have no practical value as a protective coatin therefore superheated steam may be define as practically non-oxidizing.

At the end of the furnace remote from the doors 4 and op osite the middle door is an opening 9 and om this opening there leads a conduit '10 ter'minatin at finishing rolls 11 and be 0nd these ro s is another conduit 12. ithin the conduits .1012 are rollers 13 forming supports for the sheets indicated at 14 on their wa through the conduit 10 to the finishing ro s and through the conduit 12 after leaving the finishing rolls. Adjacent to the opening 9 the conduit 10 carries feeding rollers 15. and extending throu h both conduits 10 and 12 are pipes 16 an 17 res ectively having numerous perforations. T ese pipes are designed to carry superheated steam or hot air for a'purpose which will presently appear.

-In accordance with the method of treatment of the present invention the sheet metal plates 14 are introduced into the muflie chamber 3 through the doors 4:,

usually the side doors, and are set on edge against the side walls of the mufiie chamber, this permittin the sheets to be heated while in a separate condition so that the sheets become heated uniformly throughout and are uniformly subjected to any oxidizing action which may take place. After the sheets have been properly heated they are laid down flatwise on the bottom of the muflie chamber to form a ile which is moved to the middle oint o the chamber in line with the conduit 10. Now the sheets are fed one at a time-or in acks to the feed rolls 15 and by the latter along the conduit 10 to the finishing rolls 11 and on leaving these latter into the conduit 12. During the heating of the sheets superheated steam or other non-oxidizing or practically non-oxidizing gas in introduced into the mufiie chamber through the pipe 7 so that the sheets are protected by the ressure thus established within the muflie c amber from the action of air entering through the openings normally closed by the doors 4 when the latter are opened for the purpose of handling the sheets and the edge discoloration so noticeable in sheets as heretofore treated is thereby avoided. Superheated steam is introduced into the conduit 10 by means of the pipe 16 and the tem erature of the sheets 14 as they passto the nishing rolls is thereby maintained. Steam is or may be introduced intothe conduit 12 by means of the pi e 17. For oxidizin metal sheets they are introduced into the rnace 1n the manner described and are brought to the required annealing temperature and then, if necessary, the temperature is gradually lowered while the sheets are still within the muffle and when conditions are roper for exposing the plates the door is I ifted and the plates or sheets are fed through the door singly until all have been discharged from the furnace. By this means the sheets are uniformly heated and uniformly exposed to the oxidizing influence of the atmosphere and a uniform product is the result. When it is desirable to present the sheets to the finishing rolls then the sheets Within the muffle are kept bathed in an atmosphere of superheated steam or other nonoxidizing or practically non-oxidizing gas under suflicient pressure to prevent the entrance of atmospheric air to the mufiie when the doors are opened for the necessary handling of the sheets. Steam is caused to escape through the perforations in the pipe 16 and into the conduit 10 so that the sheets tained as they travel from the muflle to the rolls. After leaving the rolls the sheets pass through the conduit 12 into which steam is introduced through the perforations in the pipe 17 and the sheets are thereby bathed in a non-oxidizing atmosphere but which is so regulated as to permit the sheets to cool down so that when they reach the atmospheric air the are cooled sufliciently to be no longer oxi ized thereby and the annealing to which these sheets have been subj ected is then not aifected by the cold atmosphere.

It is to be noted that the mufile chamber is rendered proof against the introduction of doors for the purpose of introducing sheets i to be annealed or for the purpose of withdrawing such sheets from the muffle chamher, by the introduction of a non-oxidizing gas at suflicient pressure to prevent the entrance into the muflie chamber of the atmospheric air when the mufile is opened. Hot air may be introduced with the superheated steam and since superheated steam is practically non-oxidizing the mixture of superheated steam and hot air may be made to produce any degree of oxidation desired.

The present process forming the subject matter of this invention has marked advantages over prior processes in that there resu ts a umformity of color because each eenaea sheet is ex osed to the oxidizing influence of the air w ile'all the sheets are at the same temperature, the color and oxidation resultlng being therefore uniform. Furthermore, discoloring and overoxidation of the edges of the sheets, which has hitherto been unavoidable. is completely overcome by the present rocess.

It wi 1 be understood that the furnace shown and described may be used for and. is specially adapted to the heating of metal sheets that are to receive the Russia finish either by the ordinary hammering process or by the loose rolling or the friction rolling processes. The furnace disclosed 'is not here inclaimed, but this is not to be construed as a waiver of the right to make subsequent ap lication for Letters Patent therefor.

Vhat is claimed is:

1. The rocess of treating metal sheets consisting in heating the metal sheets, while on edge and in se arated relation one to the other, in a bath 0 practically non-oxidizing gas, and then withdrawing said sheets one by one from the heatin zone while maintaining them in a bath 0 non-oxidizing gas.

2. The process of treating metal sheets consisting in heatin the metal sheets in a muffle chamber in a ath of practically nonoxidizing gas at super-atmospheric pressure while said sheets are on edge, and then withdrawing said sheets from the mufile chamber one at a time while maintaining the supply of said gas in the mufile chamber.

3. The process of treating metal sheets consisting in heating the metal sheets on edge in a muflle chamber in a bath of practically non-oxidizing gas at super-atmospheric pressure, then layin said sheets flatwise one upon another to orm a stack, and

then withdrawing said sheets one at a time while maintaining the supply of said gas in the muflie chamber. 4

4. The process of treating metal sheets consisting in heatin the metal sheets in a muflie chamber in a ath of practically nonoxidizing gas at super-atmospheric pressure and then feeding the sheets to finishing rolls through a bath of hot non-oxidizing gas exterior to the muflle chamber to prevent overoxidation of the sheets and to maintain their temperature as they ass to the rolls.

5. The process 0 treating metal sheets consisting in heating the sheets in a mufile chamber in the presence of practically nonoxidizing gas at super-atmospheric pressure, then passing the sheets from the muflle chamber to ti finishingrolls through hot .non-oxidizjpg gas, and then cooling the sheets after passing the finishing rolls in an atmosphere of non-oxidizing gas.

6. The process of treating metal sheets consisting in heating the'sheets while on edge in a muffle chamber in the presence of practically non-oxidizing gas at super-atmospheric pressure, then laying the sheets flatwise one upon the other, then moving the sheets one at a time out of the mufile chamber to finishing rolls and maintaining about the sheets an atmosphere of hot nonoxidizing gas, and finally permitting the sheets to cool after passing the finishing rolls in an atmosphere of non-oxidizing gas.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

AMBROSE RIDD. Witnesses:

Jno. C. DE Moss. JOHN MOSPENS.

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