USRE11570E - Charles walrand and eugene legenisel - Google Patents

Description

' .UNITED ST TES PAT NT OFFICE.

:QHARLES WALRAND Al ID' EUGENE Lncnmsst, or PARIS, FRANCE.'

P'Roc ssoF MANUFACTURING STEEL.

SPECIFICATION forming part of Reissuad Letters-Patent No. 11,570, dated September 29, 1896.

Original No. 563,816, dated August 22,1895. Application for Reissue filed November 12,1895- Serial No. 568,740. Patented in France June 29, 1891,110- 214,514; in England S ptember 23, 189L110. 16,178; in Belgium September 23, 1891,150- 96,499; in Germany September 24, 1891,1l'o 6 4,950, and in Austria-Hungary September 25,1891. Nu.16,542 and No. 35,534.

Patent in France, dated 'J une' 29, 1891, No. 214,514, in, Germany, dated September 24,

1801, No. 64,950, in Austria-Hungary, dated September 25, 1891, No. 16,542 and No. 35,534; in England, dated September 23, 1891, No. 16,178, and in Belgium, dated September 23, 1891, No. 96,499,) of which the following is a f u l 1, clear, and exact description.

In conducting the manufacture of steel on a small scale a considerable percentage of the heat of -thechargeof-maetal int-he eonverter is lost, and this is dueto the early and too .rapid combustion of the silicon, result :ing in a solid product, silica. The heat developed in the bath is due-to the combus tion of the silicon. Thus, as in the process of dephosphorizing molten cast-iron, inwliich process thephosphorus-is burned last, the silicon should be oxidized only after the elimination of the carbon,-in"order that the least possible amount of the heat may be carried away by the gases resulting f min the To have foundcombustion of the carbon. in thus operating that, there was a considerable gain in heat, which permitted the mak-- ing of; steel at a suitable temperature in small' quantities.

The object of our process is to produce cast-steel with small charges, (say, approximately, one hundred kilograms) thereby rendering the improvements substantially serviceable for making said metal on a limited scale. 1

Instead of using cast-iron containing a considerable proportion of silicon, wetreat in the acidoperation any cast-iron containing silicon, without regard to the degree of the latter, provided said cast-iro'nicontaihs sufiicienthcat at the period when it is poured into the converting apparatus. We have found that with different qualities of cast-iron containing silicon in from 1.5 to threeper cent, the l'mal 'tenn-ieraturc of the bath resulting from the small charge which we employed -\-'aried very little, the brevity of the operation constituting an extremely important factor. If at the period when the oxidizing operation. is .tcnninat cd, (which in the converting apparatus is seen by'the lowering of the flame,)-a certain quantity of silicon is added to the bath under the form of an alloy and the blowing be continued, a vemarkablc phenomenon isprOduced. The flame disappears entirely,- leading to the .belief that the operation is onl-y'at the commencement of the blowing period; but it will be seen that the temperature gradually rises,

and it is therefore the comb'ust-iou'of the silicon" i-hatheatsthe-bath.

According to the proportions of silicon --added,--varyin of conrse,-with the nature of the metal and the wcightof the charge under treatment, the blowing is continued to the period when the flame of the carbon is seen to rcappcau. The said blo w which appeared cold, becomes extremely hot upon the addition of the silicon alloy. Generally the operation is terminated at this point, and to insure that the cast metal has reached a suitable condition a sample is taken. The metal ist-hcn cast as usual. The silicon alloy can be introduced either cold. at a rod heat, or,

preferably, in a molten condition to avoid any lowering of the temperature.

W' e do not limit ourselves to the use of sili-v ,con but propose to use any other agent which,

.undcrthe above specified conditions, will be capable of raising, by its combustion Within the bath, the temperature thereof; Thus in a basic operation the bathwould be liquefied after the blowing penod by the addition of a rich alloy of phosphorusand by continuing to blow.

In conducting the manufacture of steel on alarge scale by the Bessemer or the Thomas process the addition of silicon, phosphorus,"- or any other combustible agent, 'under the conditions specified above, co did also be made with equally atisfactory resul-ts. It will be undeistood that the final addition. of silicon as practiced byus has in nowise the purpose ordinarily in view of producing'the deoxidation ofthe steel bath. in our process the object of the addition is to increase the temperature of the bath, thus enabling the employment of small charges and the production of steel on a limited scale andat a suit-,

able temperature; As stated, the importance and effect of the addition varies with the size of the charge treated and the nature of the cast-iron under treatment. The addition of silicon or its equivalent-could also be made a little while before or alittle while afterthe Ilanie drops, as the result obtained will be substantiallythe same, assuming the purpose of the addition, as before stated, being only to increase the temperature, so as'to render the metal more fluid heforecasting. \Ve do not contemplate merely augmenting the amount of silicon in the bath, asthis can be secured either by mixing in crucibles or by -col d or warm additions to the ladies into which the convert-in g apparatus discharges. flo secure the desired effect when. -operatingwith phargesot two hundred kilograms, fore-21ample, it will be well toadd, saygtfrom'five -to ten per cent. of fcrro-silieon containing ten ing witnesses.-

per eent of silicon, which, however, does not avoid the necessity for the final deoxidizing addition.

\Ve'niay employ an ordinaryBessemer eon- Verter having facilities for lower, upper, or

lateral air-feed. I

-\\"e claim The herein-described improvement-in the manufacture of steel from metal originally containing silicon, which consists in treating; the same to eifectpriinary combustion and oxidation, adding silicon approximately at the period whenthe primary combustion is effected and the oxidizing operation terminated, and continuing the blowing operation In testimony whereof we have signed this specification in the'presenceof two subscrib- CHARLES v'WALRAND. EUGENE LEGENISEL: .Wil:-nesscs: o

CLYDE SHRoP'snmE, .B; DELAMOUR,

after such additi on ,suhstantially as set forth. 4,0