US743715A - Manufacture of steel. - Google Patents

Description

whether owing to the"-presencc of dissolved evil hereinbefore. referred to, and in accordas compared with ordinary samples obtained .To allwhont itmay concern? description is a specification.

; W Q 'TQT T new i srncnncnrron formin part'of L fetters Pa lpplication filed June 24 19.0.lr S

7 Be it known that I, ROBERT a. HnDFIEpn,- a subject of the King of Great Britain, and

a residentof Sheffield, county of York, England, have invented ail-Improvement in the lllanufacture-of, Steel, of whiclrthe following As aresult'of the decarboniz'ing and desiliconizing process in the production of steelby various pneumatic methods now'commonly practiced the 'fluid nietalbecomes permeated witli'ga'ses, and consequently very unsound,

gases, occluded oxygen, or other cause is not definitely known, and with the object of; remedying this condition it is usual tomake" additions of silicon,al umininni,=or other al loys of metals. While such additions are of some service,it is'doubtful Whether by their use the oxygenated fluid metal is in'practice' ever restored to its highest value.

My present invention has. for its object a novel method of obviatingor mitigating the ance therewith I control the oxidation of the molten metal during the process of its conversion into'steel by the introduction of manganese'to the-charge, meaning by the term conversion process the process of convert in g fluid pig-iron and scraper otherinixtures into steel. The introduction or addition of the manganeseis made in a practically continuous manner or at short intervals throughoutthe blow or charge or during the latter portionthereof or it may be addedafter the- (lisappearance of carbon from the charge, provided the blow is continued after such addition suiiiciently to practically complete the oxidation of all the added manganese. By this method of treatment I obtain a decarbonized and desilicouized iron exceedingly sound in theusual manner, and, furthermore, the use of expensive quicting additions, such as aluminium, may be largely or entirely dispensed with and a product obtained resembling the best qualities of crucible steel much more than does the product ordinarily ob.- tained.

To theproduct obtained in accordance with myiuvention the usualphysics maybe added,

' if desired, or the usual [steel -1ions; but when very soft steel is required tent navefiit, dated lvoveulbe r id, 119h3. I erialll0r65r80lsuch additions'may be dispensed with.

making addi-1- In some cases ,fo'r example, when: treating by pneumatic.proc'essesl add silieonbythe introduction of fe'rrosilicon or silicon during the blow,

be also made of siliconspiegel where a coinspiegeleisen ma'ybe use'd'.

My in'vention'may be practiced in the pro duetion'of steel in 'vari-ous ways; As one exother alloy of sons. to increase the temperature, and, on the other hand, to re duce the-temperature I sometimes :add white" pig-iron "or other similar prod uct: Yse may ample,"assu min g thata hargers being treated by any of thepn eumatic'processes for making "steel; if 3 manganese be added thereto'liy the introduction of 'ferromanganese containing;

say,-'e'ighty(80)" per cent. of manganese the decarbonized anddesilicon'ized iron will, as'f'" compared with products obtained in the usual manner, be -rnuch freer from the occluded gases,the productbeiug comparatively sound and much less red-short. A charge so pre- 'pared, when steel-making additions arebeing added, will be much sounder than one pre pared Without the employment of my invention. v Y

One practical mode of carrying out my invention is to add the ferromanganese or other manganese alley in a practically continuous manneri. e. at short intervalsthroughout the blow or charge, so as to keep the oxidation under control. Thus, for example, in a five-ton heat I may make a total'addition of, say, eighty pounds of eighty 80) per cent. ferromanganese, this quantity being added by introducing portions of it at intervals extending over the entire duration of the blowsay every one or, two minutes, more or less. Another mode of procedureis to add similar or greater quantities or smaller total quantities of eighty.(80) per cent. ferromanganese during only a portion of the blow. Thus, for example, there might be added during the latter partof the blow-say forty (40) pounds .of ferromanganese,distrib uted in eqn al on antities, or approximately so, at intervals of time, in lieu of making any addition of manganese during the first of the blow.

. 4 i The quantity of manganese added, as also the time or times at which the addition is made, may be varied according to requirenient. "be made as late as'during the-last quarter Thus in'some cases the addition might only of the .entire duration of the blow. Manganese might also, for the purposes of my invention, be added after completion of the Ordinary blow-th'at is, after the disappearance of carbon from the charge-care being taken to continue the blow after addition of the manganese sufficiently to complete or practically complet-ethe oxidation of all the added manganese. Usually, however, it will befound preferable to make the 'addition of I manganese before all the carbon has been oxidized, since the dropping ofth'e carbon fia-mewill then afiord a satisfactory indicathe processof conversion into steel will not give the desired result, because the manganese in this case will be oxidized too soon, whereas according to my invention the oxidation can be kept under control during the whole of the blow with minimum expenditure'.of manganese, besides which the manganese additions tend to reduce the percentage of sulfur presentgso that evenwhen using comparatively cheap stock satisfactory products may be obtained.

Having fully described my lnvention, what Patent, is

1. In the art ofsteel-making by the pneumatic method, the process oi controlling the oxidation of the molten metal during the conversion thereof intp steel, which consists in making successive introductions of manga nese to the charge subsequent to the cominencement and before the completion of the blow. i

2. In the art of steel-making by the pneumatic method, the process of controlling the oxidation of the molten metal during the con versionthereot' into steel, which consists in making successivev additions of manganese, at short'intervals', to the charge during the blow.

3. In the process of steel-making. by the pneumatic method, adding a temperature changing agent during the blow to vary the .I claim as new, and desire to secure by Letters temperature of the charge, and introducing manganese at intervalsafter'the commence- .6 ment ofihe tions during the blow to control the oxida: tion of the charge.

In testimony whereof I have signed my name to this specification in" the presence of two subscribing witnesses.

- RQBE'RT A. HADFIELD. Witnesses:

A. G. 'lnvls.

LUTHER J. Plum.

blow,-,a nd continuing such addi-" v