US1085488A - Steel. - Google Patents

Description

prise the mparting to steel,

MAINE.

UNITED STATES PATENT orrros.

AUGUSTE J. 3058!, OF NIAGARA FALLS, NEW YORK, ASSIGNOB TO THE TITANIUM ALLOY IANUFACTUBING COIPANY, OF NEW YORK, N. Y., A CORPORATION OF STEEL.

coloration of Letters Intent.

Patented Jan. 27.. 191-1.

Ho Drawing. Original application filed January 6, 1911, lerial Ho. $301,161. Divided and this application filed April 25, 1912.

To all whom. it. may concern:

Be it known that I, Aocosra J. Rossr, a citizen of the United States, and a resident of Niagara Falls, in the county of Niagara and State of New York, have invented certain new and useful Improvements in Steel, of which the following 18 a specification, my present application ,bein a division .of my copending application erial No. 601,161 filed J anuaty 6, 1911, on which were granted to me Letters Patent No. 1,028,389, dated June '4, 1912.

The objects of my present invention comparticularly rails em )loyed in railroad construction as the bearing surface for locomotives, motors, and rolling stock, not only greater hardness than heretofore, but also at the same time greater endurance-and reater capacity to resist shock and vibrations, and l attain these objects by the productof the methods of treatment hereina ter described. For examdple, the resent requirements specified as in ispensab e in rails of the ty referred to embrace the atest possible ardness or ca acity to resist frictional wear, and not on y this but the greatest possible endurance so called, being the capacity to endure, without undue disintegration, repeated momentary shocks under high pressures in various directions, and also the capacity to resist the disintegrating effects imparted by vibration. Hitherto it has been well understood that hardness is imparted to such rails substantially proportionately to their content of carbon, but the desired increase of said content has proved im ossible beyond certain comparatively low imits even by resort to addition of certain percentages of manganese, say about 1% or less, notwithstanding which additions, or even greater additlons, of manganese, it has nevertheless still proved impossible, in practice, to incorporate more than say 0.5% to 0.0% of carbon without imparting prohibitory brittleness. The presence of the manganese, u to a certain point, a pears to overcome t e brittleness nnparte by the carbon to the extent of permitting the rail to be rolled successfully, and, without the said addition of manganese in sufficient amount, rail material contninin as high as the aforesaid 0.5% and 0.6% 0 carbon has proved. impossible to be rolled. It appears however to be understood at pres- Serlal No. 893,207.

ent that said use of manganese imparts to the product some undesirable qualities as for instance probably retention therein of sulfid ofnmnganese, to which has been attributed evil efi'ects. Moreover, as above implied, the employment of manganese for this specific purpose is limited, manganese being unable to counteract suflicient-ly the brittleness imparted by the carbon in bi her than the above stated percentages. y researches have demonstrated that by the presence of titanium in lieu of manganese for the specific purpose for which the latter has been employed as aforesaid, not only is the brittleness attributable to, I may say, unlimited increase of carbon perfectly controllable, it being thus possible -to dispense entirely with manganese for the purpose stated, but also that the titanium, in proper amounts, is capable of imparting to the resulting rail having substantially any desired content of carbon, not only increase elastic limit, elongation and ultimate strength, as hitherto understood to result from purifying action of titanium, but also, and articularly as I have recently demonstrated, certain a ditional roperties and characteristics satisfying tie present requirements in rails as above stated, -to .wit, unprecedented hardness and also endurance and capacity to resist vibration. I believe these last mentioned characteristics of the rail embodyin titanium to be due in part to the combined presence therein of the said high percentages of carbon and a suilicient amount of titanium to overcome the brittleness imparted b such carbon contents. At all events it will )0 understood that the superior capacity of the rail to resist successfully attrition is due in part to the presence of the high percentage of carbon admissible by my treatment, whereas, on the other hand, this characteristic. would, however, desirable, prove'impracticable, for rolling and otherwise, without the presence of the titanium,,that is to say its novel effect when coacting with more than 0.6% of carbon upon the structure of the steel, as for instance the groupings of its ferrite, pearlite and cementite, which results in overcoming its otherwise prohibitory brittleness and imparting thereto, in addition to hardness, the endurance and resistance to vibration referred to.

It will be understood that my present ingranted to me August 23,

vcntion comprises not only the im rovement of steel, generally speaking,b ad ing thereto wlnle molten a quantity 0 titanium s'ufiicient to chemically combine with undesired elements and compounds resent and thus insure a resulting product ree from such impurities comprising slags and containin also substantially no, or traces onl o titanium whereby certain highly desirable characteristics are imparted due to the complete purification of the metal, such being lucreased elastic limit, elongation and ultimate strength. On the contrary my present invention comprises not only the improvement of the metal by purification referred to, but also, and particularly, in addition to this the imparting to steel rails for example of qualities unattainable by the said purification merely, and the accomplishment of this novel resu t by means of increasin the carbon content of said rails to any egree desired above the, sa 0.6% hitherto practicable, and by ad itions of titanium not onl suflicient to purify the metal as aforesai but also to insure retention in the final product of an amount of titanium sufiicient, in combination with said carbon, to impart the increased hardness and also the increased endurance and resistance to vibration which it is my object to secure. My present invention is practised as follows: Po the molten steel from which the rails are to be ultimately rolled, said steel containing the desired high percentage of carbon, i. a. above 0.6%, e. g. as hi h as 0.85%, or as much higher as required, add a relatively small quantity of metallic titanium, preferabl in the form of the alloy of that metal with iron known as ferrotitanium, which may be produced for instance as per Letters Patent No. 609,460

1898. The sai amount of titanium is, pro ortioned tosatisfy the chemical afiinities 0 previously ascertained undesired elements and compounds contained in or absorbed by the steel and thus sccure'their removal, including slaigs, by the process for which Letters Patent 0. l,003,805, were ranted to me on September 10, 1911. In t is instance however I also intentionally add to the said amount of titanium so ascertained enoifgh additional titanium to insure the retention in the final product, after the titanium has performed its aforesaid purifying function, of a certain amount of that metal 2'. e. enough to imart to the final product such endurance and resistance to vibration as is required to overcome completely the otherwise prohibitory brittleness to be expected from t e presence of the particular content of carbon em loyed. Anything in excess of the amount 0 titanium thus specified will rove not only a waste of the metal for t e particular purpose in hand, but also, in some cases, possibly deleterious as imparting characteristics 5 and qualities as yet undetermined and which are likely to prove of decided disadvantage in steel rails. It will be apparent that the aggre to amount of titanium thus added to the stee as aforesaid will depend upon the particular requirements of each case as determined not only by knowledge of thecharacter and extent of the impurities contained in the steel but also upon t e percentage of carbon employed, and furthermore upon tests of specimens of each type of steel treated to determine the amount of titanium required in the final product to insure, notwithstanding the high carbon content, absence of brittleness and such endurance and resistance to vibration as may be required.

I prefer to introduce the titanium in the form of its alloy with a ferro-metal as aforesaid, the said alloycontaining from 10 to 12% or thereabout of metallic titanium. In some instances I have found that as little as one-third of 1% of the said alloy last mentioned is suflicient to insurers; its chemical combination with undesi elements and compounds entire removal of the latter including slugs, and that in such instances in which the steel treated contained as high as 0.85% of carbon the further addition of from of 1% to 1% of the said allo has proved sufiicient to ow ercome all britt eness attributable to said 0.85% carbon and also to impart to the resulting rails qualities of endurance and resistance to vibration hitherto I believe unattained and otherwise unattainable. For example in one instance in which the carbon content of the steel was 0.85% I added thereto while molten altogether about 1% to 1 1% of my alloy of titanium with iron, ferro-titanium containing 10 to 12% of titanium. The rails from this steel rolled perfectly, and under the vibration test withstood over sixt million vibrations without impairment; a so on the breaking'test the said rails proved very superior under the severest strains, forinstsnce between sup-' ports five feet apartendurin several central impacts of a ton weight alling thereon 14 to 16 feet, whereas the tests for hardness disclosed that the surfaces of said-rails were from 200 to 300 per cent. harder, than the pgeviously best approved so-called hard carn rails analyzmg'at 0.50%- to 060% carbon, 0.85% manganese and 0.10% silicon.

I refrain from specifying more fully the method of adding the ferro-titanium to the steel bath as this is already well understood in the art. The bath being maintained at the melting point of steel, the titanium so introduced in alloy with ferro-metal dissolves therein promptl and erforms its functions on the ineta and i impurities as'aforesaid. Recent microscopic and other tests have demonstrated that the effect of the residual titanium introduced as per-my feature of my present invention as aforesaid is a parently to change in important and bone cial particulars the structure of the steel as regards extent of ferrite and cementite and also pearlite and their grou ings relatively to each other and likewise tliat in presence of the high percentages of carbon stated an exceeding? small amount of residual titan ium is su cient to accomplish these results, the residual titanium content of the steel rails so treated by my present process being less than 1%.

While the beneficial result of my novel method appears attributable to the combined effect of a high percentage of carbon with a small percenta of titaniuin in the resulting product, may also in some cases employ with said high percentages of carbon and low percentages of titanium characterizing my present invention a small amount of manganese but very much less than formerly required to overcome brittleness imparted by a much lower than 0.50% carbon content. For example in some instances I have thus added man ncse so as to have in' the final rail pro uct not to exceed 0.60% to 0.18% of manganese. In fact in some special types of steel the presence of a thus minute content of manganese" as compared with that formerly used an indispensable, is of advantage for special purposes, or to satisfy special requirements other than actual prevention of carbon-imparted brittleness.

I am aware that heretofore titanium, eithcrby itself, or, more usually, in combination with other elements hostile to my present purpose, has been retained 'in final steel products for the purpose of roducing what are now well known in t e art as alloyed steels, 1'. e. steels which owe their distinguishing properties chiefly to the presence of a thereto added and therein retained element, or elements, other than carbon. But on the contrary, a distinguishing resent invention is the au mentation of t e carbon content, in steo l, beyond that previously deemed practicable by aid of manganese and this for the purpose of imparting to the final product, in proportionally higher degree than heretofore, distin ishing properties due to presence of hig percentages of carbon, my addition and retention of titanium in such product thou h containing, for other purposes, much ess manganese than suflicient to overcome brittleness, bein in aid of such augmentation of carbon, an for the specific purpose of ov'ercoming the hitherto proihitory brittleness thereby imparted notwithstanding any content of manganese, and such retention of titanium being sufficient in amount to accomplish my said purpose, but insuilicient to justify designation of the roduct as a titanium alloyed steel, t e resulting product being also characterized as being steel unassociated with metals other than titanium and manganese. I am aware that, prior to my present application for patent, an alloy has been described as consisting of. steel containing from .10 er cent to .60 per cent of carbon, and nicke 1.00 to 5.0 parts, manganese .25 to .7 parts, and titanium .50 to 10.0 parts, in which the nickel is employed to impart toughness to the alloy, and the emp o ment of manganese is absolutely essentia Neither said alloy, nor the method of producing it, constitutes any part of my present invention, which. latter, as above stated, aims at overcoming byaid of titanium only, or of titanium and less manganese than would be otherwise required, the undesired brittleness imparted by greater than 0.6% carbon contents, and thus secure desired toughness without dependance on nickel.

What I claim as new and desire to secure by Letters Patent is the following,

1. As a new article of manufacture, steel characterized as containing titanium, also more than 0.60% carbon and as being unalloyed with other metals.

2. As a new article of manufacture,'steel characterized as containing less than 0.50%

titanium, also more than 0.60% carbon and as being unalloyed with other metals.

3. As a new article of manufacture, steel characterized as containing titanium, also more than 0.60% carbon, also manganese and as being unallo ed with other metals.

4. As a new article of manufacture, steel characterized as containing less than 0.50% titanium, also more than 0.60% carbon, also manganese, and as being unalloyed with other metals. p

5. As a new article of manufacture, steel characterized as containing titanium, also carbon above one er cent.

6. As a new article of manufacture, steel characterized as containing titanium not to exceed one er ceht., also carbon above 0.60 per cent, a so manganese not to exceed 0.60

.per cent. and as unalloyed with other metals.

7 As a new article of manufacture, steel characterized as containing carbon over one per cent., also titanium and manganese.

AUGUSTE J. ROSSI.

Witnesses:

. Wauraa D. EDMQNDS,

Pmmr C. Peon.

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