US1830747A - Mechanical product and method of producing the same - Google Patents

Description

Nov. 10, 1931. N. BRAY 0,

MECHANICAL PRODUCT AND METHOD OF PRODUCING THE sum Filed May 15. 1929 v fil'ggj V Arronnzx;

Patented Nov. l0, 1931 NELSON H. BRAY, OF SAN FRANCISCO, CALIFORNIA MECHANICAL PRODUCT AND METHOD OF PRODUCING THE SAME Application filed May 15, 1929. Serial No. 363,366.

This invention relates to a mechanical prodnot and the method of producing the same. The primary object of the invention is to reduce frictional wear and compression by mechanically imbedding particles of metal having a high degree of hardness, into the body of metals having a lesser degree of hardness,

whereby the metal with the lesser degree of.

hardness presents a surface with a high degree of hardness to frictional attrition or other wear.

This invention is particularly applicable to the hardening of the abutted ends of railroad rails, the heads of which pound down by the passage of the traction wheels thereover, making a depression at each joint where the ends abut. It is equally applicable to the points of cams, the ends of valve stems and tappets, valve seats and other such surfaces where wear is concentrated, and adapted to be fortified by the introduction of a harder material, in accordance with this invention.

Other objects and advantages will appear as this description progresses.

In this specification and the accompanying drawings the invention is illustrated in the form considered to be the best, but I do not wish to be understood as confining it to this form because it may be embodied in other forms, and it is also to be understood that in and by the claims following the description it is desired to cover the invention in whatsoever form it may be embodied.

In the'accompanying one sheet of drawings Fig. 1 is a side elevation of the abutted ends of two railroad rails and a fragmentary portion of a car wheel resting thereupon, diagrammatically illustrating one use of the invention. One of the rails is shown partially 40 in cross-section disclosing the hard particles imbedded therein, in accordance with this invention. Fig. 2is a plan view of a fra ment of adhesive paper coated with partic es of hard material, illustrating one convenient way of applying the hard material to the bod of material into which it is to be imbedde In detail the product and the method of producing the same as illustrated in the drawings, referring to Fig. 1, comprises the rails 1 and 2 joined by the h plates 3 between two of which the abutting ends are clamped by transverse bolts in the usual manner. The car wheel 4 is shown resting upon one rail end that has been treated in accordance with this invention as shown in cross-section. The adjoining rail end 2 has resting thereupon a piece of paper 5 coated with the hardened particles 6, that will be driven into the softer steel of the rail by the passage of the car wheel 4 thereover. Railroad rails are composed of what is commercially known as high point carbon steel, the hardness of which is calculated to best meet the demands of traflic passing thereover. Because of the danger of fracture, additional costs and other considerations, it is manifestly impractical to make a rail of steel of a degree of hardness that will reduce wear to the minimum throughout its length. On the other hand the quality of steel that best meets the major demand of the length of the rail fails to present a degree of hardness at the abutting ends, which because of their ductilit flatten under the con .stant hammering of t e car wheel A eventually causing a depression at the abutting ends. The disruptive effect of which on railroad stock is well known, as well as the fati ing effect upon the metal of the rail itsel It is present practice to meet this situation by locally hardening the rail ends by means of so the acetylene torch and hardening compounds; or to electrically fuse spots of hard steel. on the surface by using one end'of a welding rod in a electric arc. Both these processes are expensive and cumbersome and the latter method requires subsequent grind= ing to level the surface of the rail after treat ment. Thehardening and spotting of the rail as described is a temporary expedient not permanently effective because of the hardening in one instance and the deposited metal in the other are not as hard as the imbedded additions incorporated by the present inven tion. 1

There is at present available on the market an alloy known as stellite composed a"? chrc mium, cobalt, tungsten and other materials, combined by a secretv process. The chromium; and cobalt appear to act as a matrix for the harder tungsten carbide in the alloy. Such mg l alloys have a degree of hardness approaching that of a diamond or above that o commercial carbon steels such as used in railroad rails and the like. Such alloys have the fur- 5 ther advantages of being non-corrosive, nonmagnetic, breaking into very shar well defined crystals, and will withstand t e pounding necessary to imbed them into the softer steel of the rails without fracturing. While such. alloys are sufficiently hard they are also to a limited degree ductile and will flatten out and form a very desirable surface upon the relatively softer steel into which they are imbedded.

In the practice of this invention, old rail ends that are already pounded down below their normal traction plane at the joints or elsewhere throu hout their lengths, may be built up by im edding therein these hard alloys in relatively larger particles, so that a portion of the imbedded article will stand above the surrounding sur ace to the desired extent. Where new rails or the like are to be treated it is advisable to use finer articles for imbedding into the surface, t at will quickly drive'down flush with the operating surface of the rail. \Vhere the points of cams and similar operative mechanisms are reinforced by imbedding these alloys into the body of the cam, the procedure is to hammer or press theparticles of alloy into the body of the metal to be reinforced, then grinding the same by abrasive wheels down to the operating surface desired, in the usual manner, leaving the exposed surfaces of the alloy particles flush with the surrounding surface of the operative part.

The affinity of chromium for ferrous alloys is well known. In the practice of this invention it has been found alloys similar to stellite imbedded in steel appear to establish a chemical bond therewith, it being observed that when they are dislodged, they bring with them particles of the steel into which they were previously imbedded, which particles of steel adhere to the particles of alloy. This latter effect has not as yet been proved by exhaustive tests but appears to be a phenomenon attendant upon the practice of this my invention. Particles of harder steel imbedded into the relatively softer steel upon being dislodged do not ap ear to act in this manner. Furthermore, suc steel particles driven into steel become minutely fractured and set up an electrolytic or corrosive action or rust when exposed to the atmos here. They become disrupted or dislodge from the space into which they are imbedded. This latter disadvantage is not true of the chromium alloys. When embedded in the baser metals they retain their own integrity and do not seem to set up the disruptive chemical action between themselves and the baser metal, as above described between the different quali- 65 ties in steel, thus making a permanent reinforcing addition to the wearing surface of the baser metal beneath.

Having thus described this invention what I claim and desire to secure by Letters Patcut is:

,, sure.

3. A rail having the wearing surface thereof reinforced by embedding a hardalloy com prising stellite therein.

4. A rail having the wearing surface thereof reinforced by embedding particles of a hard alloy at normal temperatures therein by the pressure of rolling stock passing there over. 1

5. A rail having the wearing surface thereof reinforced by embedding particles of stellite therein by the pressure of rolling stock passing thereover.

6. A rail having portions thereof reinforced by adding to said portions a hard alloy under pressure at normal temperatures.

- 7. A rail having portions thereof reinforced by adding to said portions stellite under pressure.

8. A rail having the surface thereof reinforced by stellite embedded therein.

9. A metal product having an alloy of chromium, cobalt and tungsten embedded therein by a process carried out under rela tively low temperatures.

10. A hard ferrous metal product having a tungsten carbide alloy embedded in a surface thereof so as to reinforce said surface while at the same time retaining the tensile strength of the ferrous metal.

11. A steel product having embedded in a surface thereof granular particles of an alloy containing chromium, cobalt and tungsten.

12. A steel product having a surface thereof reinforced by the embedding therein of particles of a hard matrix containing tungsten carbide.

13. A steel product havinga portion thereofreinforced by embedding therein particles of a harder substance having such an afiinity for said steel as to be retained in said steel when said steel is subjected to severe strain and variations of temperature.

14. A steel product having a surface thereof reinforced by embedding therein particles of a hard matrix having such an afiinity for ferrous alloys as to remain fixed therein under variations of temperature and pressure and containing particles harder than said matrix and said steel.

15. A steel product having embedded an alloy havin a higher de e of hardness and ductility t an said stee '16. A metal product havin upon a surface thereof a film of a hard a y. 1 17. A steel product having upon a surface thereof a. film of a harder material.

18. A metal product having upon a surface thereof a film of stellite 19. A rail having upon the wearing surface thereof a film of stellite.

In testimony whereof I have hereunto afiixed my signature.

NELSON H. BRAY.

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