US1511111A - Composite railway-track member - Google Patents

Description

Patented Oct. 7, 1924.

v UNITED .STATES PATENT, OFFICE.

JAMES H. cnrrcnnrr, or BAYSIDE, NEW YORK. ASSIGNOR T THE OXWELD nun .1 Roan SERVICE COMPANY, A conronn'rron or DELAWARE COMPOSITE RAILWAY-TRACK -IMEMBER AND COMPOSITION FOR, JPROIDUCING T HE a SAME.

No Drawing. Application fi led July29, 1922, Serial No. 578,499. Renewed September 8, 1924.

T 0 all whom it may concem.

Be it known that I, JAMES H. CRITCHETI,

a citizen of the United States, residin at Bayside, in the county of Queens and tate of New York, have invented certain new and useful Improvements in Composite Railway-Track Members-and Compositions for Producing the Same, of which the following is aspecification.

This invention relates to composite railway track members having a body portion of one composition, which is at least in part cased, sheathed or armored With another composition'of greater hardness and higher resistance to wear. The invention also comprises novelcompositions useful for 'producing casings or armor of'the kind men-. tioned on track members and other members subjected to similar service.v V

The material for railway rails, frogs, switches and crossings, should have the strength and toughness necessary in struc-v tural members together with eat hardness and resistance to wear to ena le it to withstand the abrasion and pounding to which it is subjected by the rolling stock. No single material has been found which combines these qualities with suflicient cheapness and workability, and a fairly high carbon steel has been universally adopted as a compromise. While surface deterioration necessitates expensive replacements, failure of the body of the rail by fracture is'apt to cause disastrous accidents. For

I 85 this reason the carbon content has been limited to prevent any dangerous brittleness and the great majority of rail troubles are a matter of mere surface deterioration.

I Several expedients have been proposed for 40 producing composite track members having body and surface portions particularly adapted to their respective special requirements. The restoration of wearing surfaces Which had been more or less damaged, by 4 providing a new surface of a material particularly fitted to withstand surface wear,

I has been of much interest, and thepossibility of filling in or building up the worn surfaces with a suitable metal fused by the electric are or by the blow-torch has attracted special attention. The present inventionrelates to processes of-this nature. For .the sake of brevity, metal which is deposited in molten form on a member for the purpose described will be referred to as added metal, while the material of the member which receives such addition will be termed the base metal.

Steel of higher carbon content than the body of' the rail has been tried as added metal, but the increased carbon makes its deposition in homogeneous form a diflicult matter. Furthermore, in carbon steels, the brittleness increases with hardness, so that While deterioration by deformation or abrasion may be reduced, deterioration by spawlin-g, chipping and cracking becomes a serious objection. I

It has also been proposed to usea manganese steel containing, say, 14% of manganese for such purposes. This also has not proved entirely satisfactory, for while manganese steel is highly resistant to wear under certain conditions, a heat-treatment is necessary to develop this property and if the appropriate heat-treatment is applied to the added manganese steel, the body of the rail, being carbon steel, is rendered dangerously brittle. Furthermore, manganese steel is not hard enough to resist in a wholly satisfactory manner such impacts as certain kinds of track members receive. Another difficulty experienced when manganese steel is used as the added metal is explained by the fact that steels containing certain percentages of manganese, less than the manganese content of the added material, have properties which render them unfit for use in any part of a rail. or the like, and these undesired compositions may be formed at the junctureof the added and base metals, due to dilution of the manganesecontent of the added metal by the superficially fused base.

'I have found that a better casing or armoring material for worn or new track members or the like may be produced by using chromium as a hardening agent in the v steel added, a considerable amount of carbon being also incorporated. The chromium content should preferably be not much below 1.0% and may be increased to 3.0% or more. The carbon content may be as much as 1.0%, but it is preferred to keep the carbon at a considerably lower figure and to secure the necessary hardness and toughness by suitable additions of chromium. F urthermore, I have found that a reciprocal relation between the carbon and chromium ios percentages gives thebest results, this relation being sufiiciently illustrated by the following examples:

lit themaximum chromium addition (about 3%) is used, the carbon should pref- 'erably not exceed 0.5%; while if the carbon is as low as 0.2%, the chromium content should be between1.5-3.0%. With a carbon content approaching the maximum (for example 1%), the chromium should preterably not exceed 1.5%. My preferred chromium range is from .75% to 1.50% with carbon between 0.2% and 0.6%.

y 1 also find it desirable to include a considerable quantity of silicon in the metal which is tobe melted andbuilt up on the in welding operations. The manganese content of the welding metal may be from .50%

to 1.75% and the silicon from .3%' to 1.50%. Excellent results have been obtained with manganese between .80% and 1.0%, and sili-' con between'.50% and .75%. In general, a part of the manganese. will persist in the filled-in metal, where it probably has a favorable action as an alloyed constituent.

The best results appear to be obtained when the percentage of manganese is somewhat greater than the percentage of silicon, for example, approximately in the ratio'of 1.5

' or 2 to 1.

A filling metal having carbon 0.35% to 0.415%, chromium 1.0% to 1.2%, silicon 0.5%

to 0.6% and manganese 0.9% to 1.1%, has

given excellent results.

The chromium-containing compositions disclosed herein produce a case or armor which in hardness, toughness, and resistance to wear, excels the carbon steel base on which it is laid. The added metal is free from the brittleness of carbon steels of comparable hardness, and is very much easier to manipulate. The chromium compositions are harder than the manganese steels which have been used for similar purposes, and therefore are less deformed by impact. They require no heat-treatment and form no compositions of undesirable properties with the base'metal.

While various specific compositions are described herein for purposes of illustration, it will be understood that the invention is subject to many modifications in accordance with the principles disclosed, and is only limited by the appended claims.

Welding rods or the like comprising alloys of the type disclosed herein are described and claimed in .my application Serial No. 690,089, filed February 1, 1924;.

ll claim:

1. A railwaytrack member comprising a steel base armored'with an alloy steel which,

without heat-treatment, is harder and more resistant to wear than said steel base.

2. The invention according to claim 1 in which the alloy steel of the armor contains a substantial amount of chromium.

8. The invention accordingto claim 1 in which the alloy steel of the armor contains a substantial amount of chromium, less than 3%.

4. The invention according to claim 1 in which the alloy steel of the armor contains between 0.75% and 1.50% of chromium and between 0.2% and 0.6% of carbon.

In testimony whereof,-l afiix my signature.