US1844284A - Railway track crossing and the like - Google Patents

Description

Feb. 9, 1932. v. c. HONSTAIN 1,844,284

RAILWAY TRACK CROSING AND THE LIKE Filed Feb. 16, 1951 I INVENTQR VERNON 6. Hows-mm jFJ-VQ aw A T'TOHNE Y5 Patented Feb. 9, 1932 nites srArEs VERNON G. HONSTAIN, OF MINNEAPOLIS, MINNESOTA RAILWAY TRACK CROSSING AND THE LIKE Application filed February 16, 1931. Serial No. 515,955.

factors present a serious problem to manufacturers of special track work and it is the general object of the present invention, to offer a solution of this problem.

By special track work I mean such parts as crossings, frogs and the like which, in use, are required to possess characters of strength, hardness. wear resisting qualities and adaptability to welding. Such parts, asnow manufactured and installed, do not possess these requisites and, among other things, lack adaptability to welding of the character most useful in this type of work, namely the so called thermit welding.

It is the object of the present invention to provide a section of special track work, such as a crossing frog, of cast alloyed steel which possesses the necessary characteristics of strength, hardness and wear resisting qualities and which is particularly adapted for thermit welding.

I have chosen for the purpose of illustration a right angle crossing frog but it is to be understood that this is only one example of the several types of special track construction to which my invention relates. I have, therefore, shown in the single figure of the appended drawing, more or less diagrammatically, a right angle crossing frog which, except for the nature of the alloy of which it is made and the manner of welding it to the ends of the rails, is of standard construction and configuration.

In the said drawing the reference numeral 1 indicates a crossing frog including arms 2, 2 which are welded as at 3, 3 to the ends 4 of the adjacent rail sections.

The crossing frog 1 is made of a special alloyed steel having approximately the following formula:

Carbon 25% to 35% Chromium 1.25 to 1.75% Molybdenum .25 to .35 Nickel .50

Silicon .25 to .35 Manganese .7 5 to 85% Phosphorous and sulphur Iron remainder of alloy.

The foregoing materials are melted together in the usual manner until the resultant mixture is in condition for pouring. Any well-known method of ployed to produce castings of desired shape and size from the foregoing mixture and, when complete, the castings are subjected to special heat treatment. V

F or inserts intrackwork, usually small pieces, the castings, having first been made, are heated to a temperature of about 17 50 F. At this point the heat treatment is interrupted and the casting is allowed to cool, after .04 and under which it is reheated ata temperature of about 1650 F., whereupon the casting is quenched in air. The draw may be made for desired hardness, as will be well understood.

For larger pieces, such as the crossingfrog shown in the drawing, a difierent heat treatment is followed. Castings of this type are heated for a period of about four hours to a temperature of about 1650 F. and then quenched in air until black. Thereupon the casting is covered with sand, ashes or lime and is allowed to cool for a period of five to six hours.

The addition of molybdenum to the alloy about the same proportion heretofore specified makes air quenching practical because of the greater penetration and, thus, the expensive oil quench so generally practiced is eliminated.

Castings of the character herein described casting may be emlend themselves readily to thermit welding which, as is well-known, is a type of welding in which an aluminum-iron oxide mixture is used and fused at high temperature. I have discovered that thermit welding does not seriously affect the properties and characteristics of steel castings made in accordance with the foregoing description and that in fact the grain structure at or adjacent to the weld is very similar to the grain structure at apoint remote from the weld.

A test piece has been made in accordance with my invention and the results of the tests to which it has been subjected indicate that a casting of my invention possesses all the desirable properties heretofore described. The test piece was welded by thermit welding to the ends of open hearth steel rails and subjected to breaking tests and hardness tests and, thereafter, to metallographic analysis. The breaking test resulted in a slow break remote from the weld which showed a cupped silky fracture characteristic of ductile steel. The fact that the fracture did not occur at the weld indicates that the welded portion was, at least, of the same strength as the remainder of the casting; v

The hardness test showed uniform hardness throughout the casting, the Brinnell 2 number being substantially he same throughout the length of the test piece although slightly lower than the Brinnell number for the adjacent sections of the open hearti steel rail. This difference in hardness may be eliminated by slightly increasing the carbon content of my alloy to produce the desired degree of hardness.

Metallographic analysis was made of the test piece, the weld and the adjacent section of the open hearth steel rail. Micro-examination showed a somewhat coarser grain structure of the casting adj acent the weld than at molybdenum, and capable of being united by thermit welding to adjacent steel rail sections.

3. A railway track crossing and the like special track work comprising a casting made of a steel alloy containing substantially from 1.25% to 1.75% of chromium and from to of molybdenum.

4. A railway track crossing and the like special track Work comprising a casting made of a steel alloy containing substantially from 25% to 35% of carbon, from 1.25% to 1.75% of chromium, from 25% to .'35% of molybdenum, of nickel, from 25% to 35% of silicon, from .7 5% to of manganese and 04% or less of phosphorus and sulphur.

5. In a section of railway trackage, railway track crossing and the like special track work comprising a casting made of a steel alloy containing substantially from 1.25% to 1.75% of chromium and from 25% to 35% of molybdenum, and a plurality of open hearth steel rails joined to said casting by thermit welding;

6;""In a section of railway trackage, a rail- {way track crossing and the like special track work, comprising a casting of a steel alloy I containing substantially from 25% to 35% of carbon, from 1.25% to 1.75% of chromium, froin25% to 35% of molybdenum, 50% of nickel, from 25% to 35% of silicon, from .7 5% to .85% of manganese, and 04% or less of phosphorus and sulphur, and a plurality V of open hearth steel rails joined to said casting by thermit welding. v 1

In witness whereof, I have hereunto set my hand this 14th day of February, 1931. r VERNON G. HONSTA IN parts remote therefrom but, with this exception, it was proved that the weld did not affect the casting. Also, there was a very marked resemblance between the structure of the weld and of the casting, thus, indicating a satisfactory weld.

An alloyed steel casting such as that herein described possesses all the requisites of hardness and strength and, in addition, the adaptability to thermit welding without injurious effects, which make these castings ideally suited for special track work.

I claim as my invention:

1. A railway track crossing and the like special track work comprising a casting of a steel alloy capable of being united to adjacent steel rail sections by thermit welding without material changein the grain structure of said casting.

2. A railway track crossing and the like special track work comprising a casting made of a steel alloy containing chromium and

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