US1285749A - Steel rail. - Google Patents

Description

I M mar/WM? R. A. LEWIS, w. R. SHIMER & w.1. THOMAS.

S- EEEEEEE L.

I APPLICATION FILED MAY 15. !95. 1 ,285 ,749. Patented Nov. 26, 1918.

STEEL RAIL.

" To all whom it may concern:

Be it known that we, Roy A. Lnwrs, WIL- LIAM ROBERT SHIMER, and WILLIAM J. THOMAS, all citizens of the United States, and residents of Bethlehem, Northampton county, Pennsylvania, have jointly invented new and useful Improvements in Steel Balls, of which the following is a specification, reference being had to the accompanying drawings, in which The figure of the drawing shows .a sectlon of a rail illustrating the microstructure of a rail embodying our invention, magnified 100 diameters.

Our invention relates to steel rails, and

consists particularly in a rail containing less than .90% carbon, 1.00% manganese, and with silicon, sulfur and phosphorus in the percentages usually found in open hearth rail steel, and having a high tensile strength,

a high elastic limit, an elongation, a reduc-v tlon in area, and a hardness under the Brinell'tests much greater than is found in an untreated rail of the same composition.

Typical examples of rails embodying our invention, containing, (1) .61%' carbon, '.68'% manganese; (2) .71%' carbon, .76% manganese, and with silicon, sulfur and phosphorus in the percentages usually found in rail steel, treated in accordance with our have given the following results in comparison with untreated rails of the same composition:

7 (1.) .61% carbon, .68% manganese.

s Treated. Untreated.

Tensile stren hpers in 130 000 lbs.- 107 500 lbs. Elastic limit if sq. ni 801 000 541000 Elongation 17.5% 15.0 Reduction in area 43. 3% 24. 08% Brinell hardness No 245 214 (2.) .71 carbon, .7675 manganese.

V Treated. Untreated. Tensile strength per sq. in 138, 000 lbs. 120,000 lbs. Elastic limit per sq. in 88,000 66,000 Elongation 19. 5% 13.5% Reduction in area 48. 8% 22. 3% Brinell hardness No 260 227 Specification of Letters Patent. Application filed May 15, 1915. Serial No. 28,282.

Patented Nov. 26, 1918.

the treated steel showing the following increases over the untreated steel:

S eoimen lie. 1.

Specimen N o. 2.

. Tensile strength per sq. in Elastic limit per sq. in Elongation Reductionin area Brinell hardness In both instances the treated steel shows much greater strength and higher elastic limit, and is much more ductile, although coniiderably harder, than the untreated stee Untreated specimen No. 1, an 80-pound rail, supported on anvils spaced 3 feet apart, under a 2,000-pound weight, falling from a height of eighteen feet, stood four blows be fore breaking, and the total deflection, meas ured from the points of support, was 5.90 inches, the total elongation (in six inches taken along the exterior of the deflected portion of therail) was 1.31 inches, and the fracture was coarse and crystalline.

Treated specimen No. 1, of-the same section and mounted in the same way-as the untreated specimen, stood six blows before breaking, with a total deflection of 8 inches, and a total elongation (in six inches taken along the exterior of the deflected portion of the rail) of 1.77 inches. The fracture was fine and fibrous.

Untreated" specimen No. 2, a 100-pound rail, supported on anvils s need 3 feet apart, under a 2,000-pound weig t, falling from a height of twenty-three feet, stood four blows before breaking, and the total deflection, measured from the points of support, was 7 inches, the total elongation (in six inches taken along the exterior of the deflected portion ofthe rail) was .71 inches, and the fracture was coarse and crystalline.

Treated specimen No. 2, of the same section and mounted in the same way as the untreated specimen, stood seven blows without breaking, further blows being impossile on account of the limitation of testing machine, the total deflection was 11 inches, and a total elongation (in six inches taken along the exterior of the deflected portion of the rail) of 1.06 inches. It. was subsequently fractured and the fracture was found to be fine and fibrous.

\Ve prefer to produce a rail having the characteristics above described, by taking a rail as it comes from the finishing rolls and the hot saw, cooling it in an air spray to a temperature well below the critical point, and thereafter re-heating the rail to a temperature above the critical point, and preferably between 1100 and 1500 F. When the rail has been heated so that all of its parts are of uniform temperature, we then remove it from the furnace and introduce it into a bath of oil or other cooling medium, so as to cool it very quickly, and thereby preserve as much as is possible the solid solution of iron and carbon in which condition the rail is when heated to above the calescence point. The rail is cooled to between 500 and 1000 F., and is then introduced into an annealing furnace, in which it is heated to between 1000 and 1250 F., and is retained in the annealing furn'ace until all of its parts have reached. a uniform temperature. It is then withdrawn and allowed to cool.

The completed rail has a microstructure of fine, granular pearlite and is almost free from free ferrite. The free ferrite found in the rail is uniformly disseminated in small particles throughout its section, as is shown in the figure of the drawings. It contains between .60%.90% carbon, .50%1.00% manganese, and sulfur, silicon and phosphorus in the percentages usually contained in rail steel. It has a tensile strength of approximately between 115,000 155,000 lbs. per square inch; an elastic limit of approximately between 70,000 and 95,000 lbs. per square inch; an elongation of approximately between 15%25% (in 2 inches): a reduction in area of approximately between 30%55%, and a hardness Copies of this patent may be obtained for five cents each, by addressing the by the Brinell test of approximately between 225 and 325.

Rails made in accordance with our invention are found not only to have a greater tensile strength and elastic limit than untreated rails of the same composition, but they also have a much greater ductility and hardness, thus greatly increasing the life of the rail when made in accordance with our invention.

The terms and expressions which we have employed are used as terms of description and not of limitation, tention, in the use of such terms and expressions, of excluding any equivalent for the features which we have described, but recognize that various modifications are possible within the scope of the invention claimed.

What we claim is:

1. A steel rail having a microstructure of fine granular pearlite, and being almost free from free ferrite, containing approximately between .60% to .90% carbon, .50% to 1.00% manganese, and with sulfur, silicon and phosphorus in the usual percentages found inopen hearth rail steel, and having a tensile strength of over 115,000 lbs. per square inch, an elastic limit of over 70,000 lbs. per square inch, an elongation of over 15%, a reduction in area. of over 30%, and a hardness by the Brinell test of over 225.

2. A steel rail containing approximately between .60%.90% carbon, .50%1.00% manganese, and sulfur, silicon and phosphorus in the usual percentages found in open hearth rail steel, and having a tensile strength of approximately, between 115,000 and 155,000 lbs. per square inch, an elastic limit of approximately between 70,000 and 95,000 lbs. per square inch, an elongation of approximately between 15% and 25%, a reduction in area of approximately between 30% and and a hardness by the Brinell test of approximately between 225 and 325.

' BOY A. LEWIS.

W. ROBERT SHIMER. WILLIAM J THOMAS.

Commissioner of Batents,

Washington, 20. G,

and we have no in;

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