US2012765A - Alloy steel, chiefly for use in the manufacture of railroad parts, rails, and the like - Google Patents

Description

Aug- 27, 1935. P. P. MARTHOUREY ALLOY STEEL, CHIEFLY FOR USE IN THE MANUFACTURE v OF RAILROAD PARTS, RAILS AND THE LIKE Filed July 5, 1952 Patented Aug. 27, 1935 d l 2,012,765 y UNITED STATES PATENT oFF-ICE ALLOY STEEL, CHIEFLY FOR USE I N THE MANUFACTURE F RAILROAD PARTS, RAILS, AND THE LIKE Paul Pierre MarthoureyfAsnieres, France, assignor to Acieries De Gennevilliers, Gennevilliers, France, a corporation of France Application July 5, 1932, Serial No. 620,933

France December 11, 1928 y Claims. (Cl. 148-31) My present specification is a continuation in asimple or double heating above its transformapart of my prior specification Ser. No. 411,993 tion point followed if required by a quenching in flied on December 5, 1929. It has for its object quiet or agitated air, in water or in oil and if a self-quenching alloy steel the chief property required by one or more further heatings under- 5 of which is that of being adapted for use when neath the point of transformation or even in 5 cast after it has received a suitable thermic treatsome cases, above it.

ment. This treatment has for its effect an in- By wayof example, I will give hereinafter two crease in the resistance to wear and to strains examples of this heat treatment. whereby it may be used in the same manner as Example I.-The heat treatment consists of: steels of somewhat similarv composition which (a) A first heating above the point of trans- 10 have under-gone forging or rolling. formation and underneath about 1250" C., fol- Thls heat treatment provides a metal at least lowed by a suitable cooling; as satisfactory as the commonly used wrought (b) A second heating above the point of transhard steel. formation and underneath about 1100 C, fol- 'I'he steel according to my invention may thus lowed by a cooling in air; 15 be used after casting for any kind of construc- (c) A third-.heating underneath the point of tional parts which are to resist wear or strain, transformation and above about 150 C., followed such as rails, railroad or tramway tracks, racks, by asuitable cooling. gear wheels, parts for naval construction and the Example II .-fIhe heat treatment consists of:

like. Heretofore only certain steels having high (a) A. first heat treatment above the point of 20 contents of manganese have been adapted for transformation and underneath about 1250" C., such uses when cast. Such steels show many followed byacooling in air;

drawbacks amongst which I may mention 'a low (b) A second heat treatment above the point elastic limit, a small resistance to repeated shocks of transformation and underneath about 1000"- and the impossibility of being machined when C., followed by a slow cooling in the furnace. 25 cold or of being welded through an alumino- A cast steel thus treated may show a very large thermic or electric method. Moreover these range of lcharacteristic properties as disclosed steels with high contents of manganese cannot hereinbelow with referencev to accompanying be hated as they are not stable when submitted drawing wherein:

to variations in temperature. Fig. `1 is a side view with an inset cross-section 30 The alloy steel according to my invention has of a test used for tractional tests.l the following composition: Figs. 2 and 2a show respectively in side view i and in cross-section a test piece of the so-called gg g Eg (Zhi/Z Mesnager type used for resiliency tests. Nickel 2 to 517 Figs.A 3 and 3a show respectively in View from 35 o above and in cross-section along line I II-III of Molybdenum 0,1 to 1% M Fig. 3 a special test piece used for strain tests.

olybdenum tungsten 0,1to1,5% F1 4 h i t t ,Manganese 0,2m 1% g. s ows in side v ew a es piece for tests under repeated hammer blows. Silicon 0,1 to 0,5% Figs. 5 and 5aare respectively a side view and 40 Vanadium 0 to 0,5%.

a cross-section of a test piece used for wear tests. Titanium 0 to(),5%

A test piece for tractional tests (Fig. l) is con- Alumimum 0 l000.1% tit ted b l. d 1 od I di ith t Copper o 2.5% S u y a cym nca r en ng w wo thicker parts 2 which are to be held in the jaws Phosphorus and Sulphur-""as little as possible of the testing machine. A Mesnager test piece 45 e. g. phosphorus 0,035% (about) and for resiliency tests (Figs. 2 and 2a) `is constituted smphur oo15% (about) by a rod 3 provided with a notch 4 in its midle I u, Non metallic inclusions "as lime as possible and the ends of which bear on supports 5. The The method of preparation should reduce these test consists in measuring the work required for non metallic inclusions toamlnimum,sothat the the shock due to a drop weight acting on the 50 cast steel may be clean and well decanted and middle of the bar on the side opposed to the thereby free from earthy,i. e.-non metallic innotch to cause the breaking of the bar. The test clusions,'before it is cast in a mould. piece used for strain tests (Figs. 3 and 3a) is con- The heat treatment capable of giving this cast stituted by a railroad crossing 6 with hollow steel the desired properties consists preferably of grooves. Metal cakes l of small diameter are placed on the points and are submitted to hammering; In Fig. 4 is shown a test piece for tests under repeated hammer blows in a machine ot the Cambridge type, said test piece comprising a rod l grooved at 9. Lastly Figs. 5 and 5a show a test piece to be used for wear tests in a machine of the Amsler type, said test piece being constituted by a washer of the metal to be tested.

Tractional tests effected on the test piece shown in Fig. 1. l

Resistance about 75 to 180 kgs. per sq. mm. Elastic limit about 50 to 160 kgs. per sq. mm. Elongation for 100 mm. lengthabout 5 to 16% Elongation for 50 mm. length about 8 to 22% Striction about 15 to 50% Hardness test Brinell hardness about 200 to 600 Resiliency test on a M esnager test piece shown in Fig. 2

At ordinary temperature and after remaining a certain time at 20/25 C 5 to 14 kilogrammeters (about) At ordinary temperature after four hours between about 475 and 525 C 4 to 13 kilogrammeters (about) At a temperature of about 500 C. (about 450 to 525 C.) 4 to 12 kilogrammeters (about) with the interposition of a plate or punch of small diameter.,

The metal supports 100,000 shocks without any noticeable crushing, without any cracks and without scaling.

Repeated hammer shock tests on the test piece shown in Fig. 4 in a machine of the Cambridge type at the frequency of 1 blow per second )with a hammer weighing 2 kgs. 320 falling through a height of 40 mm.

The metal resists about 10,000 to 25,000 blows' according to the treatment and to the superheating of the metal.

Wear tests in a machine of the Amsler type, using test pieces such as shown in Fig. 5, the metal according to the invention rubbing on wrought steel of 90 kgs. resistance with a pressure of 100 kgs. at a speed of rotation of 200 to 220 R.. P. M. the machine being adjusted for hammering and sliding.

After 110,000 revolutions the loss in weight through wear of the metal according to invention is 0.275 grams and the loss in diameter is T31, of a millimeter.

As to the strain characteristics, I may state for instance that my improved steel shows a resistance against repeated shocks which is on the average about times above that of the commonly used basic steel tested under the same conditions.

Moreover the metal is very stable when the temperature varies and its mechanical characteristics and in particular its resistance to shocks are sutllciently constant. They remain substantially unaltered after remaining along time at any temperature between about -20 C. and +525 C.

It will be remarked that these temperatures and more particularly. those between 450 and 1525" C. generally produce brittleness in the case of the usual nickel and chromium containing -than that of the above mentioned basic steel.

The special composition of my improved steel allows the application to certain portions particularly subjected to wear of a further hardening heat treatment which modifies the metallographic texture through a certain thickness and which, by reason of the nature of the steel to which it is applied, does not produce like the superficial cementation treatment applied to known steels,

, any heterogeneity in the metal which would cause breaking up and scaling.

This local hardening treatment consists of one or more rapid heatings above the point of transformation up to about 1200" C. Such heatings do not decarburize and burn the metal provided they are effected say by means vof the oxyacetylene blow-pipe.

This local treatment may be followed by aircooling and if required by heating underneath the point of transformation, which steps may, if desired be performed throughout the mass of the steel parts.

I obtain thus throughout a. thickness of about 0 to,30 mm. a Brinell hardness reaching to about 600 and a minimum resiliency of about 3 kgms. for a Mesnager test piece, even in the case of a metal superheated considerably above its point of transformation.

What I claim is:

1. A self-hardening steel for rails and railroad apparatus comprising 0.2 to 0.5% of carbon, 0.6 to 2% of chromium, 2 to 5% vof' nickel, 0.1 to 1.5% of molybdenum plus tungsten including 0.1 to 1% of molybdenum, 0.2 to 1% of manganese, 0.1 to 0.5% of silicon, less than 0.035% of phosphorus, less than 0.015% sulphur and the balance substantially iron, said steel having been heated at least once above the transformation point and belowy 1210 C. and air cooled without an mechanical treatment.

A2. A self-hardening steel for rails and railroad apparatus comprising 0.2 to 0.5% of carbon, 0.6 to 2% of chromium, 2 to 5% of nickel, 0.1 to 1.5% of molybdenum plus tungsten including 0.1 to 1% of molybdenum, 0.2 to 1% of manganese, '0.1 to 0.5% of silicon, less than 0.035% of phosphorus, less than 0.015% of sulphur, vanadium up to 0.5% and the balance substantially iron, said steel having been heated at least once above the transformation point and below 1250 C. and air cooled without any mechanical treatment.

3. A self-hardening steel for rails and railroad apparatus comprising 0.2 to 0.5% oi' carbon, 0.6 to 2% of chromium, 2 to 5% oi' nickel, 0.1 to 1.5%

of molybdenum plus tungsten including 0.1 to 1% of molybdenum, 0.2 to 1% of manganese, 0.1 to

5. A self-hardening steel for rails and railroad 0.5% of silicon, less than 0.035% of phosphorus, less than 0.015% of sulphur, titanium up to 0.5% and the balance substantially iron, said steel having been heated at least once above the transformation point and below 1250" C. and air cooled without any mechanical treatment.

4. A self-hardening steel for rails and railroad apparatus comprising 0.2 to 0.5% ot carbon, 0.6 to 2% of chromium, 2 to 5% of nickel, 0.1 to 1.5% of molybdenum plus tungsten including 0.1 to 1% of molybdenum., 0.2 to 1% o! manganese, 0.1 to 0.5% of silicon, less than 0.035% of phosphorus, less than 0.015% of sulphur, aluminium up to 0.1% and the balance substantially iron, said steel having been heated at least once above the transformation point and below 1250 C. and air cooled without any mechanical treatment.

apparatus comprising 0.2 to 0.5% of carbon, 0.6 to 2% o! chromium. 2 to 5% of nickel, 0.1 to 1.5% of molybdenum plus tungsten including 0.1 to 1% of molybdenum., 0.2 to 1% of manganese, 0.1 to 0.5% of silicon, less than 0.035% of phosphorus, less than 0.015% of sulphur, and material taken from a group and within the limit mentioned consisting of vanadium up to 0.5%, titanium up to 0.5%.- aluminium up to 0.1% and the balance 'substantiauy iron, said steel having been heated at least once above the transformation point and below 12.50 C. and air cooled without any mechanical treatment.

PAUL PIERRE MARTHOUREY.

CERTIFICATE OF CORRECTION.

Patent N0. 2,012,765. August 2'?, 1935.

PAUL PIERRE MARTHOUREY.

It is hereby certified that error appears' in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 58,v claim l for "belowy l210" read below l250; and for "an" read any; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office y Signed and sealed this 10th day of March, A. D. 1936.

Leslie Frazer (Seal) Acting Commissioner of Patents.

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