US1572458A - Alloy steel - Google Patents

Description

Patented Feb. t), 1926. j

UNITED STATES v p 1,572,458} PATENT OFFICE...

,WILLIAM r. woonsrnn AND CHARLES Newman DA'WE, on Der-norm. mrcnrenn, assmnons TO THE STUDEBAKER CORPORATION, or scorn BEND, INDIANA, A con,-

ronArIon on NEW JERSEY.

.ALLOY STEEL.

No Drawing;

To all whom it may concern:

Be it known that we, WILL AM P. ,Woon- SIDE and CHARLEs NEUMAN DAWE, citizens of the United'States of America, and residents of Detroit, in the county of Wayne and Stateof Michigan, have invented certain new and useful Improvements in Alloy Steel, of which the following is a specification.

This invention relates to an alloy steel,

more particularly designed for use in the I manufacture of articles requiring a tough elastic core, and a hard outer surface adapted to form a hearing or Wearing surface, such 'aspins, bolts, gears, bearings and other ma-' l5 chine parts.

Such articlesare usually made from What is lrn'own as low carbon steel, that is, steel or alloy steel having such a low carbon content that heating and guenching does not 29 harden it to a material egree, itilieing necessary to carburize the surface b well lmown methods and then to proper y heat and quench the same to obtain the desired surface hardness; the core, not having been carburized, remaining relatively soft.

. -Heretofore, the steels available for such use have beensuch that the desired uniform hardness of the surfacecould only'be obtained by heating, after'carbonization, to the proper degree, and then quenching in water instead of oil. The great and-very'im ortant disadvantage of quenching such articles in"water is that while the desired hardness I may be obtained, the surface isvery brittle, ,whereas .it'is desirable that the surface be hard and at the same time tough and relatively elastic. 'Such articles as pins and the like invariably warp in the operation of quenching, whether the quenching agent be water or oil, and it is necessa to straighten them before grinding the sur ace tofinished dimensions. Such articles quenched in water,

are-so brittle that a relatively large percentage are brokenin the straightening operation, and further, a. relatively large percentage of those successfull straightened have to be scrapped due to c ecks developin in their surface during the subsequent in ing operation, dueto the excessive britt eness of the surface. The surface of such. articles quenched in oil are not brittle but are tou h :1 and elastic. The hardness. obtained tofore available steels or alloy steels, in oil,

per cent of the entire metal.

Application filed August 24, 1923. serial No. 859,213.

has been so low that is considered preferable to obtain the desired surface. hardness by quenching in water at the expense of the relatively large resulting percentage of scrap.

The object of our present invention is to provide an alloy steel that may be used for the manufacture of such articles, and which after having been properly carburized,

heated and quenched in 011 will have a sur,

face hardness comparable with such articles made of the steels heretofore available and quenched in water, which because of their toughness and elasticity, may be straightened bent With little, if any, breakages, and

operation of grinding. Another object is to provide such an alloy steel that will be capable of production on a commercial scale and at a cost conunensurate with the cost of Our invention consists in a new alloy steel I having substantially or approximately the 1 usual carbon and manganese content of mild steel and in addition; thereto and alloyed therewith nickel preferably in the proportion of about 1.40 per cent to about 1.75 per cent and molybdenum, preferably in the pro portion of about .20 per cent to about .30

The metal of our invention may and ordinarily does con tain the usual small percentages of sulphur and phosphorus found in mild or low carbon steels. r

Analyses of specimens of our improved alloy steel have shown compositions within the following limits: Carbon, .10.% to 23%;

manganese, 30% to .60%; sulphur, .06%

max.; phosphorus,'.04=% max.; nickel, 1.40% to 1.75%; molybdenum, 20% to 30%; iron, 97.02% to 98.00%. I

We'prefer to maintain the composition as to the essential elements within the limits a slight ex:

cess or deficiency of any oft thecomposition would not involve a substantial change. in thecharacterof the steel and i i would be within our invention.

In-v the following claims the reference'to' y mild steel is to be understood as implying i quenching these articles, made from the bores the presence of carbon and man anose m about the proportions in. which t eycomthey havea uniform surface sclerosco e.

monly occur in mild or low carbon steel,

such as is commonly employed for. the pur-' pose referred to above.

This allo steel ma", forged, mac inedand the like, its characteristics during such operations being approximately. the same as in nickel steels having the same nickel content. The strength is approximately the same as other alloy steels havin the same heat treatment, which is in the neighborhood of 30% greater than ordi-' nary steel of the same'carbon content.

We have found that this alloy steel particularly lends itself .to themanufacture of ,parts to be machined from hot rolled or cold drawn bars, such as shack1e-bolts, tie-rod bolts, worms, piston-pins and the like. These parts do not require heat treatment before the carburizing operation, and .when heated, after having been carburized, from 1475 to 1500 degrees Fahrenheit and quenched in oil,

hardness after grinding of 75 to 85. s before stated, no steel has been available heretofore for such uses as described, which would give this uniform surface hardness. by

quenching'in oil. Not only is the surface ofarticles made from this alloy steel quenched in oil as hard as described above, but the sur-.

face, while being ofsuch a hardness, is tough and elastic, cracks but very little. due to bending or straightening and is not so sus ceptible to the development of surface checks in the operation of grinding as in alloy steelsheretofore used.- It is therefore a particularly desirable alloy steel for. use in the manufacture of such'articles.

Having thus described-our invention, What we claim is:

1. An alloy metal composed .of .10% .to

23% of carbon, .30% to .60% of manganese,

be readily rolled,

1.40% to 1.75% of nickel, 20% 01302, of molybdenum and 97% to 98.1% of iron. I

2. An alloy steel having .10% to 23% of carbon, 30% to -.60% of manganese, 1.00%

to 2.00% of nickel, and 15% to .30% of molybdenum.

3. A mild steel containing as alloying metals in addition to manganese substantial amounts of nickel and molybdenum only, each of these metals being present in substantial proportions and the entire content I 1.7 5 per cent of nickel.

' 6. A mildgsteel containing about .20 per cent to about .30 per cent of molybdenum anda larger ercentage of nickel, the entire content of a1 oying metal not substantially exceeding 2.66 per cent.

7 A mild steel containing substantial amounts of nickel. and molybdenum, the

nickel being in excess, of the molybdenum and the entire content of alloy metals not being substantiallyin excess of 2.66 per cent.

8. A mild steel containing from about 20 per cent to about .30 per cent of molybdenum and a larger percentage of nickel, the entire per cent. Signed by us at Detroit, Michigan, U. S. A.

this 20th day of August, 1923. I

WILLIAM P. WOODSIDE. o. .NEUMAN DAWE.

amount of alloying metals not substantially exceedin 2.66