US1213973A - Alloy roll-steel. - Google Patents

Description

FRANK D. TAG-GART, OF WYOMISSING, PENNSYLVANIA.

ALLOY ROLL-STEEL.

No Drawing.

To all whom it may concern Be it known that I, FRANK D. TAGGART, a citizen of the United States, residing at \Vyomissing, in the county of Berks and State of Pennsylvania, have invented certain new and useful Improvements in Alloy Roll-Steel, of which the following is a specification.-

My object is to provide an improved alloy steel adapted particularly for the manufacture of rolls used in shaping steel bars and plates of various sections.

Rolls having a moderate percentage of 1 carbon, as from .40 to 1.15, and also of nickel in some cases, are frequently employed in the earlier rolling processes, while chill rolls are generally used in the final finishing processes; the former possessing the strength requisite for roughly reducing the ingots and billets or slabs to approximately the sectional form desired, while the latter possess the smooth hardened surface required for the finishing passes, though lacking in requisite strength to withstand the shocks and strains incident to the roughing passes, and also liable to develop objectionable and weakening surface cracks.

My purpose is to provide a special alloy steel adapted for the production of rolls having all the requisite rolling qualities in high degree, to wit: rigidity and strength to insure against both distortion and breakage under the shocks and strains incident to satisfactory reduction in the passes; and homogeneity and surface hardness to insure against surface cracks and wear; the resulting effects being a maximum of quantity and quality production, and economy of mainte nance.

My improved alloy steel contains the following elements in about the percentages stated, to wit:

Garbon 1.60 Chromium 2.25% Vanadium; 25% Iron 95.00% Silicon, manganese, &c .90%

Specification of Letters Patent. Pafientefi Jan, .3349, 1911 Application filed October 31, 1916. Serial No. 128,696.

The minor elements silicon, manganese, sulfur, and phosphorus, may be present in the quantities incidentally found in ordinary steels; and the contents of the stated essential elements may be varied within certain limits without materially changing the essential characteristics of my improved alloy steel: the carbon between 1.25 per cent. and 2.50 per cent., the chromium between 1.50 per cent. and 2.50 per cent., with the vanadium remaining at approximately .25 per cent. or sufficient to secure a hard homogeneous structure.

Rolls cast of this improved. alloy steel show, when cold, a scleroscopic hardness of 55 to 65 about equal to that of chill rolls as commonly employed. This hardness, which extends through the homogeneous sectional structure, together with desired heat-resisting andshock-absorbing qualities, is imparted by the carbon, chromium, and vanadium elements combined as stated, and a far stronger roll than the usual chill roll of like diameter and length is produced; the yielding points for both compression and tension being so high as to insure great rigidity, though the elasticity is suflicient to insure against breakage under possible undue strains. The hardness is such as to prevent objectionable Wear, and is secured without liability to service cracks; so that a maximum length of service, as well as a maximum product output, is attained by employing my improved material in the manufacture of these rolls. 1

What I claim is:

The improved alloy roll-steel described, composed mainly of iron, with percentages of carbon between 1.25 and 2.50, of chromium between 1.50 and 3.00, and of vanadium approximately .25; the minor elements present not exceeding one per cent.

In testimony whereof I afiix my signature.

FRANK D. TAGGART.