US1245552A - Alloy. - Google Patents

Description

UNITED sTATEs PATENT oFFio FREDERICK M. BECKET, 0F NIAGARA FALLS, NEW,YORK, ASSIG-NOR TO ELECTED METLIJLURGICAL COMPANY, OF NIAGARA FALLS, NEW YORK, A CORPORATION or WEST vmemra No Drawing.

To all whom it may concern:

Be it known that I, FREDERICK M. BEOKET, a subject of the King of England, residing at Niagara Falls, in the county of Niagara and State of New York, have invented certain new and useful Improvements in Alloys, of which the following is a specification. v

This invention is a new alloy containing as essential components iron, chromium, carbon and usually silicon, and distinguished.

Chromium 25 30 Carbon 1.5- 3 Silicon 0.0- 3 Iron 73 63. 5% usuall with traces of manganese, sulfur,

phosp orus, copper, and perhaps otherelements.

To a lesser, although still marked de ee,

7 this combination of qualities is foun in alloys outside of the range above indicated. For example, alloys containing as low as 20 per cent. and as high as 35 per cent. of chromium, the carbon and silicon being approximately as specified above, are serviceable for many of the purposes mentioned below.

The extreme toughness and hardness of the above-mentioned alloys render them highly e1ficient and desirable substitutes for chllled shot and crushed steelin the cutting and grinding of marble, granite and the like; and moreover, their freedom from tendency to oxidize or rust in presence of water presents the advantage that there is no liability to staining the stone. stance, it is well known that crushed steel cannot be used for marble-grinding where freedomfrcm staining is of importance;

whereas the present alloys are eminently suited for this use, in addition tabemg ca- Speciflcation of Letters Patent.

For in Armor.

Patented Nov. 6, 19 17.

Application filed April 10, 1916; Serial No. 90,208.

,pable of much more rapid cutting or grinding. The degree of resistance to rusting is dependent in a measure upon the silicon-content of the alloy, being more strongly marked as the silicon-content is increased within the limits specified. If however the silicon-content exceeds these limits a tendency to brittleness is observed.

As an illustration of resistance to oxida-- tion at high temperatures, a cast bar of alloy containing chromium 28%, carbon 2.72%, sllicon 0.40%, the balance practically all iron, was exposed continuously at 1100 C; Y

for two weeks to an oxidizing atmosphere in an electrically heated 'mufie furnace without undergoing appreciable oxidation, whereas a mild steel underidentical condi tions was quickly converted into scale oxid.

'Alloys within the limits above specified possess a strongly marked fibrous structure. They can be forged. and machined, although with difiiculty as compared with ordinaw steel. They can be annea-led'and also tern pered, and in general are responsive to heat treatment, although to a materially less degree than ordinary high-carbon steels.

Among the uses to which the possession of the above-mentioned properties render the new alloys particularly adapted are mentioned the following 1) As an abrasive. For example the molten alloy may be poured into water in order to granulate it, and the resulting granules crushed by stamping or otherwise, and graded, therebv producing irregularly shaped cutting grains or particles of approximately uniform size. The abrasive particles may be used as substitutes for chilled shot or crushed steel in the grinding and cutting of marble and granite as mentioned above, or they may be bonded by a silicate or other bond into abrasive wheels or other implements, the firing being carried out under ordinary conditlons, in case a silicate bond is used. (2) In the form of cast articles where extreme hardness and toughness are required, as for exam le crusher jaws, stamp shoes, balls and linings for ball-mills, and in general for the wearing parts of milling'and grindin machinery.

(3) a non-slipping surface 1n conjunction with cements, artificial stone com,-

(4) For the blades of steam turbines, where the highest degree of resistance to wear and oxidation is required.

(5) For cutting tools.

(6) For high-temperature applications, especially under oxidizing conditions, as for example exposed parts of annealing and peaking ovens, crucibles, furnaces and the The herein-described alloys may be prepared by various methods, as for example by melting commercial grades of high-carbon ferrochromium with the requisite proportion of steel scrap in a crucible furnace, adding if necessary silicon or ferrosilicon. The composition of the component materials being known, the proportions of such ma serials required to produce an alloy of any desired composition is easily mxnputed arithmetically.

I claim 1. An alloy characterized by a high. de

gree of hardness, toughness and resistance to oxidation, and containing" chromium 20 to 35 per cent, carbon 1.5 to 3 per cent, and

to per cent, carbon 1.5 to 3 per cent., and

silicon 0.0 to 3 pally iron.

3. A tough per cent., the balance princiand substantially non-oxidizalole casting composed of an alloy contain ing chromium 20 to per cent, carbon 1.5 to 3 per cent, and silicon 0.0 to 3 per cent, the balance principally iron.

4. A tough and substantially non-oxidizable casting composed of an alloy containing chromium 25 to 30 per cent, carbon 1.5

to 3 per cent, and silicon 0.0 to 3 per cent,

the balance principally iron.

lin testimony whereof 1E aifix my signature in presence of two witnesses.

FREDERIGK M.

Witnesses MARY Scam, SIDNEY Gris.