US1860852A - Ferrous alloys - Google Patents

Description

TES

=1 NIT 1 iii.

HENRY L. COLES, OF HAMILTON, OHIO, ASSIGNOR TO GUARDIAN METALQ COIVCPANY, 0F HAMILTON, OHIO, A CORPORATION OF DELAWARE FERROUS ALLOYS No Drawing.

ture and require special precautions in the preparation of the various alloys thereof and in the fabrication of articles prepared therefrom.

It is an object of the present invention to provide an improved ferrous alloy having a high degree of hardness and torch resistance.

It is also an object of this invention to provide an improved ferrous alloy containing substantial amounts of manganese, chromium and carbon.

Another object of this invention is to provide an improved composition comprising major amounts of iron and substantial amounts of combined manganese, chromium, and carbon.

These, and other desirable objects and advantages of the present invention will be described in the accompanying specification, certain preferred compositions being disclosed by way of example only, for, since the improvements of the present invention may be comprehended in other specific compositions, it is not intended to be herein limited to the ones set forth as examples except as such limitations are clearly imposed by the appended claims.

In one of the desired practical embodiments the improved alloy of the present invention preferably comprises substantially 15 to 18 per cent manganese, 7 to 15 per cent chromium, 2.2 to 3 percent carbon, and the remainder iron. While these percentages have been set forth as determinative of the preferred range of the compositions included in this invention, it will, of course, be understood that variations in the amounts of the several components may be made without de- Application filed March 22, 1930. Serial No. 438,232.

parting from the spirit and scope of this invention. As exemplifying specific compositions which have been found to give desirable results, the following are noted:

No. 1?!) 3i g 12?:

All of the alloys above described have a scratch hardness of substantially 7.4 to 9 on Mohs scale, and are markedly torch-resistant and drill resistant.

While a'preferred range of compositions has been disclosed, the invention comprehends alloys included within varying percentages, as follows:

Manganese 13 to 20 per cent Chromium 3'00 18 per cent Carbon 2 to 4 per cent Iron 82 to 61 per cent Ferroinanganese 3 to 2 per cent Ferrochromium 16 to 12 per cent When using scrap from the castings made' -from the above, the following preparations were found to be satisfactory:

Spiegel pig 46 to 57 per cent Ferromanganese 1 to 2 per cent Ferrochromium 6 to 11 per cent Alloy scrap 47' to 30 percent The analysis for manganese, chromium and carbon in the rawrma-terlals used is as follows:

Ferromanganese 8.4 per cent manganese 4.65 per cent carbon Ferrochromium 80.3 per cent chromium 1.49 per cent carbon Spiegeleisen .20.11 per cent manganese 2.97 per cent carbon It is preferred to employ the rocking in-' direct-arcelectric furnace in the prepara-. tion of these improved alloys. One desired purpose for using this ty of furnace is to substantially eliminate t e burning out of manganese from the composition as well as to insure homogeneity of the resulting product. Y The metal, after melting, is preferably allowed to set in the ladlw until it becomes substantially quiet; It is then poured into molds which are preferably pre-heated. This pouring is usuall done rapidly and the castings are allowe to cool slowly for a desired period to prevent cracking. This cooling may even extend for twenty-four hours. One method of accomplishing the desired cooling is to ram up the molds with an excess thickness of sand to thereby retard the dissipation of heat from the casting. Such regulated cooling acts to equalize the stresses normally set up in the castlng.

It will 'now be appreciated that there has beendescribed novel ferrous alloy compositions having relatively high manganese and g5 chromium contents, together witha high carbon content, and which. are characterized by a very marked degree of torch and drill re sistance.

It will be particularly noted from the fore- 80 going description that the improved allo -described herein accomplishes in a muc more eflicient manner the heat resistance and drill resistance desired. Further, these advantages are obtained by an alloy which is 85 very much reduced in cost of manufacture, and gives many advantages not obtained in some of the other alloys. This improved alloy is capable of many uses, es ecially where it is desired to employ materialwhlch will 40 readily withstand heat and is especially resistant to the action of drills and other destructive implements.

The im roved alloy herein set forth and described lsdefined as an example, and it is desired that any modifications or changes therein shall be considered as being within the scope of this invention as'outlined' in the following claims.

What is claimed is: I 1. A. hard alloy comprising 14 to about 7 18% manganese, 7 to 9.03% chromium, about 2 to 4% carbon and the balance iron.

2. A hard alloy comprising about 16.5% manganese, about 9.03% chromium, about 2.19% carbon and the balance iron.

3. A hard alloy com rising about 18% manganese, about 7. 5 0 chromium, about 2.76% carbon, and the balance iron. 4. A hardalloy comprising about 16 to- 00 18% manganese, about 8 to less than 9% chromium, and abor 2 to 3.5% carbon and thergalance iit'ion.

y 's speci cation si ed this 21 da of March, 1930. gn y as HENRY L. COLES;