US1914102A - Ferrous alloy - Google Patents

Description

Patented June 13, 1933 UNITED STATES PATENT orFics RALPH L. BINNEY, OF TOLEDO, OHIO, ASBIGNOB TO THE BINNEY CASTINGS COMPANY,

OF TOLEDO, OHIO, A CORPORATION OF OHIO FERROUS ALLOY 1T0 Drawing. Application filled Kay 20,

This invention relates to a ferrous alloy having great resistance to deterioration when subjected alternately to elevated and low temperatures, and also having a high resistance to scaling, cracking, and warping at high temperatures. 1

The alloy, in addition to iron and carbon contains aluminum, silicon, chromium, 'and vanadium. a

The alloy has a tensile strength of approximately 45000 pounds per square inch, which is about twice that of ordinary cast iron. Its hardness is also about twice that of ordinary cast iron, the alloy having a Brinell hardness of about 325. Although the alloy has a hardness and strength approximately double that of ordinary cast iron, its machinability does not differ greatly from ordinary cast iron, and for this reason it can be used where cast iron has been employed formerly, but where it is desired that the alloy be able to withstand alternateheating and cooling and also withstand high temperatures without substantial deformation. Its expansion upon heating is slightly less than cast iron and it has less permanent growth. a Y t The alloy is exceedingly fine grained and takes a better polish than cast iron, due to its denser nature. Softening does not occur at temperatures above 1300 .F., which temperature is higher than is necessary to produce softening in ordinary cast iron. Even at a temperature of 1500 F., the hardness of the alloy is about 255 Brinell. Due .to the fact that the alloy retains its hardness and strength at temperatures of 1500 F. or above, the alloy is unusually well suited for making glass molds where these properties enable the material to retain edges that do not break off or pean down. The marked ability of the alloy to resist tempering or softenin at elevated temperatures makes it extreme y valuable for use under conditions where strength and hardness are required while an alloy is very hot.

The alloy is particularly adapted for molds for forming glass and parts of glass equipment coming in contact with molten lass or urnace equipment, valves for internal combustion 1881. Serial No. 688,875.

engines, molds for die-casting machines, and for any uses requiring a metal having greater strength or hardness than cast iron, or where the article must withstand high temperatures or alternate heating and cooling with- 56 out substantial scaling, cracking, warping or deformation.

The-ferrous allo having these properties contains carbon about 2.5% to 3.5%, aluminum about 2.0% to 3.5%, silicon about 00 2.0% to 3.5%, chromium about 2.0% to 3.5%, and about .10% to .50% of-vanadium. The alloy may also contain sulphur, phosphorous and manganese in small amounts as impurities, but for best results neither the sulphur nor the phosphorus should exceed 04%, and the manganese should not exceed 20%.

I also havefound that when the aluminium, silicon, and chromium contents of the alloy are each about 3%, the desirable physical properties and resistance to scalin and crackmg appear to be at a maximum. preferred analysis of the alloy is about 2.80% carbon, about 3% aluminum, about 3% silicon, about 3% chromium, and about .17% vanadium.

The alloy is well adapted for nitriding, and for certain purposes where a hard wearresisting surface is desired, it is advisable to nitride the alloy. Any of the usual nitriding processes may be employed for this purpose.

preferred to form the alloy by melting It is in a crucible. It may, however, be made by any of the common methods of making cast iron, but an inferior product results. In carrying out the preferred crucible melting method, a pure IIOII containing carbon, but containing only small amounts of impurities such as sulphur, phosphorous and manganese, is melted in the crucible. It is preferred to use as the iron forming the base of the alloy, the metal known commercially as washed metal, since this washed metal is substantially free from impurities and contains practically only iron and carbon. Less satisfactory results mav be obtained, however, by using other types of iron as the base metal. The necessary amounts of aluminum, silicon, chromium and'vanadium to produce an alloy. having the analyses above stated is added to 1 the washed metal, anu the meltin is controlled so as to given rlting car on content of 2.5 to 3.5%. lit is preferrefi that the ferrous base, for example washed metal, contain not over 04% of phosphorus or sulphur, anu not over 20% of manganese.

- I have flescribecl indetail one method of reducing my alloy. lit is to be unuerstoodl, however, that the alloy may be produced by Ether methods and that the alloy 18 not limiteol the following claimis.

I claim:

warping at high temperatures, and contaming about 2.5% to 3.5% carbon, about 2.0% to aluminum, about 2.0% con, about 2.0% to 3.5% chromium, 10% substantially iron.

2. A ferrous alloy resistant to scalinganfi. warping at high temperatures, and contain ing about 2.5% to 3.5% carbon, about 2.0% to 3.5% aluminum, 2.0% to 3.5% silicon, about 2.0% to 3.5% chrominum, anol'about .l0% to 25% vanadiium, the balance being substantially iron.

3. A ferrous alloy resistant to scaling ancl warping at high temperatures, and; containing about 3.0% carbon, about 3.0% aluminum, about 3.0% slicon, about 3.0% chromium, andl about .10% to .50% vanadium;, the balance being substantially iron.

and about In testimony whereof I have hereunto set my hanu. RALPH L. BINNEY.

antenna the analysis givenin the specific embodiment, but may be varied within the scope of l. A ferrous alloy resistant to scaling a d Q to 3.5% silito Vanadium, the balance being