US2854331A - Alloys and alloy articles - Google Patents

Description

Sept. 30, 1958 R. s. ROSE ALLOYS AND ALLOY ARTICLES Filed 001;. 26. 1956 Stainless M 0 0| 3 n e al 5 g n u T T M u g e R 5 4 fl ofx .2: $2

INVENTOR Robert 5. Rose Heat LiQnmTiK- iiZLfiL 5.565006656567767 699039046750511 089688692113760 RYOJ RWFQQWKQL 333333344QQ4444 Percent Percent tion Z mAFmQWQmGWA QA A LAImQ 112112111122221 Reduction of Area R. L. Elonga- (hrs) 5 Ono-0912224833182 Percent Percent gatlon Patented Sept. 30, 1958 TABLE 11 TABLE III R. L. E1on- (hrs) improvement is evident upon study of the Stress rupture properties are among the most important for aircraft gas turbine and compressor application. Table II sets forththe rupture strength, elongation and reduction of area of this new composition. For com- Rupture strength of modified tungsten stainless iron arison Table III gives values for the base alloy. The

P substantlal data.

stantially improved hardness and stress-rupture properties 10 at elevated temperature without any impairment of ductility.

erties at elevated temperatures while at the same time a n w a P S e t na t S d e t 1 H U nwnnnnawo 989998999 0 5 2 2 anl a ham V.

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Rupture strength of regular tungsten stainless iron Samples treated 2000 F., oil quenched Temper 1200 F. HardnessRockwell C 34 C about .10%-.25% plus an amount equal to 10% of the amount of columbium present Mn less than about 1.5%

Si less than about 1.5%

Fe balance with usual impurities in ordinary amounts.

Preferably, I limit the alloy to a somewhat narrower range as follows:

W about 2.75%-3.25%

Ni about 1.75%2.25% 35 Cr about 12.5%13.5%

Cb about .30%-.40%

C about .l2%.20% plus an amount equal to 10% of O 5 4 4 ea mwn mk kymw m uT n d HCM f .m m m dvme a m m .mmms

e eem 61 r fin r P .U o e r SC h m m m P Ht .m m meA 1D .l hOu 00 Wha m flt nu numw w C u mf t e un hlfbO bwuuim b m w m mm u n 66 3 e In ac u d mthn ty as a u .dsfl aa .m mbfipu 3. MfiF mga To enable a direct comparison of three variables: rupture strength, time, and temperature, on a two dimensional chart, a stress parameter formula has been used.

50 Samples treated 1850 F., oil quenched Temper 1100" F. Hardness-R0ckwell C 34 Where:

25 is a constant for 12% chrome alloys T is absolute temperature F. t is time The significant increase in elevated temperature properties is clearly obvious in the figure. This figure is a comparison of the stress-parameter of a regular tungsten stainless and an alloy according to the present invention. Comparisons along verticals 39 and 40 show a 20% improvement in stress-parameter for the new discovery. While I have set forth certain preferred compositions and alloy articles of this invention in the foregoing Hardness-Rockwell O Prior condition: annealed As Quenched material: /2" thick discs.

All samples were austenitized by holding at the indicated temperature 30 minutes, then oil quenching-all tempers were of 2 hours duration] MODIFIED TUNGSTEN STAINLESS IRON ture, F.

Heat treating modified and regular tungsten stainless iron Austenitizing Tempera- REGULAR TUNGSTEN STAINLESS IRON specification, it will be understood that this invention may be otherwise embodied within the scope of the following "claims;

I claim:

1. A ferrous alloy of high hardness and stress-rupture properties at" elevated temperatures comprising 1 about .10%' to? .25% carbon plus an amount of carbon equal to 10% ofthecolumbium present, about 10% to- 17% chromium, from 1% to.5%' tungsten, about .75% to 2.75% nickel, about .3%' to 1% columbium, less than about 1.5% manganese; less than'about'1;5% silicon and substantially iron with residual impurities in ordinary amounts, said article beingcharacterized by a high degree of hardness and high stress-rupture properties at elevated temperatures along with a high degree of ductility.

3. A ferrous alloy of high hardness and stress-rupture properties at elevated temperatures comprising about .12%

4. to 20% carbon plus an amount of carbon equal to 10% ofthe columbium present, about 12.5% to 13.5% chromium, from 2.75% to 3.25% tungsten, about 1.75% to 2.25% nickel, about .3%- to .4% columbium, less than about 1.5 manganese, less than about 1.5% silicon and the balance substantially iron with residual impurities in ordinary amounts.

4." A ferrous article formed from a ductile heat and corrosion 'resistant' ferrous alloy comprising about .12% to .20% carbon plus an amount of carbon equal to 10% of the columbium present, about 12.5% to 13.5% chromium, about 2.75% to 3.25% tungsten, about 1.75% to 2.25% nickel, about .3% to .4% columbium, less than about 1.5% manganese, less than about 1.5% sili con and the balance substantially iron with residual 'im purities-in ordinary amounts, said article being characterized by a high degree of hardness and high stress-rupture propcrties at elevated temperatures along with a high degree of ductility.

References Cited'in the file of this patent UNITED STATES PATENTS Rose Jan. 7, 194 1 Rait et al May 21; 1957

Claims (1)

1. A FERROUS ALLOY OF HIGH HARDNESS AND STRESS-UPTURE PROPERTIES AT ELEVATED TEMPERATURES COMPRISING ABOUT .10% TO .25% CARBON PLUS AN AMOUNT OF CARBON EQUAL TO 10% OF THE COLUMBIUM PRESENT, ABOUT 10% TO 17% CHROMIUM, FROM 1% TO 5% TUNGSTEN, ABOUT .75% TO 2.75% NICKEL, ABOUT .3% TO 1% COLUMBIUM, LESS THAN ABOUT U.5% MANGANESE, LESS THAN ABOUT 1.5% SILICON AND

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