US2819194A - Method of aging titanium base alloys - Google Patents
Method of aging titanium base alloys Download PDFInfo
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- US2819194A US2819194A US404392A US40439254A US2819194A US 2819194 A US2819194 A US 2819194A US 404392 A US404392 A US 404392A US 40439254 A US40439254 A US 40439254A US 2819194 A US2819194 A US 2819194A
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- 229910045601 alloy Inorganic materials 0.000 title claims description 46
- 239000000956 alloy Substances 0.000 title claims description 46
- 239000010936 titanium Substances 0.000 title claims description 28
- 229910052719 titanium Inorganic materials 0.000 title claims description 28
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 title claims description 27
- 238000000034 method Methods 0.000 title claims description 16
- 230000032683 aging Effects 0.000 title claims description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 41
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 30
- 239000011651 chromium Substances 0.000 claims description 27
- 229910052751 metal Inorganic materials 0.000 claims description 17
- 239000002184 metal Substances 0.000 claims description 17
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 16
- 229910052804 chromium Inorganic materials 0.000 claims description 16
- 229910052742 iron Inorganic materials 0.000 claims description 16
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 15
- 229910052757 nitrogen Inorganic materials 0.000 claims description 15
- 229910052760 oxygen Inorganic materials 0.000 claims description 15
- 239000001301 oxygen Substances 0.000 claims description 15
- 238000010438 heat treatment Methods 0.000 claims description 11
- 238000005275 alloying Methods 0.000 claims description 8
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 7
- 229910052721 tungsten Inorganic materials 0.000 claims description 7
- 239000010937 tungsten Substances 0.000 claims description 7
- 230000003750 conditioning effect Effects 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 3
- 238000004881 precipitation hardening Methods 0.000 claims description 3
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 2
- 238000007792 addition Methods 0.000 description 12
- 238000001816 cooling Methods 0.000 description 8
- 239000011572 manganese Substances 0.000 description 8
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 6
- 229910001069 Ti alloy Inorganic materials 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 229910052750 molybdenum Inorganic materials 0.000 description 6
- 239000011733 molybdenum Substances 0.000 description 6
- 229910001021 Ferroalloy Inorganic materials 0.000 description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- -1 33% Chemical compound 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000010791 quenching Methods 0.000 description 3
- 238000003303 reheating Methods 0.000 description 3
- 229910000604 Ferrochrome Inorganic materials 0.000 description 2
- 229910000616 Ferromanganese Inorganic materials 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000000135 prohibitive effect Effects 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910001309 Ferromolybdenum Inorganic materials 0.000 description 1
- 229910001145 Ferrotungsten Inorganic materials 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical class [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 description 1
- 229910002056 binary alloy Inorganic materials 0.000 description 1
- 229910052729 chemical element Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C14/00—Alloys based on titanium
Definitions
- This invention relates to new and improved procedure for making titanium base alloys, and to alloys produced thereby.
- titanium is a relatively new metal, the production of its alloys has heretofore been more or less on a laboratory scale. Since it is recognized that titanium has a great afiinity for contaminating materials in the production of its alloys, it has heretofore been the practice to employ relatively pure alloying elements. This has made the production of such alloys almost prohibitive in cost and has limited their field of application.
- titanium alloys with strength and hardness much better than those obtained for commercially pure metal are needed. Since the weight of titanium is only about 60% of that of steel, titanium alloys with tensile strengths exceeding 140,000 p. s. i. and having moderate ductility, i. e., about will compare favorably with best alloy steels and aluminum-base alloys for structural uses, such as aircraft engines and frames, turbines, etc. The superior strength per unit weight of titanium alloys together with their excellent corrosion resistance will make it possible to reduce the dead weight of moving parts in transportation and power generating equipment with a resultant substantial increase in operating efficiency.
- ferroalloys of these metals which are easily prepared and readily available, are the most economical means of adding alloying metals to titanium. They not only are suitable for making titaniumbase alloys of the desired ternary and higher order, but alsoproduceeven betteralloys than those produced 'by the introduction of pure elements.
- the harder metals such as chromium, molybdenum, tungsten or manganese. become more readily soluble in molten titanium when they are introduced as ferroalloys, and that thepresence of iron complements and enhances the effects of the chromium, molybdenum, etc. This is believed to be an outsanding development in the art although it is directly contrary to: prior teaching as to the making of titanium-base alloys. 11: not only provides an improved product,-.but a much more economical one.
- oxygen or nitrogen additions may be made as titanium dioxide or titanium nitride compounds which are also commercially available or may be incorporatedwith the ferroalloy.
- a high nitrogen grade of ferrochromium is commercially obtainable in several analysis ranges, for example, suchas chromium, 33%, iron, and 1.4% nitrogen.
- the following table is representative of properties obtained in forgediiand annealed titaniumihathas been cooled with proper additions of ferrochromium, ferromolybdenum, ferrotungsten, and ferromanganese, with or without supplementary additions of nitrogen or oxygen:
- the alloys of Table III may be used in various conditions of heat treatment depending upon the specific properties desired. Hot working within a temperature range of about 1400" to 1800 F., followed by cooling in air produces desirable properties for most structural uses. A subsequent anneal or stress relief is, however, preferred to obtain uniformity of properties. This is accomplished by reheating to a temperature within the range of about 1200 to 1606 F. and cooling at a suitable rate. Alloys A B C and E to M, inclusive, respond favorably to heat treatment and may be hardened by rapid cooling, as water quenching from temperatures above about 1500 F., or softened by relatively slow cooling from the same temperature.
- Alloys A B C and D respond favorably to heat treatment of a different type from the above groups.
- All of the alloys of Table III may be hardened somewhat following moderately rapid cooling from a temperature above about 1200 F., by an aging or precipitation hardening mechanism on reheating and holding for various periods in the temperature range of about 700 to 1200 F. The time of holding is less, the higher the aging temperature in this range and the effect is reversible, so that the alloy may be softened again by reheating to a higher temperature. All the alloys may also be hardened by cold working, i. e. mechanical reduction in crosssectional area at temperatures below about 1200 F. and may be softened again by heating to temperatures above about 1200 F. for various periods, the temperature and time employed in the softening operation will depend on the degree of cold work accomplished.
- All of the alloys and commercially pure titanium may be surface hardened by heating in air or atmospheres, mixtures, or fused baths that provide nitrogen or oxygen for combination with the titanium. It has been found, for example, that titanium heated in the presence of oxygen for about one hour at 1900 F. is hardened for a depth of .050 of an inch below the surface with a maximum surface hardness of 400 Brinell. Similar surface hardening effects are produced by heating titanium or the alloys in nitrogen-rich atmospheres, such as ammonia gas at temperatures as low as 950 F. The depth and degree of hardness produced is controlled by the time and temperature of exposure as Well as the composition of the atmosphere or bath used.
- all elements are made from commercially available titanium metal, such as produced by the reaction of chemically pure titanium tetrachloride with magnesium metal and which contains approximately .02% nitrogen, .1% oxygen, and .l% iron as the principal impurities.
- titanium metal such as produced by the reaction of chemically pure titanium tetrachloride with magnesium metal and which contains approximately .02% nitrogen, .1% oxygen, and .l% iron as the principal impurities.
- We prefer to produce our titanium alloys in accordance with the Herres arc-melting procedure see application filed September 13, 1949, Serial No. 115,454, now abandoned
- the alloys may be prepared by any melting or powder metallurgy technique that will produce metal of the desired chemical composition.
- ferrocompounds of one or more of the elements chromium, molybdenum, tungsten, or manganese are added to the titanium While it is in a molten state and while an ambient atmosphere is maintained that is non-contaminating of the titanium. Such additions may be eifected through an air lock into an enclosed furnace or crucible While a titanium halide is being reduced therein.
- the titanium halide or compound upon reduction is immediately converted to molten metal to which the alloying additions may be made.
- a proportionate amount of nitrogen and oxygen or a combination of them may be made to obtain the desired ultimate content of the alloy as indicated by the tables.
- Alloys M, M, N, and 0 when made by the additions of ferromanganese, may contain a small amount of iron and oxygen as impurities, for example, about .1% or less, each, relatively small percentages of such impurities do not appear to have deleterious elfects in these managanese alloys, although they can be substantially removed by well known procedure.
- alloys A B C and D it has been found that with normal impurities of about .02% nitrogen, about .1% oxygen, and .1% iron, a chromium addition will retain the body-centered structure on water quenching, but not on air cooling, while a chromium addition will retain it on air cooling.
- An alloy of 4.8% iron and 10% chromium with .2% nitrogen, and .1% oxygen as impurities, will retain the body-centered cubic structure on air cooling. It thus appears that the combination of iron and chromium definitely favors retention of such structure.
- Small amounts of oxygen or nitrogen appear beneficial in improving the properties of the bodycentered structure alloys, but in general, appear to have a non-controlling influence as to the body-centered lattice structure. In any event, a body-centered lattice structure is assured by water-quenching alloys containing about 4% iron and 8% chromium through the upper limit of about 7% iron and 14% chromium.
- a method of conditioning a ternary and higher titanium base alloy which is responsive to the following defined treatment and which consists essentially of an alloying gas selected from the group consisting of nitrogen and oxygen with a range of .02 to .40% each, an alloying metal selected from the group consisting of and within the specified ranges of about .1 to 10% iron, 1.5 to 20% chromium, 1 to 5% molybdenum, 1.5 to 5% tungsten, and 1 to 10% manganese, and the remainder titanium which comprises, aging and precipitation hardening the alloy by heating and holding it within a temperature range of about 700 to 1200 F.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
Description
METHOD OF AGlNG TIT BASE ALLOYS .SchnylerA. l-llerres, Las Vegas, and Thomas K. Redden,
Boulder City, Nev., assignors to Allegheny Ludlum Steel Corporation, Breckenridge, Pa., a corporation of Pennsylvania No Drawing. Original application September 29, 1949,
Serial No. 118,723. Divided and this application 3am!- 'ary15, 1954, Serial No. 404,392
' 3 Claims. (Cl. 148-4130) This invention relates to new and improved procedure for making titanium base alloys, and to alloys produced thereby.
Since titanium is a relatively new metal, the production of its alloys has heretofore been more or less on a laboratory scale. Since it is recognized that titanium has a great afiinity for contaminating materials in the production of its alloys, it has heretofore been the practice to employ relatively pure alloying elements. This has made the production of such alloys almost prohibitive in cost and has limited their field of application.
Pure titanium metal which, itself, is not commercially obtainable, is very soft and ductile. It has been indicated that annealed high purity titanium metal has a tensile strength of about 32,000 p. s. i., a yield strength of about 17,500 p. s. i., 55% elongation, and 73 Brinell hardness. Commercially available titanium sponge metal melted into ingots without appreciable contamination, forged into bars, and annealed at 1500 F. on an average, has a tensile strength of about 70,000 p. s. i., a yield strength of about 60,0000 p. s. i., 30% elongation, and about 160 Brinell hardness. The higher strength and hardness and the lower ductility is accounted for by the impurities, particularly oxygen.
Although a relatively high ductility of metal is required for fabricating cold drawn tubing, and this indicates the use of titanium metal of the highest practical purity, we have determined that for most applications, titanium alloys with strength and hardness much better than those obtained for commercially pure metal are needed. Since the weight of titanium is only about 60% of that of steel, titanium alloys with tensile strengths exceeding 140,000 p. s. i. and having moderate ductility, i. e., about will compare favorably with best alloy steels and aluminum-base alloys for structural uses, such as aircraft engines and frames, turbines, etc. The superior strength per unit weight of titanium alloys together with their excellent corrosion resistance will make it possible to reduce the dead weight of moving parts in transportation and power generating equipment with a resultant substantial increase in operating efficiency.
Additions of nitrogen, oxygen, carbon, iron, tungsten, molybdenum, or chromium as binary alloys with tita- 2,819,194 Patented Jan.,7, 1958 nium gave the following results:formhot-forgedand annealed alloys:
We have determinedthat combinations of oxygen or nitrogen with. the elements chromium, molybednum,:and tungsten or iron, manganese and nickel'provide more beneficial results than the use of any of the single ele ments. Pure chromium, molybdenum, tungsten or manganese are relatively scarce and expensive. 1 Thus, if, as has been the, practice heretofore, relatively pure metals are employed, the expense becomes prohibitive.
In endeavoring to find a solution to the problem'thus presented, we discovered that ferroalloys of these metals which are easily prepared and readily available, are the most economical means of adding alloying metals to titanium. They not only are suitable for making titaniumbase alloys of the desired ternary and higher order, but alsoproduceeven betteralloys than those produced 'by the introduction of pure elements. We have determined that the harder metals, such as chromium, molybdenum, tungsten or manganese. become more readily soluble in molten titanium when they are introduced as ferroalloys, and that thepresence of iron complements and enhances the effects of the chromium, molybdenum, etc. This is believed to be an outsanding development in the art although it is directly contrary to: prior teaching as to the making of titanium-base alloys. 11: not only provides an improved product,-.but a much more economical one.
In accordance with our procedure, oxygen or nitrogen additions may be made as titanium dioxide or titanium nitride compounds which are also commercially available or may be incorporatedwith the ferroalloy. A high nitrogen grade of ferrochromium is commercially obtainable in several analysis ranges, for example, suchas chromium, 33%, iron, and 1.4% nitrogen. The following table is representative of properties obtained in forgediiand annealed titaniumihathas been cooled with proper additions of ferrochromium, ferromolybdenum, ferrotungsten, and ferromanganese, with or without supplementary additions of nitrogen or oxygen:
4 content of the chromium or iron or both of them, a high temperature body-centered cubic lattice structure of titanium is stabilized and retained at room temperature. This Table II Hard- Tensile Yield Elong, Alloy Addition, Percent ness. Strength, Strength, Percent BH p. s. i p. s. i
1 .04 N, 2.0 Cr, 275 120,000 107, 500 22 2 .25 N, 2.0 Cr, 330 153, 500 133, 000 18 3- .25 N, 2.0 Cr. 340 162, 000 148, 000 4- .05 N, 3.4 CI, 330 156, 000 142. 000 16 5- .25 N, 3.4 Ct. 360 172,000 151,000 6. .05 N, 4.2 Cr, 330 154. 000 140. 000 17 7.-- .1 N, 4.1 Cr, 1. 340 160, 000 145. 000 15 8 .2 N, 4.2 Oz, 1. 380 183, 000 174, 000 13 9 .1 N, 5.0 Cr, 2. 388 189, 000 3 10.-.- .2 N, 8.0 Cr, 3. 345 168,000 153, 000 0 11 .2 N, 10.0 C1, F 350 176, 000 163, 000 13 12 .05 N. 14.0 Cr, 9 Fe 360 15 13 .25 N, 3.0 M0, 405 7 14---- .25 N, 2.5 W, 315 15 .25 0, 3.5 0r, 340 19 16 .25 O, 2.5 W, 310 140, 500 H 20 17-- .25 N, 5.0 Fe 420 207, 000 186,000 3 18 .25 N, 5.0 Mn 370 173, 000 160, 000 16 The alloys of Table II may be summarized as follows:
The following table gives percentage analysis ranges for titanium-base alloys of improved characteristics that have been produced in accordance with our procedure: Table III 0= 02-.40 0=.02-.40 A Fe 75-10 A: Fe=4.0-7.0
Or=l.5-l4.0 Gr=8.014.0 N=.05.25 N=.05.20 B Fe=.75-7.0 B: Fe=4.07.0
Cr=1.514.0 1 Cr=8.014.0 N=.02-.25 o=.02-.40 C 0=.02-.40 C N=.02-.25 Cr=1 5-200 2 =4.0-7.0 Fe= 75-100 =s.014.o
o=0.02-0.40 =0.0t r0.40 D Fe=0.53.0 E Fe- .5 =0.02-0.30
Mo=1.0-5.0 Mo=l.0-5.0 =0.5-3.0 =1.0-5.0 0=0.02-0.40 N=0.020.40 =0.02-0.40 G Fe=0.52.0 H Fe=0.52.0 =0.02-0.40
w=1.5-5.0 W=l.5-5.0 =0.5-2.0 =1.55.0 0=0.02-0.40 N=0.02-0.25 =0.02-0.40 .I Fo=0.1-3.0 K Fe= 1-3.0 =0.02-0.a0 Mn=1.07.0 Mn-I 0-7 0 =0.1-5.0
65 i? N=.1- o=.1-.3 {Mn=2.0-6 o {Mn=2.0-6.0 .02-.20
LgllO N=.1.25 0= -3 .0 .0 i Fe=2.5-6.0 l re 02-.20
The alloys of Table III may be used in various conditions of heat treatment depending upon the specific properties desired. Hot working within a temperature range of about 1400" to 1800 F., followed by cooling in air produces desirable properties for most structural uses. A subsequent anneal or stress relief is, however, preferred to obtain uniformity of properties. This is accomplished by reheating to a temperature within the range of about 1200 to 1606 F. and cooling at a suitable rate. Alloys A B C and E to M, inclusive, respond favorably to heat treatment and may be hardened by rapid cooling, as water quenching from temperatures above about 1500 F., or softened by relatively slow cooling from the same temperature.
Alloys A B C and D respond favorably to heat treatment of a different type from the above groups. On heating to a temperature above about 1500 F. and cooling at a rate that may be slower, the higher the provides a softer, more ductile metal than is obtained if the same alloy is cooled sufiiciently slowly to alloy the titanium and transform it to its normal hexagonal close packed lattice structure.
All of the alloys of Table III may be hardened somewhat following moderately rapid cooling from a temperature above about 1200 F., by an aging or precipitation hardening mechanism on reheating and holding for various periods in the temperature range of about 700 to 1200 F. The time of holding is less, the higher the aging temperature in this range and the effect is reversible, so that the alloy may be softened again by reheating to a higher temperature. All the alloys may also be hardened by cold working, i. e. mechanical reduction in crosssectional area at temperatures below about 1200 F. and may be softened again by heating to temperatures above about 1200 F. for various periods, the temperature and time employed in the softening operation will depend on the degree of cold work accomplished.
All of the alloys and commercially pure titanium may be surface hardened by heating in air or atmospheres, mixtures, or fused baths that provide nitrogen or oxygen for combination with the titanium. It has been found, for example, that titanium heated in the presence of oxygen for about one hour at 1900 F. is hardened for a depth of .050 of an inch below the surface with a maximum surface hardness of 400 Brinell. Similar surface hardening effects are produced by heating titanium or the alloys in nitrogen-rich atmospheres, such as ammonia gas at temperatures as low as 950 F. The depth and degree of hardness produced is controlled by the time and temperature of exposure as Well as the composition of the atmosphere or bath used.
In accordance with our preferred procedure, all elements are made from commercially available titanium metal, such as produced by the reaction of chemically pure titanium tetrachloride with magnesium metal and which contains approximately .02% nitrogen, .1% oxygen, and .l% iron as the principal impurities. We prefer to produce our titanium alloys in accordance with the Herres arc-melting procedure (see application filed September 13, 1949, Serial No. 115,454, now abandoned) which is carried out in a Water-cooled copper crucible and in an atmosphere that is non-contaminating of the titanium. Also, the alloys may be prepared by any melting or powder metallurgy technique that will produce metal of the desired chemical composition. In accordance with our procedure, ferromctal, and particularly, ferrocompounds of one or more of the elements chromium, molybdenum, tungsten, or manganese are added to the titanium While it is in a molten state and while an ambient atmosphere is maintained that is non-contaminating of the titanium. Such additions may be eifected through an air lock into an enclosed furnace or crucible While a titanium halide is being reduced therein.
In accordance with such procedure, the titanium halide or compound upon reduction is immediately converted to molten metal to which the alloying additions may be made. A proportionate amount of nitrogen and oxygen or a combination of them may be made to obtain the desired ultimate content of the alloy as indicated by the tables.
Our heat treatment as set forth herein, although specifically worked out from the standpoint of titanium-base alloys of a ternary or high order, and particularly, ternary or higher alloys containing iron, may be used where applicable to other titanium alloys as indicated herein.
In Table III A, B, and C represent broader ranges of the alloys within their representative groups, while alloys A A B B and C and C are preferred ranges within the specified broader ranges.
Alloys M, M, N, and 0 when made by the additions of ferromanganese, may contain a small amount of iron and oxygen as impurities, for example, about .1% or less, each, relatively small percentages of such impurities do not appear to have deleterious elfects in these managanese alloys, although they can be substantially removed by well known procedure.
It should be noted that the specific alloys 17, 18 (P' and M) of column 3 and M to R, inclusive, of column 3 are, in themselves, the sole invention of Thomas K. Redden, and that their disclosure herein is made (Without prejudice to his rights therein) to show that iron or ferro additions are beneficial, and to better or more completely illustrate the procedure for making and conditioning titanium-base alloys which with the other alloys (except those above specifically listed) constitute our joint invention or inventions.
As to alloys A B C and D, it has been found that with normal impurities of about .02% nitrogen, about .1% oxygen, and .1% iron, a chromium addition will retain the body-centered structure on water quenching, but not on air cooling, while a chromium addition will retain it on air cooling. An alloy of 4.8% iron and 10% chromium with .2% nitrogen, and .1% oxygen as impurities, will retain the body-centered cubic structure on air cooling. It thus appears that the combination of iron and chromium definitely favors retention of such structure. Small amounts of oxygen or nitrogen appear beneficial in improving the properties of the bodycentered structure alloys, but in general, appear to have a non-controlling influence as to the body-centered lattice structure. In any event, a body-centered lattice structure is assured by water-quenching alloys containing about 4% iron and 8% chromium through the upper limit of about 7% iron and 14% chromium.
This application is a division of application Ser. No. 118,723, filed September 29, 1949, now abandoned.
What we claim is:
1. A method of conditioning a ternary and higher titanium base alloy which is responsive to the following defined treatment and which consists essentially of an alloying gas selected from the group consisting of nitrogen and oxygen with a range of .02 to .40% each, an alloying metal selected from the group consisting of and within the specified ranges of about .1 to 10% iron, 1.5 to 20% chromium, 1 to 5% molybdenum, 1.5 to 5% tungsten, and 1 to 10% manganese, and the remainder titanium which comprises, aging and precipitation hardening the alloy by heating and holding it within a temperature range of about 700 to 1200 F.
2. A method as defined in claim 2 wherein the alloying gas is introduced into the titanium base alloy by ferroalloy additions to a molten titanium melt.
3. A method of conditioning as defined in claim 2 wherein the alloy is preliminarily hardened by heating it to a temperature above about 1200" F. and is moderately rapidly cooled from such temperature before the alloy is aged and precipitation hardened.
References Cited in the file of this patent UNITED STATES PATENTS 1,674,959 Dean June 26, 1928 2,169,193 Comstock Aug. 8, 1939 2,317,979 Dean et a1 May 4, 1943 2,520,753 Ball et al Aug. 29, 1950 2,554,031 Jafiee et al. May 22, 1951 2,588,007 Jafiee Mar. 4, 1952 OTHER REFERENCES Preparation and Evaluation of Titanium Alloys, Summary Report; Part III covering the period May 18, 1948,
to July 30, 1949.
Patent No. 2,819,194
U. S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION January '7, 1958 Schuyler A Herres et a1,
appears in the printed specification I It is hereby certified that error correction and that the said Letters of the above numbered patent requiring Patent should read as corrected below.
read 60,000 column 3,, in the Column 1, line 35,, for "60,0000" summary of Table II, second column thereof, last line for "Fe: 050" read Fe=5.,0 column 6, lines 23 and 26 for the claim reference numeral '2', each occurrence, read l Signed and sealed this 1st day of April 1958 (SEAL) Attest: I
KARL mAXLINE ROBERT c. WATSON C'omnissioner of Patents Attesting Officer
Claims (1)
1. A METHOD OF CONDITIONING A TERNARY AND HIGHER TITANIUM BASE ALLOY WHICH IS RESPONSIVE TO THE FOLLOWING DEFINED TREATMENT AND WHICH CONSISTS ESSENTIALLY OF AN ALLOYING GAS SELECTED FROM THE GROUP CONSISTING OF NITROGEN AND OXYGEN WITH A RANGE OF .02 TO .04% EACH, AND ALLOYING METAL SELECTED FROM THE GROUP CONSISTING OF AND WITHIN THE SPECIFIED RANGES OF ABOUT .1 TO 10% IRON, 1.5 TO 20% CHROMIUM, 1 TO 5% MOLYBENUM, 1.5 TO 5% TUNGSTEN, AND 1 TO 10% MANGANESE, AND THE REMAINDER TITANIUM WHICH COMPRISES, AGING AND PRECIPITATION HARDENING THE ALLOY BY HEATING AND HOLDING IT WITHIN A TEMPERATURE RANGE OF ABOUT 700* TO 1200*F.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US404392A US2819194A (en) | 1949-09-29 | 1954-01-15 | Method of aging titanium base alloys |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US11872349A | 1949-09-29 | 1949-09-29 | |
| US404392A US2819194A (en) | 1949-09-29 | 1954-01-15 | Method of aging titanium base alloys |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2819194A true US2819194A (en) | 1958-01-07 |
Family
ID=26816677
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US404392A Expired - Lifetime US2819194A (en) | 1949-09-29 | 1954-01-15 | Method of aging titanium base alloys |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2819194A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3147115A (en) * | 1958-09-09 | 1964-09-01 | Crucible Steel Co America | Heat treatable beta titanium-base alloys and processing thereof |
| US4631092A (en) * | 1984-10-18 | 1986-12-23 | The Garrett Corporation | Method for heat treating cast titanium articles to improve their mechanical properties |
| US4871400A (en) * | 1987-04-28 | 1989-10-03 | Nippon Steel Corporation | Method for producing titanium strip having small proof strength anisotropy and improved ductility |
| US5685924A (en) * | 1995-07-24 | 1997-11-11 | Howmet Research Corporation | Creep resistant gamma titanium aluminide |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1674959A (en) * | 1926-01-23 | 1928-06-26 | Western Electric Co | Hardenable alloy |
| US2169193A (en) * | 1938-01-06 | 1939-08-08 | Titanium Alloy Mfg Co | Chromium-titanium-silicon alloy |
| US2317979A (en) * | 1941-05-14 | 1943-05-04 | Chicago Dev Co | Manganese-base alloy |
| US2520753A (en) * | 1948-01-06 | 1950-08-29 | Magnesium Elektron Ltd | Heat-treatment of magnesium base alloys |
| US2554031A (en) * | 1949-10-20 | 1951-05-22 | Remington Arms Co Inc | Titanium base alloy |
| US2588007A (en) * | 1948-10-05 | 1952-03-04 | Battelle Development Corp | Titanium-molybdenum-chromium alloys |
-
1954
- 1954-01-15 US US404392A patent/US2819194A/en not_active Expired - Lifetime
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1674959A (en) * | 1926-01-23 | 1928-06-26 | Western Electric Co | Hardenable alloy |
| US2169193A (en) * | 1938-01-06 | 1939-08-08 | Titanium Alloy Mfg Co | Chromium-titanium-silicon alloy |
| US2317979A (en) * | 1941-05-14 | 1943-05-04 | Chicago Dev Co | Manganese-base alloy |
| US2520753A (en) * | 1948-01-06 | 1950-08-29 | Magnesium Elektron Ltd | Heat-treatment of magnesium base alloys |
| US2588007A (en) * | 1948-10-05 | 1952-03-04 | Battelle Development Corp | Titanium-molybdenum-chromium alloys |
| US2554031A (en) * | 1949-10-20 | 1951-05-22 | Remington Arms Co Inc | Titanium base alloy |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3147115A (en) * | 1958-09-09 | 1964-09-01 | Crucible Steel Co America | Heat treatable beta titanium-base alloys and processing thereof |
| US4631092A (en) * | 1984-10-18 | 1986-12-23 | The Garrett Corporation | Method for heat treating cast titanium articles to improve their mechanical properties |
| US4871400A (en) * | 1987-04-28 | 1989-10-03 | Nippon Steel Corporation | Method for producing titanium strip having small proof strength anisotropy and improved ductility |
| US5685924A (en) * | 1995-07-24 | 1997-11-11 | Howmet Research Corporation | Creep resistant gamma titanium aluminide |
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