US3037272A - Method of making fine-grain chromium - Google Patents
Method of making fine-grain chromium Download PDFInfo
- Publication number
- US3037272A US3037272A US808303A US80830359A US3037272A US 3037272 A US3037272 A US 3037272A US 808303 A US808303 A US 808303A US 80830359 A US80830359 A US 80830359A US 3037272 A US3037272 A US 3037272A
- Authority
- US
- United States
- Prior art keywords
- container
- chromium
- powder
- temperature
- fine grain
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 title claims description 55
- 229910052804 chromium Inorganic materials 0.000 title claims description 39
- 239000011651 chromium Substances 0.000 title claims description 39
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 238000000034 method Methods 0.000 claims description 24
- 239000000843 powder Substances 0.000 claims description 23
- 238000010438 heat treatment Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- 238000003303 reheating Methods 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 4
- 238000001953 recrystallisation Methods 0.000 description 10
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- 238000001125 extrusion Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910017604 nitric acid Inorganic materials 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 239000010960 cold rolled steel Substances 0.000 description 2
- 238000005242 forging Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000005554 pickling Methods 0.000 description 2
- 238000007088 Archimedes method Methods 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000004320 controlled atmosphere Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/04—Making non-ferrous alloys by powder metallurgy
- C22C1/045—Alloys based on refractory metals
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/4981—Utilizing transitory attached element or associated separate material
Definitions
- the present invention relates to a method of producing very fine-grain solid chromium bodies, particularly rods, and more particularly, relates to a suitable heat treatment and extrusion process whereby chromium characterized by considerably improved physical and mechanical properties than that achievable by the processes of the prior art is obtained.
- chromium rods as for example, a grain size of ASTM 13, heretofore unobtainable, may be fabricated from chromium powders which rods and the like are characterized by a considerable increase and optimization of the mechanical properties thereof.
- our process makes chromium rod available far more economically than presently known methods.
- our process offers a means for producing such rods of a fine grain size.
- the powder was placed in an 11 gauge, 2 inch outside diameter seamless steel tube with a plug Then the powder was subjected to a pressure, applied to the cross-sectional area corresponding to the inner diameter of the tube,
- the container was then evacuated, in order to minimize the possibilities of oxidation, sealed and heated to 1000" C. for ninety (90) minutes; after which the powder was hot compacted by a 300 ton load (about 250,000 p.s.i.) applied to the above mentioned area.
- the temperature was selected in order to negate the possibilities of producing a coarse grain chromium. That is, by maintaining the temperature 'below the materials recrystallization temperature the crystalline structure does not reform into a larger more coarse grain.
- the recrystallization temperature of the particular material used occurred at 1050" C.
- the recrystallization temperature of the particular chromium powder used will be influenced by the degree of impurities in the powder. Andonce the recrystallization temperature of a particular powder used is determined, it is only necessary in the practice of this process to maintain the heats just below such temperature.
- the container was removed by pickling in a 20% nitric acid solution in water and recontained in a cold rolled steel can 7 inches long, 2.7 inches in outer diameter, and 1.8 inches in inner diameter. Chromium deforms irregularly when hot compacted, therefore, it was necessary to machine the rod in order to properly insert it into a new container of cold rolled steel 7 inches long, 2.7 inches in outer diameter and 1.8 inches in inner diameter.
- the container was evacuated, sealed and heated to 1000 C. for ninety minutes.
- the container may be heated in graphite.
- the container was extruded under a press load, applied to the total cross-sectional area of the container, of 370 to 400 tons, through a 0.750 inch die in a 2.80 inch liner.
- the rod produced thereby was then stripped by pickling in a 20% nitric acid solution in water.
- the resultant inch rod appeared to be of good quality, with a density 99.9% that of pure chromium as determined by displacement comparison (Archimedes Method) tests.
- Fine grain extruded powder Percentage elongation 0
- L0 is the original length and L is the/ length before rupture.
- the reduction of area was cor puted by the following equation:
- a process for the-fabrication of fine grain chromium rod the steps of: preparing a substantially fine grain chromium powder; cold compacting the powder at a predetermined pressure in a suitable container to increase the density of the powder; evacuating said container; sealing the container; heating the container with the compacted powder contained therein to a temperature of about 1000 C. for a period suflicient to insure a substantially constant temperature of about 1000 C. throughout; subjecting the container to'a predetermined load at said temperature to further density the powder; removing the container; reheating the chromium to a temperature of about 1000 C. in a second evacuated container; subjecting the container with the chromium therein to a press load in a liner whereby the material under load is extruded through a reduced opening at an end thereofrand removing the second container.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Powder Metallurgy (AREA)
Description
welded to the bottom thereof.
United States atent 3,037,272 METHOD OF MAKING FINE-GRAIN CHROMIUM Arthur G. Metcalfe, Park Forest, and Sheldon A. Spachner, Chicago, Ill., assignors to Armour Research Foundation of Illinois Institute of Technology, Chicago, Ill., a corporation of Illinois No Drawing. Filed Apr. 23, 1959, Ser. No. 808,303 3 Claims. (Cl. 29-4205) The present invention relates to a method of producing very fine-grain solid chromium bodies, particularly rods, and more particularly, relates to a suitable heat treatment and extrusion process whereby chromium characterized by considerably improved physical and mechanical properties than that achievable by the processes of the prior art is obtained.
Up to the present time there have been many methods for the preparation of chromium barstock, but to our knowledge none of these methods have utilized chromium powder as herein taught with the benefits resultiug therefrom. An example of such methods comprises the separate steps of: melting the cast material; forging; warm working; and recrystallization in order to obtain a stock of fine grain size. These methods exhibit inherent deficiencies in that they are both time consuming and costly. However, by our method of preparing fine grain chromium powder a much finer grain size is obtained. Furthermore, such size is obtained without the steps of melting and forging.
It is accordingly a primary object of our invention to provide a novel method of treating chromium powder to considerably enhance the properties of solid chromium resulting therefrom.
It is a further object of our invention to provide a novel method of treating chromium powder in a temperature controlled atmosphere to considerably enhance the properties of solid chromium resulting therefrom.
Other objects, features and advantages of our invention will become apparent to those skilled in this particular art from the following detailed disclosure thereof.
We have found that by a suitable heat treatment and extrusion process as hereinafter described in considerable detail that chromium rods, as for example, a grain size of ASTM 13, heretofore unobtainable, may be fabricated from chromium powders which rods and the like are characterized by a considerable increase and optimization of the mechanical properties thereof. In addition to the improved mechanical properties, our process makes chromium rod available far more economically than presently known methods. Furthermore, our process offers a means for producing such rods of a fine grain size.
In one particular example of our process We started with commercially available 325 mesh chromium powder which was analyzed as containing 0.3% iron and 0.5% oxygen. The first step was to reduce the iron content to 0.1% by agitating such chromium powder for five (5) minutes in a 2% solution of concentrated nitric acid in water followed by filtration and drying of the chromium residue.
Following this, the powder was placed in an 11 gauge, 2 inch outside diameter seamless steel tube with a plug Then the powder was subjected to a pressure, applied to the cross-sectional area corresponding to the inner diameter of the tube,
of 150 tons (about 125,000 p.s.i.). Thus, by cold compacting, a more dense chromium powder was obtained. The container was then evacuated, in order to minimize the possibilities of oxidation, sealed and heated to 1000" C. for ninety (90) minutes; after which the powder was hot compacted by a 300 ton load (about 250,000 p.s.i.) applied to the above mentioned area. The temperature was selected in order to negate the possibilities of producing a coarse grain chromium. That is, by maintaining the temperature 'below the materials recrystallization temperature the crystalline structure does not reform into a larger more coarse grain. The recrystallization temperature of the particular material used occurred at 1050" C. Of course, it will be understood by those skilled in this particular art, that the recrystallization temperature of the particular chromium powder used will be influenced by the degree of impurities in the powder. Andonce the recrystallization temperature of a particular powder used is determined, it is only necessary in the practice of this process to maintain the heats just below such temperature.
Following this, the container was removed by pickling in a 20% nitric acid solution in water and recontained in a cold rolled steel can 7 inches long, 2.7 inches in outer diameter, and 1.8 inches in inner diameter. Chromium deforms irregularly when hot compacted, therefore, it was necessary to machine the rod in order to properly insert it into a new container of cold rolled steel 7 inches long, 2.7 inches in outer diameter and 1.8 inches in inner diameter.
Thereafter, the container was evacuated, sealed and heated to 1000 C. for ninety minutes. In order to further reduce the possibilities of oxidation the container may be heated in graphite.
Following this, the container was extruded under a press load, applied to the total cross-sectional area of the container, of 370 to 400 tons, through a 0.750 inch die in a 2.80 inch liner. The rod produced thereby, was then stripped by pickling in a 20% nitric acid solution in water. The resultant inch rod appeared to be of good quality, with a density 99.9% that of pure chromium as determined by displacement comparison (Archimedes Method) tests.
The high temperature strength of this fine grain chromium is more than twice that of typical forged chromium. Furthermore, after extrusion it was found that the chromium had a much higher recrystallization temperature of over 1200 C. The increase in optimization of the mechanical properties of the chromium rod is best shown by reference to the following table in which data is obtained for chromium fabricated by our process and chromium prepared by prior art processes. The following data is quoted:
MECHANICAL PROPERTIES AT 750-755 C.
Yield UTS, Elong, Reduc- Strength, p.s.i. percent of Area, p.s.i. percent Fine grain extruded powder chromium 44, 800 53, 200 44 45 Forged chromium. 15, 200 22, 900 42 70 Extruded and forged chromium 21, 000 25, 600 50 MECHANICAL PROPERTIES AT 950960 C.
Fine grain extruded powder Percentage elongation: 0
wherein, L0 is the original length and L is the/ length before rupture. The reduction of area was cor puted by the following equation:
Percentage reduction of area-= 3 v wherein, A equals the original unstressed area and a equals the area of the rod prior to rupture. The data for Extruded and Forged Chromium is quoted from Transactions American Society for Metals, page 1077, volume 50, 1958.
It will thus be seen that we have provided a novel process whereby fine grain chromium is fabricated which exhibits highly increased mechanical properties as well as being less costly and time consuming than any processes heretofore known.
The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, for modifications will be obvious to those skilled in the art.
We claim as our invention:
1. In a process for the-fabrication of fine grain chromium rod, the steps of: preparing a substantially fine grain chromium powder; cold compacting the powder at a predetermined pressure in a suitable container to increase the density of the powder; evacuating said container; sealing the container; heating the container with the compacted powder contained therein to a temperature of about 1000 C. for a period suflicient to insure a substantially constant temperature of about 1000 C. throughout; subjecting the container to'a predetermined load at said temperature to further density the powder; removing the container; reheating the chromium to a temperature of about 1000 C. in a second evacuated container; subjecting the container with the chromium therein to a press load in a liner whereby the material under load is extruded through a reduced opening at an end thereofrand removing the second container.
2. In a process of the fabrication of improved fine grain chromium rod, the steps of; preparing a substantially fine grain chromium powder; compacting the powder at a pressure sufiicient to increase its density in a suitable container; evacuating said container; sealing the container in its evacuated condition; heating the container with the densified powder contained therein to a temperature just below the recrystallization tempera ture of the powder for a period sufiicient to establish a substantially constant temperature throughout; subjecting the container to another pressure load at said temperature to further density the chromium; removing the container; reheating the chromium to a temperature just below the recrystallization temperature of the powder in a second evacuated container; subjecting the container with the chromium therein to a press load in a liner whereby the material underload is extruded through a reduced opening at an end thereof; and removing said second container.
3. In a process for the fabrication of improved fine grain chromium rod, the steps of; preparing a substantially fine grain chromium powder; placing the powder in a ductile metal container which Will not alloy with the chromium powder at temperatures below the recrystallization temperature of the powder; cold compacting the powder at a pressure of approximately 125,000 pounds per square inch to produce a more dense chromium powder; evacuating the container of any gases which would react with the chromium powder at elevated temperatures; sealing the container in its evacuated condition; heating the container with the compacted powder contained therein to a temperature just below about 1050 C., the recrystallization temperature of the powder, for a period sufficient to insure substantially constant temperature throughout; hot compacting the powder at said temperature at a pressure of approximately 250,000 pounds per square inch to further density the chromium; removing the container; reheating the chromium to a temperature of about 1000 C. in a second evacuated container; subjecting the container with the chromium therein to a press load in a liner sufficient to extrude the container and chromium through a reduced opening at an end of the liner; and thereafter removing the container.
References Cited in the file of this patent UNITED STATES PATENTS 2,097,502 Southgate Nov. 2, 1937 2,206,395 Gertler July 2, 1940 2,290,734 Brassert July 21, 1942 2,476,208 Middleton July 12, 1949 2,588,734 Kolodneg Mar. 11, 1952 2,794,241 Dodds June 4, 1957 2,872,363 Macherey Feb. 3, .1959
5 lished in 1942 by The American Society of Metals, Cleveland, Ohio (copy in Div. 14).
Claims (1)
1. IN A PROCESS FOR THE FABRICATION OF FINE GRAIN CHROMIUM ROD, THE STEPS OF: PREPARING A SUBSTANTIALLY FINE GRAIN CHROMIUM POWDER; COLD COMPACTING THE POWDER AT A PREDETERMINED PRESSURE IN A SUITABLE CONTAINER TO INCREASE THE DENSITY OF THE POWDER; EVACUATING SAID CONTAINER; SEALING THE CONTAINER; HEATING THE CONTAINER WITH THE COMPACTED POWDER CONTAINED THEREIN TO A TEMPERATURE OF ABOUT 1000*C. FOR A PERIOD SUFFICIENT TO INSURE A SUBSTANTIALLY CONSTANT TEMPERATURE OF ABOUT 1000*C. THROUGHOUT; SUBJECTING THE CONTAINER TO A PREDETERMINED LOAD AT SAID TEMPERATURE TO FURTHER DENSIFY THE POWDER; REMOVING THE CONTAINER; REHEATING THE CHROMIUM TO A TEMPERATURE OF ABOUT 1000*C. IN A SECOND EVACUATED CONTAINER; SUBJECTING THE CONTAINER WITH THE CHROMIUM THEREIN TO A PRESS LOAD IN A LINER WHEREBY THE MATERIAL UNDER LOAD IS EXTRUDED THROUGH A REDUCED OPENING AT AN END THEREOF; AND REMOVING THE SECOND CONTAINER.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US808303A US3037272A (en) | 1959-04-23 | 1959-04-23 | Method of making fine-grain chromium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US808303A US3037272A (en) | 1959-04-23 | 1959-04-23 | Method of making fine-grain chromium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3037272A true US3037272A (en) | 1962-06-05 |
Family
ID=25198408
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US808303A Expired - Lifetime US3037272A (en) | 1959-04-23 | 1959-04-23 | Method of making fine-grain chromium |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3037272A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2097502A (en) * | 1933-03-18 | 1937-11-02 | Union Carbide & Carbon Corp | Method of and apparatus for producing rods and the like of comminuted material |
| US2206395A (en) * | 1938-08-05 | 1940-07-02 | Harry I Stein | Process for obtaining pure chromium, titanium, and certain other metals and alloys thereof |
| US2290734A (en) * | 1940-02-14 | 1942-07-21 | Minerals And Metals Corp | Manufacture of metal products |
| US2476208A (en) * | 1943-10-28 | 1949-07-12 | Int Nickel Co | Sintered precious metal product |
| US2588734A (en) * | 1948-05-14 | 1952-03-11 | Atomic Energy Commission | Pretreatment of beryllium prior to coating |
| US2794241A (en) * | 1952-12-31 | 1957-06-04 | Harry W Dodds | Fabrication of intricate shapes from beryllium |
| US2872363A (en) * | 1948-07-14 | 1959-02-03 | Robert E Macherey | Method of working beryllium |
-
1959
- 1959-04-23 US US808303A patent/US3037272A/en not_active Expired - Lifetime
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2097502A (en) * | 1933-03-18 | 1937-11-02 | Union Carbide & Carbon Corp | Method of and apparatus for producing rods and the like of comminuted material |
| US2206395A (en) * | 1938-08-05 | 1940-07-02 | Harry I Stein | Process for obtaining pure chromium, titanium, and certain other metals and alloys thereof |
| US2290734A (en) * | 1940-02-14 | 1942-07-21 | Minerals And Metals Corp | Manufacture of metal products |
| US2476208A (en) * | 1943-10-28 | 1949-07-12 | Int Nickel Co | Sintered precious metal product |
| US2588734A (en) * | 1948-05-14 | 1952-03-11 | Atomic Energy Commission | Pretreatment of beryllium prior to coating |
| US2872363A (en) * | 1948-07-14 | 1959-02-03 | Robert E Macherey | Method of working beryllium |
| US2794241A (en) * | 1952-12-31 | 1957-06-04 | Harry W Dodds | Fabrication of intricate shapes from beryllium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE2419014C3 (en) | Method of manufacturing stainless steel pipes and application of the method to the manufacture of composite pipes | |
| US2809891A (en) | Method of making articles from aluminous metal powder | |
| US3655458A (en) | Process for making nickel-based superalloys | |
| US4297136A (en) | High strength aluminum alloy and process | |
| US3462248A (en) | Metallurgy | |
| JPS6312926B2 (en) | ||
| US5445787A (en) | Method of extruding refractory metals and alloys and an extruded product made thereby | |
| US3639179A (en) | Method of making large grain-sized superalloys | |
| US4693864A (en) | Powder metallurgy process for producing steel articles | |
| US2966731A (en) | Aluminum base alloy powder product | |
| US2966736A (en) | Aluminum base alloy powder product | |
| US4143208A (en) | Method of producing tubes or the like and capsule for carrying out the method as well as blanks and tubes according to the method | |
| US2678271A (en) | Molybdenum-zirconium alloys | |
| US3189988A (en) | Method of making copper tubing | |
| US2818339A (en) | Method for producing malleable and ductile beryllium bodies | |
| US2781903A (en) | Hot transformation of metals | |
| US3037272A (en) | Method of making fine-grain chromium | |
| US4428778A (en) | Process for producing metallic chromium plates and sheets | |
| US5482672A (en) | Process for extruding tantalum and/or niobium | |
| US2966732A (en) | Aluminum base alloy powder product | |
| US3150975A (en) | Method of making intermetallic compound-composition bodies | |
| US3619894A (en) | Process for the production of a composite material al-mg-al2o3-mgo | |
| US3390985A (en) | Consolidation and forming by high-energy-rate extrusion of powder material | |
| US3428717A (en) | Method of extruding metallic carbides and in particular uranium monocarbide | |
| DE10215086B4 (en) | Foamable metal body, process for its production and its use |