US20060280642A1 - Method of storing nitrogen trifluoride - Google Patents
Method of storing nitrogen trifluoride Download PDFInfo
- Publication number
- US20060280642A1 US20060280642A1 US11/293,782 US29378205A US2006280642A1 US 20060280642 A1 US20060280642 A1 US 20060280642A1 US 29378205 A US29378205 A US 29378205A US 2006280642 A1 US2006280642 A1 US 2006280642A1
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- United States
- Prior art keywords
- vessel
- chromium
- gas
- molybdenum
- steel
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- 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.)
- Abandoned
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L5/00—Gas handling apparatus
- B01L5/02—Gas collection apparatus, e.g. by bubbling under water
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L5/00—Gas handling apparatus
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/082—Compounds containing nitrogen and non-metals and optionally metals
- C01B21/083—Compounds containing nitrogen and non-metals and optionally metals containing one or more halogen atoms
- C01B21/0832—Binary compounds of nitrogen with halogens
- C01B21/0835—Nitrogen trifluoride
Definitions
- the present invention relates, generally, to a method of storing nitrogen trifluoride (NF 3 ), and more particularly, to a method of storing NF3 gas, using a chromium-molybdenum steel vessel manufactured through a deep drawing ironing (DDI) process.
- NF 3 nitrogen trifluoride
- DAI deep drawing ironing
- DDI process a process of manufacturing a cylindrical vessel having a closed bottom using a drawing die.
- a machining tool comprising one pair of upper and lower pieces (punch and die) made of carbon tool steel or alloy tool steel is called the drawing die.
- the die is mounted to a press, and a sheet material is positioned in the press and fastened thereon. Then, when the punch presses the sheet material, the sheet material is drawn and thus shaped into the body of a cylindrical vessel in cup form such that a bottom surface and a side wall surface are integrated.
- the upper opening of the vessel thus produced is sealed and a valve is connected at an injection port thereof, to complete a high-pressure vessel for gas storage.
- the DDI process is also referred to as plug drawing.
- NF 3 gas is an expensive chemical serving as an etching agent for the fabrication of a semiconductor device.
- the NF 3 gas may be prepared through the direct reaction of fluorine gas and ammonia, the reaction of ammonium hydrogenfluoride (NF 4 HF 2 ) and fluorine gas, or the electrolysis of an ammonium hydrogenfluoride melt.
- NF 3 is supplied to users by being prepared as a highly pure liquid and then charged in a 20 ⁇ 50 L vessel in a high-pressure gas state.
- NF 3 is used as an etching agent for the fabrication of a semiconductor device, it must have high purity of 99.99% or more.
- the semiconductor process requires NF 3 gas having purity levels of 3 ppm or less N 2 , 3 ppm or less O 2 , 1 ppm or less CO 2 , 20 ppm or less CF 4 , 1 ppm or less H 2 O, 1 ppm or less N 2 O, and 1 ppm or less HF.
- NF 3 which is highly reactive gas, should be stored in a specific vessel so as not to be deteriorated during storage or circulation.
- a manganese steel vessel As a vessel for storing NF 3 gas, a manganese steel vessel has been conventionally used.
- the manganese steel vessel is manufactured by subjecting a pipe formed of manganese steel containing 0.5 ⁇ 1.5% manganese to a shaping process using heat to produce a cylindrical sealing vessel, and then conducting polishing and washing of the vessel thus produced.
- the manganese steel vessel which is a general NF 3 storage vessel, may be used after a polishing process has been conducted on the inner surface of the vessel, to realize inner surface roughness (Ra) of 10 ⁇ m or less, and washing and drying of the vessel have been conducted in a vacuum to completely remove inner impurities.
- NF 3 stored therein becomes acidic over time, resulting in deteriorated NF 3 .
- nitric acid is detected from NF 3 stored in the manganese steel vessel, the vessel used is regarded as unsuitable for storage of NF 3 .
- NF 3 storage methods resulted in the finding that NF 3 stored in a chromium-molybdenum steel vessel manufactured through a DDI process does not deteriorate even after a long time elapses, although NF 3 , which is stored in a conventional manganese steel vessel having an Ra of 10 ⁇ m or less by polishing the inner surface of the vessel, is deteriorated by a reaction with impurities, including trace isolated iron and water, caused by the coarse inner texture of the conventional vessel despite such processing treatment.
- an object of the present invention is to provide a method of storing NF 3 , causing no deterioration of NF 3 even upon long storage.
- the present invention provides a method of storing NF 3 gas using a chromium-molybdenum steel vessel manufactured through a DDI process.
- Gas used in a semiconductor process is required to have high purity in proportion to an increase in the degree of integration of semiconductors.
- a vessel for storing such gas should be strictly controlled.
- a vessel for use in the storage of highly pure gas is subjected to a polishing process to have an Ra of 10 ⁇ m or less so as to prevent the contamination of gas charged in the vessel by water and impure particles attached to the inner surface of the vessel, and is then subjected to washing and drying processes in a vacuum to remove impurities from the inner portion thereof.
- the storage vessel is strictly treated as above, it suffers because NF 3 charged therein is gradually acidified.
- NF 3 gas charged in a conventional manganese steel vessel is deteriorated into impurities including NO X and thus the acidity (pH) thereof increases
- NF 3 in a storage vessel manufactured using chromium-molybdenum steel, instead of manganese steel, through a DDI process can be maintained in a highly pure state without increasing the acidity thereof. That is, even though a conventional manganese steel vessel is precisely processed for the inner surface thereof and completely washed and dried, NF 3 gas stored therein deteriorates over time, thus forming acidic material. After all, an acidic pH is detected from the gas.
- NF 3 gas is charged in a chromium-molybdenum steel vessel manufactured using a DDI process, no contaminants are observed, and the gas is not deteriorated even upon storage for a long period of time.
- a chromium-molybdenum steel vessel is found to be suitable as a storage vessel of NF 3 gas. This is because chromium-molybdenum steel is used not in pipe form as in a general manganese steel vessel but in steel sheet form, to manufacture a chromium-molybdenum steel vessel using a DDI process.
- a chromium-molybdenum steel vessel which is different in vessel material and manufacturing process from a manganese steel vessel, has a uniform surface with an Ra of 5 ⁇ m or less even without additional inner treatment.
- the chromium-molybdenum steel vessel may preferably have an Ra less than 1 ⁇ m.
- NF 3 in the above vessel undesirably reacts with isolated iron exposed to the inner surface of the gaps of the vessel to produce iron fluoride, which is then catalyzed to accelerate the decomposition of NF 3 , thus increasing the amount of N 2 O or acid component.
- the inner texture of the steel sheet becomes very dense through compression and shaping thereof, and thus the iron component is in almost the same state as if it were actually sintered.
- the inner surface of the chromium-molybdenum steel vessel is uniform and clear even without the inner treatment process. This is believed to be because chromium-molybdenum steel has fewer fine spaces, such as gaps of the inner surface, than manganese steel, thus easily removing inner impurities.
- Ammonia and fluorine gases were supplied to an ammonium hydrogen fluoride melt to prepare impure NF 3 gas.
- the gas thus prepared was refined to low-temperature highly pure NF 3 in a liquid phase, which was then collected in a gaseous phase in a storage vessel.
- 20 kg of the collected NF 3 gas was charged in each of a manganese steel vessel and a chromium-molybdenum steel vessel manufactured through a DDI process. Each vessel was allowed to stand at room temperature, and variation in the pH of NF 3 gas was measured over time.
- the manganese steel vessel containing 1.5 wt % of manganese and the chromium-molybdenum steel vessel containing 1.5 wt % of chromium and 0.5 wt % of molybdenum were used.
- N 2 O was analyzed using gas chromatography (Valco, POD detector).
- HNO 3 was analyzed by determining total acidity through neutralization titration using NaOH, subtracting the amount of HF from the total acidity, and then converting the resultant value to the amount of HNO 3 .
- the amount of HF was assayed using an F ion analyzer, and the presence of HNO 3 was confirmed by anion qualitative analysis using sulfuric acid and FeSO 4 .
- the manganese steel vessel having an Ra of 10 ⁇ m or less caused the decomposition of gas to be much lower than the manganese steel vessel having an Ra of 25 ⁇ m or more, however decomposition was still higher than in the chromium-molybdenum steel vessel manufactured using a DDI process.
- the present invention provides a method of storing NF 3 Therefore, NF 3 gas stored in this way according to the method of the present invention does not deteriorate even after two years or more have passed.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Metallurgy (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Inorganic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Clinical Laboratory Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
- Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
Abstract
The method of storing nitrogen trifluoride includes storing nitrogen trifluoride in a chromium-molybdenum steel vessel manufactured through a deep drawing ironing process. Nitrogen trifluoride stored in this way according to the method of this invention does not deteriorate even after two years or more have passed.
Description
- Not applicable.
- Not applicable.
- Not applicable.
- The present invention relates, generally, to a method of storing nitrogen trifluoride (NF3), and more particularly, to a method of storing NF3 gas, using a chromium-molybdenum steel vessel manufactured through a deep drawing ironing (DDI) process.
- In metal sheeting, a process of manufacturing a cylindrical vessel having a closed bottom using a drawing die is referred to as a DDI process.
- A machining tool comprising one pair of upper and lower pieces (punch and die) made of carbon tool steel or alloy tool steel is called the drawing die. The die is mounted to a press, and a sheet material is positioned in the press and fastened thereon. Then, when the punch presses the sheet material, the sheet material is drawn and thus shaped into the body of a cylindrical vessel in cup form such that a bottom surface and a side wall surface are integrated. The upper opening of the vessel thus produced is sealed and a valve is connected at an injection port thereof, to complete a high-pressure vessel for gas storage.
- The DDI process is also referred to as plug drawing.
- NF3 gas is an expensive chemical serving as an etching agent for the fabrication of a semiconductor device. The NF3 gas may be prepared through the direct reaction of fluorine gas and ammonia, the reaction of ammonium hydrogenfluoride (NF4HF2) and fluorine gas, or the electrolysis of an ammonium hydrogenfluoride melt. Commonly, NF3 is supplied to users by being prepared as a highly pure liquid and then charged in a 20˜50 L vessel in a high-pressure gas state.
- In addition, since NF3 is used as an etching agent for the fabrication of a semiconductor device, it must have high purity of 99.99% or more.
- Presently, the semiconductor process requires NF3 gas having purity levels of 3 ppm or less N2, 3 ppm or less O2, 1 ppm or less CO2, 20 ppm or less CF4, 1 ppm or less H2O, 1 ppm or less N2O, and 1 ppm or less HF.
- Therefore, NF3, which is highly reactive gas, should be stored in a specific vessel so as not to be deteriorated during storage or circulation.
- As a vessel for storing NF3 gas, a manganese steel vessel has been conventionally used. The manganese steel vessel is manufactured by subjecting a pipe formed of manganese steel containing 0.5˜1.5% manganese to a shaping process using heat to produce a cylindrical sealing vessel, and then conducting polishing and washing of the vessel thus produced.
- The manganese steel vessel, which is a general NF3 storage vessel, may be used after a polishing process has been conducted on the inner surface of the vessel, to realize inner surface roughness (Ra) of 10 μm or less, and washing and drying of the vessel have been conducted in a vacuum to completely remove inner impurities.
- However, even though the manganese steel vessel is processed to have an Ra of 10 μm or less without inner impurities, NF3 stored therein becomes acidic over time, resulting in deteriorated NF3.
- Although the exact mechanism for deterioration of NF3 has not been determined, it is inferred to result from the negative effects of impurities, that is, iron oxide (FeXOY), water, and oxygen, present in the vessel. The acidification was confirmed to be mainly caused by nitric acid.
- The following reaction shows the deterioration pathway of NF3 to nitric acid in the storage vessel.
2NF3+Fe2O3+H2O+O2→2HNO3+2FeF3
2NF3+2FeO+H2O+(3/2)O2→2HNO3+2FeF3 - In the acceptable NF3 standard, which is flowed by NF3 gas manufacturers and users at present, only HF acidity is determined, and acidity due to nitric acid is not determined, thus nitric acid is difficult to control.
- Further, since nitric acid is detected from NF3 stored in the manganese steel vessel, the vessel used is regarded as unsuitable for storage of NF3.
- Therefore, the development of a method of storing NF3, which does not cause deterioration of NF3 upon lengthy storage, is urgently required by NF3 users and manufacturers.
- Leading to the present invention, intensive and thorough research on NF3 storage methods resulted in the finding that NF3 stored in a chromium-molybdenum steel vessel manufactured through a DDI process does not deteriorate even after a long time elapses, although NF3, which is stored in a conventional manganese steel vessel having an Ra of 10 μm or less by polishing the inner surface of the vessel, is deteriorated by a reaction with impurities, including trace isolated iron and water, caused by the coarse inner texture of the conventional vessel despite such processing treatment.
- Accordingly, an object of the present invention is to provide a method of storing NF3, causing no deterioration of NF3 even upon long storage.
- The present invention provides a method of storing NF3 gas using a chromium-molybdenum steel vessel manufactured through a DDI process. Gas used in a semiconductor process is required to have high purity in proportion to an increase in the degree of integration of semiconductors. Thus, a vessel for storing such gas should be strictly controlled. Generally, a vessel for use in the storage of highly pure gas is subjected to a polishing process to have an Ra of 10 μm or less so as to prevent the contamination of gas charged in the vessel by water and impure particles attached to the inner surface of the vessel, and is then subjected to washing and drying processes in a vacuum to remove impurities from the inner portion thereof. However, even though the storage vessel is strictly treated as above, it suffers because NF3 charged therein is gradually acidified.
- The present inventors have observed that NF3 gas charged in a conventional manganese steel vessel is deteriorated into impurities including NOX and thus the acidity (pH) thereof increases, whereas NF3 in a storage vessel manufactured using chromium-molybdenum steel, instead of manganese steel, through a DDI process, can be maintained in a highly pure state without increasing the acidity thereof. That is, even though a conventional manganese steel vessel is precisely processed for the inner surface thereof and completely washed and dried, NF3 gas stored therein deteriorates over time, thus forming acidic material. After all, an acidic pH is detected from the gas. However, when NF3 gas is charged in a chromium-molybdenum steel vessel manufactured using a DDI process, no contaminants are observed, and the gas is not deteriorated even upon storage for a long period of time.
- Therefore, such a chromium-molybdenum steel vessel is found to be suitable as a storage vessel of NF3 gas. This is because chromium-molybdenum steel is used not in pipe form as in a general manganese steel vessel but in steel sheet form, to manufacture a chromium-molybdenum steel vessel using a DDI process. In particular, a chromium-molybdenum steel vessel, which is different in vessel material and manufacturing process from a manganese steel vessel, has a uniform surface with an Ra of 5 μm or less even without additional inner treatment. Moreover, in the case where the inner surface of the chromium-molybdenum steel vessel is treated, the chromium-molybdenum steel vessel may preferably have an Ra less than 1 μm.
- Even though a manganese steel vessel manufactured using a manganese steel pipe undergoes thorough inner surface treatment, impurities such as water or particles are difficult to completely remove from very fine gaps of the vessel. Further, NF3 in the above vessel undesirably reacts with isolated iron exposed to the inner surface of the gaps of the vessel to produce iron fluoride, which is then catalyzed to accelerate the decomposition of NF3, thus increasing the amount of N2O or acid component.
- On the other hand, in a vessel manufactured using a chromium-molybdenum steel sheet through a DDI process, the inner texture of the steel sheet becomes very dense through compression and shaping thereof, and thus the iron component is in almost the same state as if it were actually sintered. Moreover, the inner surface of the chromium-molybdenum steel vessel is uniform and clear even without the inner treatment process. This is believed to be because chromium-molybdenum steel has fewer fine spaces, such as gaps of the inner surface, than manganese steel, thus easily removing inner impurities.
- Further, as the amounts of isolated iron and trace impurities are decreased, NF3 gas is prevented from decomposition. A better understanding of the present invention may be obtained through the following examples which are set forth to illustrate, but are not to be construed as the limit of the present invention.
- Ammonia and fluorine gases were supplied to an ammonium hydrogen fluoride melt to prepare impure NF3 gas. The gas thus prepared was refined to low-temperature highly pure NF3 in a liquid phase, which was then collected in a gaseous phase in a storage vessel. 20 kg of the collected NF3 gas was charged in each of a manganese steel vessel and a chromium-molybdenum steel vessel manufactured through a DDI process. Each vessel was allowed to stand at room temperature, and variation in the pH of NF3 gas was measured over time. As such, the manganese steel vessel containing 1.5 wt % of manganese and the chromium-molybdenum steel vessel containing 1.5 wt % of chromium and 0.5 wt % of molybdenum were used. N2O was analyzed using gas chromatography (Valco, POD detector). In addition, HNO3 was analyzed by determining total acidity through neutralization titration using NaOH, subtracting the amount of HF from the total acidity, and then converting the resultant value to the amount of HNO3. The amount of HF was assayed using an F ion analyzer, and the presence of HNO3 was confirmed by anion qualitative analysis using sulfuric acid and FeSO4. The results are given in Tables 1 and 2 below, in which an Ra is a value measured on the inner surface of the vessel.
TABLE 1 Acidity of Gas in Storage Vessel Storage Vessel Storage Amount (kg) pH (Color Test) Manganese Steel 20 pH 7 ---> pH 3 (47L, Ra: 25 μm) (after 2 days) Manganese Steel 20 pH 7 --> pH 5 (47L, Ra: 10 μm) (after 6 months) Chromium-Molybdenum 20 pH 7 --> pH 7 Steel (DDI) (after 2 years)
*manganese steel: 1.5 wt % of manganese
chromium-molybdenum steel: 1.5 wt % of chromium, and 0.5 wt % of molybdenum
-
TABLE 2 Gas Component after 6 Months HF HNO3 N2O pH Storage Vessel (ppm) (ppm) (ppm) (Color Test) Manganese Steel 0.148 3.339 1 3 (Ra: 25 μm) Manganese Steel 0.022 1.816 Trace 5 (Ra: 10 μm) Chromium-Molybdenum 0.004 0.932 No Detection 7 Steel (DDI)
*manganese steel: 1.5 wt % of manganese
chromium-molybdenum steel: 1.5 wt % of chromium, and 0.5 wt % of molybdenum
- Although acid was detected over time in the manganese steel vessel, no variation was observed in the chromium-molybdenum steel vessel for a period of time of 2 years or longer. Further, the manganese steel vessel having an Ra of 10 μm or less caused the decomposition of gas to be much lower than the manganese steel vessel having an Ra of 25 μm or more, however decomposition was still higher than in the chromium-molybdenum steel vessel manufactured using a DDI process.
- As the result of gas component analysis in Table 2, the amounts of nitric acid and fluoric acid slightly increased in the gas charged in the manganese steel vessel, and thus the color indicating pH changed. It should be noted that the amount of N2O in the gas stored in the manganese steel vessel increased over time, whereas the gas stored in the chromium-molybdenum steel vessel subjected to DDI did not deteriorate, even after a long time, and maintained its highly pure state. Therefore, in the present invention, a vessel formed of chromium-molybdenum steel containing 1.5˜2.0 wt % of chromium and 0.2˜0.5 wt % of molybdenum is confirmed to be suitable for use in storing NF3.
- As described hereinbefore, the present invention provides a method of storing NF3 Therefore, NF3 gas stored in this way according to the method of the present invention does not deteriorate even after two years or more have passed.
- Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
Claims (2)
1. A method of storing nitrogen trifluoride, comprising the steps of:
storing nitrogen trifluoride in a chromium-molybdenum steel vessel manufactured using a deep drawing ironing process.
2. The method as set forth in claim 2 , wherein the chromium-molybdenum steel vessel is comprised of chromium-molybdenum steel comprising 1.5˜2.0 wt % of chromium and 0.2˜0.5 wt % of molybdenum.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR10-2005-0050668 | 2005-06-14 | ||
KR1020050050668A KR100660444B1 (en) | 2005-06-14 | 2005-06-14 | Storage method of Nitrogen trifluoride |
Publications (1)
Publication Number | Publication Date |
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US20060280642A1 true US20060280642A1 (en) | 2006-12-14 |
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ID=37513684
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US11/293,782 Abandoned US20060280642A1 (en) | 2005-06-14 | 2005-12-05 | Method of storing nitrogen trifluoride |
Country Status (6)
Country | Link |
---|---|
US (1) | US20060280642A1 (en) |
JP (1) | JP2006349171A (en) |
KR (1) | KR100660444B1 (en) |
CN (1) | CN100460745C (en) |
DE (1) | DE102005060954B4 (en) |
IT (1) | ITBO20060030A1 (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4578113A (en) * | 1983-05-19 | 1986-03-25 | Union Carbide Corporation | High strength steel |
US5133928A (en) * | 1989-10-28 | 1992-07-28 | Chesterfield Cylinders Limited | Cylinder body of a steel composition |
US20050006011A1 (en) * | 2002-02-15 | 2005-01-13 | Benteler Automobiltechnik Gmbh | Use of a steel alloy for making tubes to produce compressed gas containers or for making formed structures in light weight steel construction |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE737556C (en) * | 1935-01-06 | 1943-07-19 | Hoesch Ag | Chromium-molybdenum-iron alloy for corrosion-resistant objects, the production of which requires a high level of deep-drawing ability |
JP2927914B2 (en) * | 1990-08-31 | 1999-07-28 | 三井化学株式会社 | Method for producing nitrogen trifluoride gas |
JP3068216B2 (en) * | 1990-12-28 | 2000-07-24 | 東北特殊鋼株式会社 | High cold forging electromagnetic stainless steel |
JP2933826B2 (en) * | 1994-07-05 | 1999-08-16 | 川崎製鉄株式会社 | Chromium steel sheet excellent in deep drawing formability and secondary work brittleness and method for producing the same |
TW336257B (en) * | 1996-01-30 | 1998-07-11 | Daido Hoxan Inc | A method of carburizing austenitic stainless steel and austenitic stainless steel products obtained thereby |
JP3116038B2 (en) * | 1999-03-10 | 2000-12-11 | 三井化学株式会社 | Inner surface treatment method for high pressure gas container |
JP4114910B2 (en) * | 2000-11-30 | 2008-07-09 | 現代自動車株式会社 | Shift control method for automatic transmission for vehicle |
RU2182556C1 (en) * | 2001-09-28 | 2002-05-20 | Зао "Астор-Электроникс" | Method of obtaining nitrogen trifluoride |
KR100428906B1 (en) * | 2001-11-05 | 2004-04-29 | 주식회사 소디프신소재 | Method for preparing of filling cylinder of highly pure nitrogen trifluoride(nf3) by treating the inner side of filling cylinder and filling cylinder prepared by the method |
JP2003232495A (en) * | 2002-02-07 | 2003-08-22 | Mitsui Chemicals Inc | Charged high-purity high-pressure gas |
JP3816841B2 (en) * | 2002-06-25 | 2006-08-30 | 日本パイオニクス株式会社 | Purifying agent and purifying method for gas containing nitrogen fluoride |
JP3107715U (en) * | 2004-09-13 | 2005-02-03 | 中国工業株式会社 | High pressure gas container |
-
2005
- 2005-06-14 KR KR1020050050668A patent/KR100660444B1/en active IP Right Grant
- 2005-11-25 CN CNB2005100482999A patent/CN100460745C/en not_active Expired - Fee Related
- 2005-12-05 US US11/293,782 patent/US20060280642A1/en not_active Abandoned
- 2005-12-20 DE DE102005060954A patent/DE102005060954B4/en not_active Expired - Fee Related
-
2006
- 2006-01-17 IT IT000030A patent/ITBO20060030A1/en unknown
- 2006-06-09 JP JP2006161674A patent/JP2006349171A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4578113A (en) * | 1983-05-19 | 1986-03-25 | Union Carbide Corporation | High strength steel |
US5133928A (en) * | 1989-10-28 | 1992-07-28 | Chesterfield Cylinders Limited | Cylinder body of a steel composition |
US20050006011A1 (en) * | 2002-02-15 | 2005-01-13 | Benteler Automobiltechnik Gmbh | Use of a steel alloy for making tubes to produce compressed gas containers or for making formed structures in light weight steel construction |
Also Published As
Publication number | Publication date |
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CN100460745C (en) | 2009-02-11 |
CN1880830A (en) | 2006-12-20 |
DE102005060954A1 (en) | 2006-12-28 |
DE102005060954B4 (en) | 2008-07-31 |
KR20060130281A (en) | 2006-12-19 |
KR100660444B1 (en) | 2006-12-22 |
JP2006349171A (en) | 2006-12-28 |
ITBO20060030A1 (en) | 2006-12-15 |
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