CN112342489A - Passivation treatment method for iron container for storing electronic-grade carbon monoxide gas - Google Patents
Passivation treatment method for iron container for storing electronic-grade carbon monoxide gas Download PDFInfo
- Publication number
- CN112342489A CN112342489A CN202011068197.4A CN202011068197A CN112342489A CN 112342489 A CN112342489 A CN 112342489A CN 202011068197 A CN202011068197 A CN 202011068197A CN 112342489 A CN112342489 A CN 112342489A
- Authority
- CN
- China
- Prior art keywords
- gas
- carbon monoxide
- passivating
- equal
- container
- 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.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/80—After-treatment
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
The invention relates to a passivation treatment method for an iron container for storing electronic-grade carbon monoxide gas, belonging to the technical field of chemical industry. The method comprises the following steps: vacuumizing an iron container to be treated at 40-60 ℃, and then filling mixed gas of fluorine gas and inert gas until the pressure in the iron container is 0.05-0.1 MPa; then standing and passivating for 65-85h at 15-45 ℃; vacuumizing the passivated iron container, and filling high-purity inert gas to the pressure of 0.01-0.02MPa for replacement treatment; and (4) analyzing the components in the iron container after the replacement treatment, and finishing the passivation treatment when the contents of oxygen, nitrogen, hydrogen, carbon monoxide and carbon dioxide meet the requirements, or repeating the steps to perform the replacement treatment. The method can form a uniform passivation film on the inner surface of the iron packaging container filled with the electronic-grade carbon monoxide, and meets the storage and use requirements of the electronic-grade gas containing high-purity carbon monoxide.
Description
Technical Field
The invention relates to a passivation treatment method for an iron container for storing electronic-grade carbon monoxide gas, belonging to the technical field of chemical industry.
Background
Under certain conditions, carbon monoxide and iron react to generate carbonyl iron, so that trace carbonyl iron is inevitably produced in the long-term use process of the carbon monoxide steel packaging container under high pressure conditions, and the carbonyl iron enters a rear end use system along with electronic-grade carbon monoxide; carbonyl iron belongs to a high-toxicity article and can influence the use of carbon monoxide. For example, metallic iron is introduced during the chip processing process, which affects the performance of the chip.
At present, the hidden trouble that the carbon monoxide packaging container generates carbonyl iron in the long-term use process is not fundamentally solved.
Disclosure of Invention
In view of the above, the present invention aims to provide a passivation treatment method for an iron container for storing electronic grade carbon monoxide gas, wherein the method is simple and has good treatment effect.
In order to achieve the above object, the technical solution of the present invention is as follows.
A process for passivating a ferrous gas vessel storing electronic grade carbon monoxide, the process steps comprising:
(1) vacuumizing an iron container to be treated at 40-60 ℃ until the pressure is less than or equal to-0.095 MPa, and filling mixed gas of fluorine gas and inert gas until the pressure in the iron container is 0.05-0.1 MPa; wherein the volume content of the fluorine gas in the mixed gas of the fluorine gas and the inert gas is 40-80%;
(2) standing and passivating an iron container filled with mixed gas of fluorine gas and inert gas at 15-45 ℃ for 60-85 h;
(3) vacuumizing the passivated iron container until the pressure is less than or equal to-0.095 MPa, and filling high-purity inert gas until the pressure is 0.01-0.02MPa for replacement treatment;
(4) and (3) analyzing components in the iron container after the replacement treatment, finishing the passivation treatment when oxygen is less than or equal to 3ppmV, nitrogen is less than or equal to 3ppmV, hydrogen is less than or equal to 0.5ppmV, carbon monoxide is less than or equal to 0.5ppmV, and carbon dioxide is less than or equal to 0.5ppmV, otherwise, repeating the step (3) until the requirements are met.
Preferably, the fluorine gas and the inert gas in step (1) are of industrial grade.
Preferably, the flow rate of the mixed gas in the step (1) is 80-100L/min.
Preferably, the material of the iron container is 30 CrMo.
Preferably, in the step (1), the volume fraction of the fluorine gas in the mixed gas of the fluorine gas and the inert gas is 40 to 60%.
Preferably, in the step (2), the standing and passivating temperature is 30-45 ℃.
Preferably, in the step (2), the standing passivation time is 60 to 72 hours.
Preferably, in the step (2), the iron container is placed on a mixing machine and rolls for 20-30min at the rotating speed of 15-20m/h before standing and passivating.
Preferably, in the step (3), the purity of the high-purity inert gas is 99.999%.
Preferably, in the step (3), the flow rate of the high-purity inert gas is 5 to 100L/min.
Preferably, the inert gas and the high-purity inert gas are respectively helium or argon.
Advantageous effects
The method of the invention can form a layer of uniform passive film on the inner surface of the iron packaging container filled with the electronic grade carbon monoxide, thereby meeting the storage and use requirements of the electronic grade gas containing high-purity carbon monoxide. The content of carbonyl iron in the steel cylinder is less than or equal to 1 ppb.
The invention utilizes the reaction 2Fe +3F2→2FeF3Scientifically designing the technological conditions to form a layer on the inner surface of the steel cylinderThe uniform passivation film meets the storage and use requirements of the electronic grade gas containing high-purity carbon monoxide.
The invention can passivate the inner wall of the carbon monoxide packaging container, such as a steel cylinder, a Y tank, a tube bundle tank car, a tube bundle container, a tank car, a storage tank and the like, and has wide application range.
Detailed Description
The present invention will be described in further detail with reference to specific examples.
Example 1
In this embodiment, the iron container is a steel cylinder made of 30CrMo, and is made of alloy structural steel (alloy steel) from steel works.
A passivation treatment method for a ferrous gas container for storing electronic grade carbon monoxide comprises the following steps:
(1) evacuating an iron container to be treated until the pressure is less than or equal to-0.095 MPa, and filling mixed gas of fluorine gas and helium gas until the pressure in the iron container is 0.08 MPa; the volume content of the fluorine gas in the mixed gas of the fluorine gas and the helium gas is 40%; the flow rate of the mixed gas of fluorine gas and helium gas was 50L/min.
(2) Placing an iron container filled with mixed gas of fluorine gas and helium gas at 35 ℃ for standing and passivating for 72 hours; the steel cylinder forms a passivation layer on the surface after the process.
(3) Vacuumizing the passivated iron container until the pressure is less than or equal to-0.095 MPa, filling high-purity argon until the pressure is 0.015MPa, and performing replacement treatment, wherein the replacement treatment is repeated for 5 times; the flow rate of the high-purity helium gas is 50L/min; the purity of the high-purity helium gas is 99.999%.
(4) Analyzing the components in the iron container after the replacement treatment, wherein the oxygen is less than or equal to 3ppmV, the nitrogen is less than or equal to 3ppmV, the hydrogen is less than or equal to 0.5ppmV, the carbon monoxide is less than or equal to 0.5ppmV, and the carbon dioxide is less than or equal to 0.5ppmV, and finishing the passivation treatment.
And (3) carrying out gas phase component analysis on the passivated steel cylinder by using an inductively coupled plasma mass spectrometry (ICP-MS), wherein the result is shown in table 1, and the iron ion content in the steel cylinder is less than or equal to 1ppb through analysis.
Example 2
In this embodiment, the iron container is a steel cylinder made of 30CrMo, and is made of alloy steel from northeast special steel.
A passivation treatment method for a ferrous gas container for storing electronic grade carbon monoxide comprises the following steps:
(1) evacuating an iron container to be treated until the pressure is less than or equal to-0.095 MPa, and filling mixed gas of fluorine gas and helium gas until the pressure in the iron container is 0.05 MPa; the volume content of the fluorine gas in the mixed gas of the fluorine gas and the helium gas is 60%; the flow rate of the mixed gas of fluorine gas and helium gas was 5L/min.
(2) Placing an iron container filled with mixed gas of fluorine gas and helium gas at 15 ℃ for standing and passivating for 85 hours; the steel cylinder forms a passivation layer on the surface after the process.
(3) Vacuumizing the passivated iron container until the pressure is less than or equal to-0.095 MPa, filling high-purity argon until the pressure is 0.02MPa, and performing replacement treatment, wherein the replacement treatment is repeated for 4 times; the flow rate of the high-purity helium gas is 5L/min; the purity of the high-purity helium gas is 99.999%.
(4) Analyzing the components in the iron container after the replacement treatment, wherein the oxygen is less than or equal to 3ppmV, the nitrogen is less than or equal to 3ppmV, the hydrogen is less than or equal to 0.5ppmV, the carbon monoxide is less than or equal to 0.5ppmV, and the carbon dioxide is less than or equal to 0.5ppmV, and finishing the passivation treatment.
And (3) carrying out gas phase component analysis on the passivated steel cylinder by using an inductively coupled plasma mass spectrometry (ICP-MS), wherein the result is shown in table 1, and the iron ion content in the steel cylinder is less than or equal to 1ppb through analysis.
Example 3
In this embodiment the iron container is the steel bottle, and the material is 30CrMo, and the classification is the alloy steel, comes from big metallurgical steel factory.
A passivation treatment method for a ferrous gas container for storing electronic grade carbon monoxide comprises the following steps:
(1) evacuating an iron container to be treated until the pressure is less than or equal to-0.095 MPa, and filling mixed gas of fluorine gas and helium gas until the pressure in the iron container is 0.1 MPa; the volume content of the fluorine gas in the mixed gas of the fluorine gas and the helium gas is 50%; the flow rate of the mixed gas of fluorine gas and helium gas was 100L/min.
(2) Placing an iron container filled with mixed gas of fluorine gas and helium gas at 45 ℃ for standing and passivating for 65 hours; the steel cylinder forms a passivation layer on the surface after the process.
(3) Vacuumizing the passivated iron container until the pressure is less than or equal to-0.095 MPa, filling high-purity argon until the pressure is 0.01MPa, performing replacement treatment, and repeating the replacement treatment for 6 times; the flow rate of the high-purity helium gas is 100L/min; the purity of the high-purity helium gas is 99.999%.
(4) Analyzing the components in the iron container after the replacement treatment, wherein the oxygen is less than or equal to 3ppmV, the nitrogen is less than or equal to 3ppmV, the hydrogen is less than or equal to 0.5ppmV, the carbon monoxide is less than or equal to 0.5ppmV, and the carbon dioxide is less than or equal to 0.5ppmV, and finishing the passivation treatment.
And (3) carrying out gas phase component analysis on the passivated steel cylinder by using an inductively coupled plasma mass spectrometry (ICP-MS), wherein the result is shown in table 1, and the iron ion content in the steel cylinder is less than or equal to 1ppb through analysis.
Example 4
In this embodiment the iron container is the steel bottle, and the material is 30CrMo, and the classification is the alloy steel, comes from big metallurgical steel factory.
A passivation treatment method for a ferrous gas container for storing electronic grade carbon monoxide comprises the following steps:
(1) evacuating an iron container to be treated until the pressure is less than or equal to-0.095 MPa, and filling mixed gas of fluorine gas and helium gas until the pressure in the iron container is 0.09 MPa; the volume content of the fluorine gas in the mixed gas of the fluorine gas and the helium gas is 55%; the flow rate of the mixed gas of fluorine gas and helium gas was 5L/min.
(2) Placing an iron container filled with mixed gas of fluorine gas and helium gas at 25 ℃ for standing and passivating for 85 hours; the steel cylinder forms a passivation layer on the surface after the process.
(3) Vacuumizing the passivated iron container until the pressure is less than or equal to-0.095 MPa, filling high-purity argon until the pressure is 0.01MPa, performing replacement treatment, and repeating the replacement treatment for 6 times; the flow rate of the high-purity helium gas is 80L/min; the purity of the high-purity helium gas is 99.999%.
(4) Analyzing the components in the iron container after the replacement treatment, wherein the oxygen is less than or equal to 3ppmV, the nitrogen is less than or equal to 3ppmV, the hydrogen is less than or equal to 0.5ppmV, the carbon monoxide is less than or equal to 0.5ppmV, and the carbon dioxide is less than or equal to 0.5ppmV, and finishing the passivation treatment.
And (3) carrying out gas phase component analysis on the passivated steel cylinder by using an inductively coupled plasma mass spectrometry (ICP-MS), wherein the result is shown in table 1, and the iron ion content in the steel cylinder is less than or equal to 1ppb through analysis.
TABLE 1
In Table 1, steel cylinder No. 1770226 is a steel cylinder processed by the method of example 1, steel cylinder No. 1972205 is a steel cylinder processed by the method of example 2, and steel cylinder No. Q1900331 is a steel cylinder processed by the method of example 3. Cylinder number 1972204 is the cylinder treated using the method of example 4.
The test data show that the impurity element content is very low after the treatment of the invention, which indicates that the method not only effectively avoids producing trace carbonyl iron in steel cylinders, but also produces little other impurity elements.
After the cylinder was used for three months, the gas phase composition in the cylinder was again analyzed, and the analysis results were similar to those of table 1.
In summary, the invention includes but is not limited to the above embodiments, and any equivalent replacement or local modification made under the spirit and principle of the invention should be considered as being within the protection scope of the invention.
Claims (10)
1. A passivation treatment method for an iron container for storing electronic-grade carbon monoxide gas is characterized by comprising the following steps: the method comprises the following steps:
(1) vacuumizing an iron container to be treated at 40-60 ℃ until the pressure is less than or equal to-0.095 MPa, and filling mixed gas of fluorine gas and inert gas until the pressure in the iron container is 0.05-0.1 MPa; wherein the volume content of the fluorine gas in the mixed gas of the fluorine gas and the inert gas is 40-80%;
(2) standing and passivating an iron container filled with mixed gas of fluorine gas and inert gas at 15-45 ℃ for 60-85 h;
(3) vacuumizing the passivated iron container until the pressure is less than or equal to-0.095 MPa, and filling high-purity inert gas until the pressure is 0.01-0.02MPa for replacement treatment;
(4) and (3) analyzing components in the iron container after the replacement treatment, finishing the passivation treatment when oxygen is less than or equal to 3ppmV, nitrogen is less than or equal to 3ppmV, hydrogen is less than or equal to 0.5ppmV, carbon monoxide is less than or equal to 0.5ppmV, and carbon dioxide is less than or equal to 0.5ppmV, otherwise, repeating the step (3) until the requirements are met.
2. The process of passivating a ferrous storage container for electronic grade carbon monoxide gas as recited in claim 1, wherein: in the step (1), the fluorine gas and the inert gas are of industrial grade.
3. The process of passivating a ferrous storage container for electronic grade carbon monoxide gas as recited in claim 1, wherein: the flow rate of the mixed gas in the step (1) is 80-100L/min.
4. The process of passivating a ferrous storage container for electronic grade carbon monoxide gas as recited in claim 1, wherein: in the step (1), the volume fraction of the fluorine gas in the mixed gas of the fluorine gas and the inert gas is 40 to 60%.
5. The process of passivating a ferrous storage container for electronic grade carbon monoxide gas as recited in claim 1, wherein: in the step (2), the standing and passivating temperature is 30-45 ℃, and the standing and passivating time is 60-72 hours.
6. The process of passivating a ferrous storage container for electronic grade carbon monoxide gas as recited in claim 1, wherein: in the step (2), the iron container is placed on a mixing machine and rolls for 20-30min at the rotating speed of 15-20m/h before standing and passivating.
7. The process of passivating a ferrous storage container for electronic grade carbon monoxide gas as recited in claim 1, wherein: in the step (3), the purity of the high-purity inert gas is 99.999%.
8. The process of passivating a ferrous storage container for electronic grade carbon monoxide gas as recited in claim 1, wherein: in the step (3), the flow rate of the high-purity inert gas is 5-100L/min.
9. The process of passivating a ferrous storage container for electronic grade carbon monoxide gas as recited in claim 1, wherein: the iron container is made of 30 CrMo.
10. The process of passivating a ferrous storage container for electronic grade carbon monoxide gas as recited in claim 1, wherein: the inert gas and the high-purity inert gas are respectively helium or argon.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011068197.4A CN112342489A (en) | 2020-10-08 | 2020-10-08 | Passivation treatment method for iron container for storing electronic-grade carbon monoxide gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011068197.4A CN112342489A (en) | 2020-10-08 | 2020-10-08 | Passivation treatment method for iron container for storing electronic-grade carbon monoxide gas |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112342489A true CN112342489A (en) | 2021-02-09 |
Family
ID=74361633
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011068197.4A Pending CN112342489A (en) | 2020-10-08 | 2020-10-08 | Passivation treatment method for iron container for storing electronic-grade carbon monoxide gas |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112342489A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114321698A (en) * | 2021-12-30 | 2022-04-12 | 大连科利德光电子材料有限公司 | Steel cylinder for storing electronic-grade nitric oxide and machining method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4008163A (en) * | 1970-04-14 | 1977-02-15 | Ingels Glenn R | Method of preparing a saturated fluid mixture |
| CN102517540A (en) * | 2011-12-20 | 2012-06-27 | 广东华南特种气体研究所有限公司 | Passivation method of excimer laser gas configuration device |
| CN106064807A (en) * | 2016-07-14 | 2016-11-02 | 合肥正帆电子材料有限公司 | Electron level arsenic hydride, hydrogen phosphide and the passivation device of mixed gas steel cylinder thereof |
| CN111139428A (en) * | 2019-12-30 | 2020-05-12 | 中船重工（邯郸）派瑞特种气体有限公司 | Passivation treatment method for steel cylinder for storing fluorine-containing compound electronic grade gas |
-
2020
- 2020-10-08 CN CN202011068197.4A patent/CN112342489A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4008163A (en) * | 1970-04-14 | 1977-02-15 | Ingels Glenn R | Method of preparing a saturated fluid mixture |
| CN102517540A (en) * | 2011-12-20 | 2012-06-27 | 广东华南特种气体研究所有限公司 | Passivation method of excimer laser gas configuration device |
| CN106064807A (en) * | 2016-07-14 | 2016-11-02 | 合肥正帆电子材料有限公司 | Electron level arsenic hydride, hydrogen phosphide and the passivation device of mixed gas steel cylinder thereof |
| CN111139428A (en) * | 2019-12-30 | 2020-05-12 | 中船重工（邯郸）派瑞特种气体有限公司 | Passivation treatment method for steel cylinder for storing fluorine-containing compound electronic grade gas |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114321698A (en) * | 2021-12-30 | 2022-04-12 | 大连科利德光电子材料有限公司 | Steel cylinder for storing electronic-grade nitric oxide and machining method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112342489A (en) | Passivation treatment method for iron container for storing electronic-grade carbon monoxide gas | |
| WO2019198325A1 (en) | Method for producing tetrahydroborate and tetrahydroborate | |
| US7500497B2 (en) | Method of filling compressed-gas containers with gas | |
| CN111139428A (en) | Passivation treatment method for steel cylinder for storing fluorine-containing compound electronic grade gas | |
| CN109311667B (en) | Hydrogen sulfide mixture, method for producing same, and filled container | |
| CN110606490A (en) | Synthesis and purification method of high-purity silicon tetrafluoride | |
| CN100484662C (en) | Metal micron nano particle cladding process | |
| JP2020500104A (en) | How to remove moisture from hydrazine | |
| CN112992457B (en) | Permanent magnet material and preparation method thereof | |
| CN113213507A (en) | Method for removing impurity ions in liquid ammonia | |
| CN101922004A (en) | Method for treating inner wall of high-pressure seamless steel gas cylinder | |
| CN106770610A (en) | A kind of abundance measurement method of boron 10 in boron and compound | |
| CN111097915B (en) | Method for preparing low-oxygen high-quality hydrogenated and dehydrogenated titanium powder | |
| EP2050528B1 (en) | Atmosphere for metal atomization including gaseous hydride | |
| CN107904425B (en) | Preparation method of nitrided ferrovanadium | |
| JP7111581B2 (en) | High-purity raw material gas supply method and high-purity raw material gas supply equipment | |
| CN213422547U (en) | Batch nondestructive leak detection device for air-tight packaged integrated circuits | |
| CN111999008B (en) | Batch nondestructive leakage detection method and device for airtight packaged integrated circuits | |
| CN116213718B (en) | Method for preparing high-quality low-oxygen-content titanium or titanium alloy powder based on vapor deposition | |
| CN100350069C (en) | Method for nitriding stainless steel parts for steam turbine and gasturbine | |
| CN108690917A (en) | A kind of Degassing Technology of Al Alloys | |
| CN103978221B (en) | A kind of oxide-dispersed alloy raw powder's production technology | |
| CN100460745C (en) | Method of storing nitrogen trifluoride | |
| CN116359321A (en) | Method for measuring trace impurity content in nitrous oxide | |
| CN113549731B (en) | Method for reducing aluminum killed steel inclusions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: 057550 No. five Weir Road, chemical industry gathering area, Feixiang District, Handan, Hebei, 1 Applicant after: China shipbuilding (Handan) Perry Special Gas Co.,Ltd. Address before: No.1 Weiwu Road, chemical industry gathering area, Feixiang County, Handan City, Hebei Province Applicant before: PERIC SPECIAL GASES Co.,Ltd. |
|
| CB02 | Change of applicant information | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20210209 |
|
| WD01 | Invention patent application deemed withdrawn after publication |