CN107267704B - Inoculant containing nano silicon carbide for nodular cast iron and vermicular cast iron and preparation method thereof - Google Patents
Inoculant containing nano silicon carbide for nodular cast iron and vermicular cast iron and preparation method thereof Download PDFInfo
- Publication number
- CN107267704B CN107267704B CN201710531600.4A CN201710531600A CN107267704B CN 107267704 B CN107267704 B CN 107267704B CN 201710531600 A CN201710531600 A CN 201710531600A CN 107267704 B CN107267704 B CN 107267704B
- Authority
- CN
- China
- Prior art keywords
- cast iron
- silicon carbide
- nano
- sic
- particles
- 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.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/08—Manufacture of cast-iron
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/10—Making spheroidal graphite cast-iron
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention discloses an inoculant containing nano silicon carbide for nodular cast iron and vermicular cast iron and a preparation method thereof, relating to the technical field of inoculants; the invention adopts the planetary ball milling technology to compound the SiC powder with nanoscale and micron-scale, siC of the nano particles is attached to the SiC surface of the micron particles, and the micron-scale silicon carbide particles with larger size are used to carry a large amount of nano silicon carbide particles, thereby preparing a novel composite nano silicon carbide inoculant, and the obtained composite powder is made into cored wires by adopting the cored wire technology; the inoculation treatment is carried out on the nodular cast iron molten iron and the vermicular cast iron molten iron by adopting a wire feeding method, so that a good inoculation effect is obtained; the invention improves the quality of nodular cast iron and the process stability of the vermicular cast iron, and simultaneously reduces the consumption of the nano SiC, thereby reducing the production cost.
Description
Technical Field
The invention relates to an inoculant containing nano silicon carbide for nodular cast iron and vermicular cast iron and a preparation method thereof, belonging to the technical field of inoculants.
Background
The nodular cast iron is cast iron with spheroidal graphite structure obtained by adding an inoculant and a nodulizer into molten iron for inoculation and nodulizing, is a high-strength cast iron material, has comprehensive performance close to that of steel, is an ideal material for replacing steel with iron at present, and is commonly used for producing parts with complex stress and high requirements on strength, toughness, wear resistance and the like. The vermicular cast iron is cast iron with vermicular graphite structure obtained by adding an inoculant and a vermiculizer into molten iron for inoculation and vermicular treatment. The vermicular graphite cast iron has the performance between that of gray iron and ductile iron, not only has the strength similar to that of nodular cast iron, but also has the heat conduction and casting performance similar to that of the gray cast iron, and has better plasticity and fatigue performance than the gray cast iron, thereby being a good structural material with good development prospect and having good application prospect on parts such as engine cylinder bodies, cylinder covers, cylinder liners and the like of a new generation of heavy trucks.
The research shows that the nanometer silicon carbide as the inoculant can obviously improve the structure of the nodular cast iron, reduce the size of graphite nodules, improve the spheroidization rate of the graphite, and the like. However, the problem that the agglomeration of the nano SiC material is not easy to disperse is not solved ideally, and the practical application of the nano silicon carbide in the traditional casting field is restricted. The element control window for producing the vermicular iron molten iron is very narrow, and graphite vermicularizing is difficult, so that strict component and process control are required in the production process to ensure the stability of the vermicularizing effect. In addition, the amount of nano SiC added in the previous research is large, and the price of nano SiC is high, so that the method is not ideal in economy.
Disclosure of Invention
Aiming at the problems, the invention provides an inoculant for nodular cast iron and vermicular cast iron containing nano silicon carbide and a preparation method thereof.
The inoculant for nodular cast iron and vermicular cast iron containing nano silicon carbide is prepared by compounding nano silicon carbide and micron silicon carbide, carrying a large amount of nano silicon carbide particles by using micron silicon carbide particles with larger sizes, attaching SiC of the nano particles to the SiC surfaces of the micron particles, and adding a plurality of nano particles into molten iron in a concentrated manner in a micro area in the inoculation treatment process.
The invention relates to a preparation method of inoculant for nodular cast iron and vermicular cast iron containing nano silicon carbide, which comprises the following steps:
the method comprises the following steps: preparing materials:
drying silicon carbide with the average grain size of 50nm and the average grain size of 10 microns in a drying box for 12-48 hours at the drying temperature of 100 ℃, and then weighing the silicon carbide with the average grain size of 50nm and the average grain size of 10 microns respectively for batching, wherein the mass fraction of the nano SiC is 0.1-50 wt%;
step two: mixing:
mixing materials by adopting a planetary ball mill, wherein the revolution speed is 200-400 r/min, the ball milling time is 1-3 hours, standing and cooling for 10 minutes after the ball milling is finished, taking out the mixed powder, and drying and storing;
step three: preparing a wire:
and (3) preparing the mixed powder into a cored wire with the diameter of 5mm by using a cored wire machine.
Compared with the prior art, the invention has the beneficial effects that: the quality of the nodular cast iron and the process stability of the vermicular cast iron are improved, and the consumption of the nano SiC is reduced, so that the production cost is reduced.
Description of the drawings:
for ease of illustration, the invention is described in detail by the following detailed description and the accompanying drawings.
Fig. 1 is a SEM picture of a nano-SiC composite inoculant wherein (a) (b) is a composite nano-SiC inoculant having a nano-SiC content of 1wt.%, (c) (d) is a composite nano-SiC inoculant having a nano-SiC content of 10wt.%, (e) (f) is a composite nano-SiC inoculant having a nano-SiC content of 20 wt.%;
FIG. 2 shows that composite nano SiC with the nano SiC content of 1wt.% inoculates a metallographic structure of nodular cast iron, wherein (a) is the metallographic structure before nitric acid and ethanol corrosion, and (b) is the metallographic structure after nitric acid and ethanol corrosion;
FIG. 3 is a composite nano SiC inoculated vermicular cast iron metallographic structure with 1wt.% nano SiC content, wherein (a) is metallographic phase with a magnification of 50 times and (b) is metallographic phase with a magnification of 100 times;
FIG. 4 shows that composite nano SiC with 10wt.% nano SiC content inoculates a metallographic structure of nodular cast iron, wherein (a) is the metallographic structure before nitric acid and ethanol corrosion, and (b) is the metallographic structure after nitric acid and ethanol corrosion;
FIG. 5 is a composite nano SiC inoculated vermicular cast iron metallographic structure with a nano SiC content of 10wt.%, wherein (a) is a metallographic phase with a magnification of 50 times, and (b) is a metallographic phase with a magnification of 100 times;
FIG. 6 shows that composite nano SiC with 20wt.% nano SiC content inoculates a metallographic structure of nodular cast iron, wherein (a) is the metallographic structure before nitric acid and ethanol corrosion, and (b) is the metallographic structure after nitric acid and ethanol corrosion;
fig. 7 shows that composite nano SiC with 20wt.% nano SiC content inoculates a metallographic structure of vermicular cast iron, wherein (a) is a 50-fold metallographic phase and (b) is a 100-fold metallographic phase.
The specific implementation mode is as follows:
in order that the objects, aspects and advantages of the invention will become more apparent, the invention will be described by way of example only, and in connection with the accompanying drawings. It is to be understood that such description is merely illustrative and not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.
As shown in fig. 1, in the present embodiment, a planetary ball milling process is used to compound a powder with an average particle size of 50nmSiC and a powder with an average particle size of 10 μmSiC to prepare a composite nano silicon carbide inoculant, and a core-spun wire with a diameter of 5mm is prepared by using a core-spun wire machine. The method is characterized in that: the SiC nanoparticles attached to the surface of the 10 mu m SiC nanoparticles in the composite nano silicon carbide inoculant increase first and then reach the limit along with the increase of the mass ratio of the nanoparticles.
Silicon carbide itself has a high melting point, much higher than the temperature of molten iron, and it does not "melt" in molten iron to a melting point, but "dissolves" due to atomic migration caused by concentration differences. The dissolved silicon carbide forms a region with higher carbon equivalent around the particles, thus promoting the precipitation of graphite, and the newly generated graphite cores effectively reduce the chilling tendency of the casting and obviously play a role in refining the matrix structure. In addition, the silicon carbide forms C atomic groups around the silicon carbide when being dissolved, the atomic groups can form primary graphite in the crystallization process, the primary graphite can become a very active graphite crystal core, and more nucleation particles are added on the basis of heterogeneous nucleation of the original molten iron.
When single nanometer level cubic silicon carbide particle is added into molten iron, the action mechanism of the nanometer level cubic silicon carbide particle is similar to that of the traditional SiC inoculant, but the nanometer level cubic silicon carbide particle has extremely small size, large specific surface area and large surface energy, so that the inoculation nucleation capability of the nanometer level cubic silicon carbide particle in a local micro-area is also very strong. This inoculation in the very small range caused by the nano-sized silicon carbide particles is referred to as "micro-inoculation".
Although the nano silicon carbide has strong inoculation capability, due to the small size, a single nano silicon carbide particle can only perform the inoculation nucleation effect on a small range around the nano silicon carbide particle, and if a plurality of independent nano silicon carbide particles are tightly distributed in a small area in molten iron, the precipitation and spheroidization capability of the graphite particles to the nano silicon carbide particles can generate a superposition effect. However, the nano SiC has small particle size, large surface atom proportion, large specific surface area, large surface energy due to lack of adjacent coordination atoms on the surface, and is in an energy unstable state, so that the agglomeration phenomenon is easy to occur, most of the nano SiC is agglomerated particles, and the number of single particles is small. And because the density of the silicon carbide is smaller and the average density of the agglomerated nano silicon carbide is smaller, the nano silicon carbide is easy to float in the inoculation treatment process, and the inoculation effect of the nano SiC is greatly weakened.
The composite nanometer silicon carbide utilizes micron-sized silicon carbide particles with larger sizes to carry a large number of nanometer silicon carbide particles, realizes the idea of adding a plurality of nanometer particles into molten iron in a concentrated manner in a micro area, so that the micro inoculation effect is superposed, and simultaneously, the micron-sized silicon carbide particles serving as main bodies have larger particle size, so that the action range is larger, the duration is longer, and the local inoculation effect of a larger area is more easily formed in the molten iron.
Example (b):
the first embodiment is as follows: the composite inoculant with the nano SiC content of 1wt.% inoculates nodular cast iron and vermicular cast iron:
drying silicon carbide with the average grain size of 50nm and the average grain size of 10 mu m for 24 hours, and then weighing the silicon carbide with the average grain size of 50nm and the average grain size of 10 mu m respectively for batching, wherein the mass fraction of the nano SiC is 1wt.%. Mixing materials by adopting a planetary ball mill, wherein the revolution speed is 300 revolutions, the ball milling time is 2 hours, standing and cooling for 10 minutes after the ball milling is finished, taking out the mixed powder, and drying and storing. And preparing the mixed powder into a cored wire with the diameter of 5mm by using a cored wire machine by using the composite inoculant with the nano SiC content of 1wt.%.
The prepared core-spun yarn is respectively inserted into spheroidized molten iron or vermicular molten iron for inoculation, and the addition amount of the inoculant is 0.05wt.%. The metallographic structure of the nodular cast iron obtained after inoculation is shown in figure 2, the tensile strength of the nodular cast iron is 358MPa, and the elongation is 6 percent; the metallographic structure of the vermicular cast iron obtained after inoculation is shown in figure 3, the tensile strength of the vermicular cast iron is 360MPa, and the elongation is 4%.
Example two: the composite inoculant with the nano SiC content of 10wt.% inoculates nodular cast iron and vermicular cast iron:
the technical scheme is the same as that of the first embodiment, except that the mass fraction of the nano SiC is 10wt.%.
The metallographic structure of the nodular cast iron obtained after inoculation is shown in figure 4, the tensile strength of the nodular cast iron is 398MPa, and the elongation is 10 percent; the metallographic structure of the vermicular cast iron obtained after inoculation is shown in figure 5, the tensile strength of the vermicular cast iron is 379MPa, and the elongation is 6%.
Example three: the composite inoculant with the nano SiC content of 20wt.% inoculates nodular cast iron and vermicular cast iron:
the technical scheme is the same as that of the first embodiment, except that the mass fraction of the nano SiC is 20wt.%.
The metallographic structure of the nodular cast iron obtained after inoculation is shown in FIG. 6, the tensile strength of the nodular cast iron is 384MPa, and the elongation is 9%; the metallographic structure of the vermicular cast iron obtained after inoculation is shown in fig. 7, the tensile strength of the vermicular cast iron is 367MPa, and the elongation is 5%.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.
Claims (2)
1. The inoculant for nodular cast iron and vermicular cast iron containing nano silicon carbide is characterized in that: the nano silicon carbide and the micron silicon carbide are compounded, a large number of nano silicon carbide particles are carried by micron silicon carbide particles with larger sizes, siC of nano particles is attached to the SiC surfaces of the micron particles, and a plurality of nano particles are concentrated in a micro area and added into molten iron in the inoculation treatment process.
2. The preparation method of the inoculant for the nodular cast iron and the vermicular cast iron containing the nano silicon carbide is characterized by comprising the following steps: the preparation method comprises the following steps:
the method comprises the following steps: preparing materials:
drying silicon carbide with the average grain size of 50nm and the average grain size of 10 microns in a drying box for 12-48 hours at the drying temperature of 100 ℃, and then weighing the silicon carbide with the average grain size of 50nm and the average grain size of 10 microns respectively for batching, wherein the mass fraction of the nano SiC is 0.1-50 wt%;
step two: mixing:
mixing materials by adopting a planetary ball mill, wherein the revolution speed is 200-400 r/min, the ball milling time is 1-3 hours, standing and cooling for 10 minutes after the ball milling is finished, taking out the mixed powder, and drying and storing;
step three: manufacturing a wire:
and (3) preparing the mixed powder into a cored wire with the diameter of 5mm by using a cored wire machine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710531600.4A CN107267704B (en) | 2017-07-03 | 2017-07-03 | Inoculant containing nano silicon carbide for nodular cast iron and vermicular cast iron and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710531600.4A CN107267704B (en) | 2017-07-03 | 2017-07-03 | Inoculant containing nano silicon carbide for nodular cast iron and vermicular cast iron and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107267704A CN107267704A (en) | 2017-10-20 |
| CN107267704B true CN107267704B (en) | 2023-03-24 |
Family
ID=60070846
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710531600.4A Active CN107267704B (en) | 2017-07-03 | 2017-07-03 | Inoculant containing nano silicon carbide for nodular cast iron and vermicular cast iron and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107267704B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108103260A (en) * | 2017-12-28 | 2018-06-01 | 合肥开尔纳米能源科技股份有限公司 | Core-spun yarn and preparation method thereof is bred in modification |
| CN108220523A (en) * | 2017-12-28 | 2018-06-29 | 合肥开尔纳米能源科技股份有限公司 | Modified inovulant and preparation method thereof |
| CN108148940A (en) * | 2017-12-28 | 2018-06-12 | 合肥开尔纳米能源科技股份有限公司 | Modified nodularization core-spun yarn and preparation method thereof |
| CN108165696A (en) * | 2017-12-28 | 2018-06-15 | 合肥开尔纳米能源科技股份有限公司 | Modified nodulizer and preparation method thereof |
| CN108620560B (en) * | 2018-05-11 | 2020-06-05 | 铜陵市大成轧辊有限责任公司 | Processing method for strengthening wear resistance of cast iron roller by adding particles |
| CN110193592B (en) * | 2019-06-24 | 2021-08-31 | 阜阳佳派生产力促进中心有限公司 | Method for improving corrosion resistance of differential case |
| CN112063791A (en) * | 2020-09-15 | 2020-12-11 | 禹州市恒利来新材料有限公司 | Nano silicon carbide and lanthanum rare earth composite inoculant and preparation method thereof |
| CN114318118B (en) * | 2021-08-30 | 2022-10-14 | 西安工业大学 | Silicon carbide reinforced synthetic vermicular graphite cast iron material and preparation method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000256722A (en) * | 1999-03-11 | 2000-09-19 | Toyota Motor Corp | Inoculant for spheroidal graphite cast iron and production thereof |
| CN105401049A (en) * | 2015-10-29 | 2016-03-16 | 宁波康发铸造有限公司 | Spheroidizing agent and preparation method and application thereof in spheroidal graphite cast iron smelting |
| CN106755702A (en) * | 2017-02-07 | 2017-05-31 | 吉林大学 | A kind of titanium aluminum carbide intermediate alloy as gray cast iron inovulant application |
| CN108103260A (en) * | 2017-12-28 | 2018-06-01 | 合肥开尔纳米能源科技股份有限公司 | Core-spun yarn and preparation method thereof is bred in modification |
-
2017
- 2017-07-03 CN CN201710531600.4A patent/CN107267704B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000256722A (en) * | 1999-03-11 | 2000-09-19 | Toyota Motor Corp | Inoculant for spheroidal graphite cast iron and production thereof |
| CN105401049A (en) * | 2015-10-29 | 2016-03-16 | 宁波康发铸造有限公司 | Spheroidizing agent and preparation method and application thereof in spheroidal graphite cast iron smelting |
| CN106755702A (en) * | 2017-02-07 | 2017-05-31 | 吉林大学 | A kind of titanium aluminum carbide intermediate alloy as gray cast iron inovulant application |
| CN108103260A (en) * | 2017-12-28 | 2018-06-01 | 合肥开尔纳米能源科技股份有限公司 | Core-spun yarn and preparation method thereof is bred in modification |
Non-Patent Citations (5)
| Title |
|---|
| SiC 对灰铸铁组织和性能的影响;周旭，郝晓燕等;《2013 中国铸造活动周论文集》;第1-6页 * |
| Structures and properties of cast irons reinforced by trace addition of modified SiC nanopowders;Li JW、Chen ML等;《Chinese Journal of Chemical Physics》;第20卷(第6期);第625-631页 * |
| 复合纳米碳化硅包芯线球墨铸铁孕育及其效果分析;刘美多等;《铸造》;第67卷(第02期);167-170页 * |
| 纳米 SiC 包芯线对大型球铁铸件的孕育研究;吴强、侯乐干等;《哈尔滨工程大学学报》;第37卷(第9期);第1302-1306页 * |
| 铸铁中石墨的形核问题;郭亚飞，魏汝梅;《热加工工艺》(第05期);17-20页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107267704A (en) | 2017-10-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107267704B (en) | Inoculant containing nano silicon carbide for nodular cast iron and vermicular cast iron and preparation method thereof | |
| CN109759578B (en) | Aluminum-based composite powder for 3D printing assembled and modified by two types of ultrafine ceramic particles and preparation method and application thereof | |
| CN1317411C (en) | Nano granule reinforced high-tough cast magnesium alloy and its preparing and shaping process | |
| CN102296196B (en) | Cross-scale in-situ particle reinforced aluminum matrix composite material and preparation method thereof | |
| CN104878275A (en) | Production technology for ductile iron casting with high strength and high ductility | |
| CN104513926A (en) | Spheroidal graphite cast iron with high strength and high elongation rate and preparation method of spheroidal graphite cast iron | |
| WO2022148060A1 (en) | High-entropy cast iron and preparation method therefor | |
| CN109055831B (en) | Nano hypereutectic aluminum-silicon alloy composite modifier and preparation method and application thereof | |
| CN101368237B (en) | Process for producing silicon particle reinforced zinc based composite material | |
| CN108148940A (en) | Modified nodularization core-spun yarn and preparation method thereof | |
| CN106636823B (en) | A kind of preparation method of novel magnesium alloy composite material | |
| CN108103260A (en) | Core-spun yarn and preparation method thereof is bred in modification | |
| CN101705405B (en) | Magnesium base spherical quasicrystal master alloy and preparation method thereof | |
| CN109321794A (en) | Al2Ca particle and carbon nano tube hybrid enhance ultralight Mg Li composites and preparation method | |
| CN104946961A (en) | Rear-earth inoculant, preparation method thereof and application thereof to grey cast iron | |
| JP4121733B2 (en) | Method for producing graphite-containing aluminum alloy and sliding member | |
| CN108672702A (en) | Damper knuckle support | |
| CN101705407B (en) | Magnesium base spherical quasicrystal master alloy and preparation method thereof | |
| CN108330308A (en) | A kind of Al-Ti-C-La composite crystal grain fining agents, alloy and preparation method thereof | |
| CN105385916A (en) | Nanometer chromium carbide-modified Mg-Al-Mn system magnesium alloy material for casting automobile parts and manufacturing method of nanometer chromium carbide-modified Mg-Al-Mn system magnesium alloy material | |
| CN105986204A (en) | Carbon-nanofiber-modified Mg-Al-Zn magnesium alloy material for casting automobile parts and preparation method of material | |
| CN105331865A (en) | Mg-Al-Zn system magnesium alloy material modified by nano-diamonds and used for casting automobile parts and manufacturing method of Mg-Al-Zn system magnesium alloy | |
| CN109825662A (en) | A kind of big specification Austria iron body spheroidal graphite cast-iron technique | |
| CN116716526B (en) | Nanoparticle refined magnesium-gadolinium intermediate alloy and preparation method thereof | |
| CN101705406B (en) | Magnesium-based spherical quasicrystal master alloy and preparation method thereof |
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 | ||
| CB03 | Change of inventor or designer information |
Inventor after: Wu Yubin Inventor after: Wu Ruizhi Inventor after: Wu Qiang Inventor after: Hou Legan Inventor before: Wu Ruizhi Inventor before: Wu Qiang Inventor before: Hou Legan |
|
| CB03 | Change of inventor or designer information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |