CN113695786A - Component of flux-cored wire for weathering resistant steel and preparation method thereof - Google Patents
Component of flux-cored wire for weathering resistant steel and preparation method thereof Download PDFInfo
- Publication number
- CN113695786A CN113695786A CN202111251053.7A CN202111251053A CN113695786A CN 113695786 A CN113695786 A CN 113695786A CN 202111251053 A CN202111251053 A CN 202111251053A CN 113695786 A CN113695786 A CN 113695786A
- Authority
- CN
- China
- Prior art keywords
- powder
- flux
- percent
- medicinal
- cored wire
- 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.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/32—Selection of soldering or welding materials proper with the principal constituent melting at more than 1550 degrees C
- B23K35/325—Ti as the principal constituent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/40—Making wire or rods for soldering or welding
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Nonmetallic Welding Materials (AREA)
Abstract
The invention relates to a flux-cored wire for weathering steel, which is characterized by comprising the following components in parts by weight: the powder comprises a low-carbon steel strip and powder, wherein the powder comprises: silicon-manganese alloy, electrolytic manganese, magnesia, nickel powder, copper powder, ferroboron, alumina, high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride. A preparation method of a flux-cored wire for weathering steel comprises the following steps: low-temperature drying is carried out on silicomanganese alloy, electrolytic manganese, nickel powder, copper powder, ferroboron and aluminum oxide in the components of the welding wire powder, the low-temperature drying temperature is 150-200 ℃, and the drying time is 1-2 hours; high-temperature drying is carried out on high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride in the components of the welding wire powder, the high-temperature drying temperature is 500-600 ℃, and the drying time is 6-8 hours; only the magnesia in the medicinal powder is not dried. Mixing all the medicinal powders uniformly, wrapping with steel belt with a medicinal powder filling ratio of 12-16%, and drawing for multiple times to obtain the final product.
Description
Technical Field
The invention relates to the technical field of welding materials, in particular to a component of a flux-cored welding wire for weathering resistant steel and a preparation method thereof.
Background
The steel structure bridge has high strength and strong bearing capacity, is convenient for industrial processing, and can use the lightest material to bear the final load. The periodic cost of the bridge is reduced, the bridge construction trend is achieved, the durability of the common bridge is outstanding, the bridge is usually protected by a coating, multiple times of protective coating are needed in the whole service life period of the bridge, and the cost is high. The weathering steel has the characteristics of a common steel structure, and can also exert the corrosion resistance without coating. The popularization of weathering steel on bridges is a great trend at present, but welding materials required when the steel is welded must be matched with the steel.
The weathering steel contains a small amount of Cu, P or Cr, Ni and other elements (the general contents of P is about 0.1 percent and Cr is about 0.4 percent), so that the atmospheric corrosion resistance of the weathering steel is improved by more than 1/3 compared with that of common carbon steel (such as Q215, Q235 and the like). Weathering resistant steels such as: 08MnP, 15MnVCu, 16MnCu, 10NiCuP, 10MnPNbRe steel and the like, and can be used for container, bridge, locomotive, oil derrick and port engineering. The system for depositing metal alloy by using weathering steel welding wire can be generally divided into: Cu-Cr series, Cu-Cr-Ni series and Cu-Ni series, and the tensile strength is 490MPa and 590 MPa.
The western technologists Legault and leckie predict the corrosion of low alloy steels after 15.5 years exposure to the atmosphere based on the chemical composition of the steel and are based on a large amount of data. For application in industrial environments, the formula is modified so that an atmospheric corrosion resistance index can be calculated, the greater the index, the better the corrosion resistance of the steel or weld. The index I is as follows:
I=26.01(%Cu)+3.88(%Ni)+1.20(%Cr)+1.49(%Si)+17.28(%P)-7.29(%Cu)(%Ni)-9.10(%Ni)(%P)-33.39(%Cu)2
at present, flux-cored wires for weathering steel used in a plurality of major industries such as major engineering, shipbuilding, nuclear power, construction, machinery, petrochemical industry, pressure vessels, vehicles and the like mainly depend on import, and the main reason is that the number of manufacturers for producing the welding materials is small in China, the quality is uneven, and the market prospect of the flux-cored wires for weathering steel matched with the flux-cored wires for weathering steel is optimistic along with the large-scale use of the weathering steel.
Disclosure of Invention
In order to solve the problems, the invention aims to provide a component of a flux-cored wire for weathering steel, which can be matched with the characteristics of the weathering steel, and a preparation method thereof.
In order to achieve the purpose, the invention adopts the technical scheme that: the components of the flux-cored wire for weathering steel are characterized in that: the powder comprises a low-carbon steel strip and powder, wherein the powder comprises: silicon-manganese alloy, electrolytic manganese, magnesia, nickel powder, copper powder, ferroboron, alumina, high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride. The mass percentage of each component in the medicinal powder to the total medicinal powder is as follows: 41-46% of high-grade 97-degree rutile, 10.5-13% of silicon-manganese alloy, 3.5-5.0% of potassium titanate, 5.5-10.0% of electrolytic manganese, 1.1-5.0% of quartz sand, 5.0-6.5% of magnesia, 1.5-4.0% of sodium fluoride, 2.0-6.0% of ferroboron, 0.5-1.5% of alumina, 2.0-4.5% of nickel powder, copper powder: 5.0 to 7.0 percent.
A preparation method of a flux-cored wire for weathering steel comprises the following steps:
low-temperature drying is carried out on silicomanganese alloy, electrolytic manganese, nickel powder, copper powder, ferroboron and aluminum oxide in the components of the welding wire powder, the low-temperature drying temperature is 150-200 ℃, and the drying time is 1-2 hours; high-temperature drying is carried out on high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride in the components of the welding wire powder, the high-temperature drying temperature is 500-600 ℃, and the drying time is 6-8 hours; only magnesia is not dried in the medicinal powder;
mixing all the medicinal powders uniformly, wrapping with steel belt with a medicinal powder filling ratio of 12-16%, and drawing for multiple times to obtain the final product.
The preparation method of the flux-cored wire for weathering steel further comprises the following steps: and during drawing, 5 times of rough drawing and 10 times of fine drawing are sequentially carried out.
Compared with the prior art, the invention has the following beneficial effects: the deposited metal alloy system of the flux-cored wire for the weathering steel is Cu-Cr-Ni system, and the strength grade is 490 MPa. The formula of the flux-cored welding wire powder for the weathering steel is optimized, so that molten drops are in transition of fine particles in the welding process, splashing is small, the arc stability is good, the welding seam forming is excellent, smoke is small during welding, slag is easy to remove, the product performance meets the welding application requirements for the weathering steel, and the atmospheric corrosion resistance coefficient I of deposited metal is more than or equal to 6.0.
Detailed Description
The components of the flux-cored wire for weathering steel and the preparation method thereof according to the present invention are further described in detail by the following embodiments.
The components of the flux-cored wire for the weathering steel comprise a low-carbon steel strip and powder, wherein the powder comprises: silicon-manganese alloy, electrolytic manganese, magnesia, nickel powder, copper powder, ferroboron, alumina, high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride. The mass percentage of each component in the medicinal powder to the total medicinal powder is as follows: 41-46% of high-grade 97-degree rutile, 10.5-13% of silicon-manganese alloy, 3.5-5.0% of potassium titanate, 5.5-10.0% of electrolytic manganese, 1.1-5.0% of quartz sand, 5.0-6.5% of magnesia, 1.5-4.0% of sodium fluoride, 2.0-6.0% of ferroboron, 0.5-1.5% of alumina, 2.0-4.5% of nickel powder, copper powder: 5.0 to 7.0 percent.
Example 1
The components of the flux-cored wire for the weathering steel comprise a low-carbon steel strip and powder, wherein the powder comprises: silicon-manganese alloy, electrolytic manganese, magnesia, nickel powder, copper powder, ferroboron, alumina, high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride. The mass percentage of each component in the medicinal powder to the total medicinal powder is as follows: 46 percent of high-grade 97-degree rutile, 13 percent of silicon-manganese alloy, 5.0 percent of potassium titanate, 10.0 percent of electrolytic manganese, 4 percent of quartz sand, 6.0 percent of magnesia, 2 percent of sodium fluoride, 2.0 percent of ferroboron, 1 percent of alumina, 4 percent of nickel powder, and copper powder: 7.0 percent.
Through welding test, the tensile strength of deposited metal is as follows: 546MPa, lower yield strength: 435MPa, elongation: 26%, -40 degree impact average: 136J, deposited metal main chemical composition:
0.42 percent of Cu, 0.84 percent of Ni, 0.19 percent of Cr, 0.36 percent of Si and 0.01 percent of P. The atmospheric corrosion resistance coefficient I =6.58, and meets the design requirement.
Example 2
The components of the flux-cored wire for the weathering steel comprise a low-carbon steel strip and powder, wherein the powder comprises: silicon-manganese alloy, electrolytic manganese, magnesia, nickel powder, copper powder, ferroboron, alumina, high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride. The mass percentage of each component in the medicinal powder to the total medicinal powder is as follows: 41 percent of high-grade 97-degree rutile, 12.5 percent of silicon-manganese alloy, 5.0 percent of potassium titanate, 10.0 percent of electrolytic manganese, 5.0 percent of quartz sand, 6.5 percent of magnesia, 4.0 percent of sodium fluoride, 5.0 percent of ferroboron, 1.5 percent of alumina, 4.5 percent of nickel powder, and copper powder: 5.0 percent.
Through welding test, the tensile strength of deposited metal is as follows: 538MPa, lower yield strength: 433MPa, elongation: 28%, -40 degree impact average: 149J, deposited metal main chemical composition:
0.32 percent of Cu, 0.89 percent of Ni, 0.18 percent of Cr, 0.40 percent of Si and 0.023 percent of P. The atmospheric corrosion resistance coefficient I =7.30, and meets the design requirement.
Example 3
The components of the flux-cored wire for the weathering steel comprise a low-carbon steel strip and powder, wherein the powder comprises: silicon-manganese alloy, electrolytic manganese, magnesia, nickel powder, copper powder, ferroboron, alumina, high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride. The mass percentage of each component in the medicinal powder to the total medicinal powder is as follows: 43% of high-grade 97-degree rutile, 13% of silicon-manganese alloy, 4% of potassium titanate, 9% of electrolytic manganese, 4% of quartz sand, 6% of magnesia, 4% of sodium fluoride, 6.0% of ferroboron, 1% of alumina, 4% of nickel powder, 4% of copper powder: 6 percent.
Through welding test, the tensile strength of deposited metal is as follows: 549MPa, lower yield strength: 436MPa, elongation: 28%, -40 degree impact average: 138J, deposited metal main chemical composition:
0.38 percent of Cu, 0.85 percent of Ni, 0.18 percent of Cr, 0.37 percent of Si and 0.028 percent of P. The atmospheric corrosion resistance coefficient I =7.04, and the design requirement is met.
A preparation method of a flux-cored wire for weathering steel comprises the following steps:
low-temperature drying is carried out on silicomanganese alloy, electrolytic manganese, nickel powder, copper powder, ferroboron and aluminum oxide in the components of the welding wire powder, the low-temperature drying temperature is 150-200 ℃, and the drying time is 1-2 hours; high-temperature drying is carried out on high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride in the components of the welding wire powder, the high-temperature drying temperature is 500-600 ℃, and the drying time is 6-8 hours; only magnesia is not dried in the medicinal powder;
mixing all the medicinal powders uniformly, wrapping with steel belt with a medicinal powder filling ratio of 12-16%, and drawing for multiple times sequentially for 5 times of rough drawing and 10 times of fine drawing to obtain the final product.
Through research on common welding materials and weathering steel, a small amount of alloy elements P, Cr, Mo, Ni and Cu in chemical compositions play a determining role in corrosion resistance. The weather-resistant steel welding material is matched with weather-resistant steel in the aspects of strength, low-temperature toughness, weather resistance, welding operation performance, welding seam crack sensitivity and the like. Slagging agent MgO-SiO in flux-cored wire for weathering resistant steel2-TiO2-Al2O3Deoxidizer Si-Mn-Mg, nitrogen fixing agent Al-Mg-Ti-Zr and alloying agent Si-Mn-Ni-Ti-B, corrosion-resistant agent Cu and arc stabilizer Na-Mg-K-TiO2And other substances for improving the welding process performance and the metal performance and the atmospheric corrosion resistance of the welding seam, wherein the substances comprise nickel, molybdenum, zirconium, titanium, boron and other trace elements which influence the welding seam structure and the mechanical performance.
Tests show that the chemical and mechanical properties of the flux-cored wire for the weathering steel meet the standards of the flux-cored wire for the weathering steel, and the specific indexes are as follows:
the atmospheric corrosion resistance coefficient I is more than or equal to 6.0
The deposited metal comprises the following main chemical components of less than or equal to 0.12 percent of C, Mn: 0.5-1.30, Si: 0.35-0.80, P is less than or equal to 0.030, S is less than or equal to 0.030, Ni: 0.4-0.9, Cr: 0.15-0.7, Cu: 0.30-0.75, V is less than or equal to 0.05
Tensile strength: 490-620MPa
The lower yield strength is more than or equal to 400MPa
The elongation is more than or equal to 20 percent
Impact value of-40 ℃ is more than or equal to 27J
The above-mentioned embodiments are merely illustrative of the principles and effects of the present invention, and some embodiments may be used, not restrictive; it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications belong to the protection scope of the present invention.
Claims (3)
1. The components of the flux-cored wire for weathering steel are characterized in that: the powder comprises a low-carbon steel strip and powder, wherein the powder comprises: silicomanganese alloy, electrolytic manganese, magnesia, nickel powder, copper powder, ferroboron, alumina, high grade 97 degree rutile, potassium titanate, quartz sand and sodium fluoride; the mass percentage of each component in the medicinal powder to the total medicinal powder is as follows: 41-46% of high-grade 97-degree rutile, 10.5-13% of silicon-manganese alloy, 3.5-5.0% of titanium potassium, 5.5-10.0% of electrolytic manganese, 1.1-5.0% of quartz sand, 5.0-6.5% of magnesia, 1.5-4.0% of sodium fluoride, 2.0-6.0% of ferroboron, 0.5-1.5% of alumina, 2.0-4.5% of nickel powder, copper powder: 5.0 to 7.0 percent.
2. A preparation method of a flux-cored wire for weathering steel is characterized by comprising the following steps: the method comprises the following steps:
low-temperature drying is carried out on silicomanganese alloy, electrolytic manganese, nickel powder, copper powder, ferroboron and aluminum oxide in the components of the welding wire powder, the low-temperature drying temperature is 150-200 ℃, and the drying time is 1-2 hours; high-temperature drying is carried out on high-grade 97-degree rutile, potassium titanate, quartz sand and sodium fluoride in the components of the welding wire powder, the high-temperature drying temperature is 500-600 ℃, and the drying time is 6-8 hours; only magnesia is not dried in the medicinal powder;
mixing all the medicinal powders uniformly, wrapping with steel belt with a medicinal powder filling ratio of 12-16%, and drawing for multiple times to obtain the final product.
3. The method for preparing the flux-cored wire for weathering steel according to claim 2, wherein: and during drawing, 5 times of rough drawing and 10 times of fine drawing are sequentially carried out.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111251053.7A CN113695786A (en) | 2021-10-27 | 2021-10-27 | Component of flux-cored wire for weathering resistant steel and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111251053.7A CN113695786A (en) | 2021-10-27 | 2021-10-27 | Component of flux-cored wire for weathering resistant steel and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113695786A true CN113695786A (en) | 2021-11-26 |
Family
ID=78647050
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111251053.7A Withdrawn CN113695786A (en) | 2021-10-27 | 2021-10-27 | Component of flux-cored wire for weathering resistant steel and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113695786A (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102310301A (en) * | 2011-08-25 | 2012-01-11 | 张家港市亨昌焊材有限公司 | Flux-cored wire |
| JP2013151001A (en) * | 2012-01-25 | 2013-08-08 | Nippon Steel & Sumikin Welding Co Ltd | Flux-cored wire for gas-shielded arc welding for weather-resistant steel |
| JP2018047487A (en) * | 2016-09-21 | 2018-03-29 | 新日鐵住金株式会社 | Flux-cored wire for gas shielded arc welding of corrosion-resistant steel |
| CN108356447A (en) * | 2018-03-16 | 2018-08-03 | 西安理工大学 | G520 stainless steels and 25Cr2Ni4MoV steel alloys welding Self-protecting flux-cored wire and preparation method thereof |
| CN110640352A (en) * | 2019-11-13 | 2020-01-03 | 四川大西洋焊接材料股份有限公司 | Flux-cored wire for Q500qENH coating-free bridge steel and preparation method thereof |
| CN111215788A (en) * | 2019-12-04 | 2020-06-02 | 天津市永昌焊丝有限公司 | Titanium type flux-cored wire for 62 kg-grade weathering steel |
| CN112222682A (en) * | 2020-09-07 | 2021-01-15 | 南京工程学院 | High-fluorine-alkali type powder, preparation method and self-shielded flux-cored wire |
| CN112404797A (en) * | 2020-12-06 | 2021-02-26 | 中铁宝桥集团有限公司 | Novel welding wire and method for welding 321+ Q370qENH composite steel transition layer |
| CN112548398A (en) * | 2020-12-08 | 2021-03-26 | 上海焊接器材有限公司 | Ultralow-hydrogen flux-cored wire for 62 Kg-grade weathering steel and manufacturing method thereof |
-
2021
- 2021-10-27 CN CN202111251053.7A patent/CN113695786A/en not_active Withdrawn
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102310301A (en) * | 2011-08-25 | 2012-01-11 | 张家港市亨昌焊材有限公司 | Flux-cored wire |
| JP2013151001A (en) * | 2012-01-25 | 2013-08-08 | Nippon Steel & Sumikin Welding Co Ltd | Flux-cored wire for gas-shielded arc welding for weather-resistant steel |
| JP2018047487A (en) * | 2016-09-21 | 2018-03-29 | 新日鐵住金株式会社 | Flux-cored wire for gas shielded arc welding of corrosion-resistant steel |
| CN108356447A (en) * | 2018-03-16 | 2018-08-03 | 西安理工大学 | G520 stainless steels and 25Cr2Ni4MoV steel alloys welding Self-protecting flux-cored wire and preparation method thereof |
| CN110640352A (en) * | 2019-11-13 | 2020-01-03 | 四川大西洋焊接材料股份有限公司 | Flux-cored wire for Q500qENH coating-free bridge steel and preparation method thereof |
| CN111215788A (en) * | 2019-12-04 | 2020-06-02 | 天津市永昌焊丝有限公司 | Titanium type flux-cored wire for 62 kg-grade weathering steel |
| CN112222682A (en) * | 2020-09-07 | 2021-01-15 | 南京工程学院 | High-fluorine-alkali type powder, preparation method and self-shielded flux-cored wire |
| CN112404797A (en) * | 2020-12-06 | 2021-02-26 | 中铁宝桥集团有限公司 | Novel welding wire and method for welding 321+ Q370qENH composite steel transition layer |
| CN112548398A (en) * | 2020-12-08 | 2021-03-26 | 上海焊接器材有限公司 | Ultralow-hydrogen flux-cored wire for 62 Kg-grade weathering steel and manufacturing method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 徐峰等: "《焊接工艺简明手册 第2版》", 30 September 2014 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111266761B (en) | Low-nickel nitrogen-containing austenitic stainless steel flux-cored wire and preparation method thereof | |
| CN103028865B (en) | High-corrosion-resistance gas protection welding wire | |
| CN101905392B (en) | High-toughness low-alloy solid welding wire | |
| CN101987403B (en) | 900MPa-level high-performance gas shielded welding wire | |
| CN112122821B (en) | Wear-resistant and corrosion-resistant flux-cored wire for TIG-P surfacing of hydraulic support component | |
| CN107283084B (en) | A kind of marine atmosphere corrosion-resisting steel submerged arc flux-cored wire | |
| CN107252996B (en) | Titanium type gas shielded flux-cored wire for marine atmospheric corrosion resistant steel | |
| CN110293332B (en) | High-strength weather-proof and fire-resistant steel welding alkaline flux-cored wire | |
| CN108907498A (en) | A kind of high tenacity corrosion resistant submerged arc metal powder core solder wire | |
| CN110802342B (en) | High-strength weathering steel Q550NQR1 and Q550qNH matched welding rod | |
| CN105643139A (en) | Solid welding wire for high-strength weather-resistant steel | |
| CN105345311B (en) | The high anti-corrosion welding rod of rail freight | |
| CN110284060A (en) | A kind of Coal Transportation truck body high-strength anticorrosion steel and its manufacturing method | |
| CN105397332B (en) | The high anti-corrosion flux-cored wire of rail freight | |
| CN101041213A (en) | Metal powder core filler metal for welding of high-tensile steel | |
| CN113695786A (en) | Component of flux-cored wire for weathering resistant steel and preparation method thereof | |
| CN100398250C (en) | High-strength weather-resistant welding rod | |
| CN103600178A (en) | High-strength solid wire made of weathering resistant steel through gas shielded welding | |
| CN102019518B (en) | Two phase stainless steel welding rod | |
| CN111299899A (en) | Marine atmosphere corrosion resistant steel matched gas shielded welding wire rod, welding wire and application | |
| CN111299900A (en) | Marine atmosphere corrosion resistant steel matched gas shielded welding wire rod, welding wire and application | |
| JP2023526333A (en) | Wire rod for gas-shielded welding wire and gas-shielded welding wire | |
| CN112935626A (en) | Metal powder cored flux-cored wire for welding fire-resistant weathering steel | |
| CN115008066B (en) | Self-protection flux-cored wire for weathering steel | |
| CN112139699B (en) | Welding wire with yield strength of 550MPa grade for enamel steel |
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 | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20211126 |