CN109804092A - Flux-cored wire cold-rolled steel sheet and its manufacturing method - Google Patents
Flux-cored wire cold-rolled steel sheet and its manufacturing method Download PDFInfo
- Publication number
- CN109804092A CN109804092A CN201780062649.8A CN201780062649A CN109804092A CN 109804092 A CN109804092 A CN 109804092A CN 201780062649 A CN201780062649 A CN 201780062649A CN 109804092 A CN109804092 A CN 109804092A
- Authority
- CN
- China
- Prior art keywords
- rolled steel
- steel sheet
- cold
- flux
- 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.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
-
- 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
- B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
- B23K35/0255—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in welding
- B23K35/0261—Rods, electrodes, wires
- B23K35/0266—Rods, electrodes, wires flux-cored
-
- 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
- B23K35/406—Filled tubular wire or rods
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0236—Cold rolling
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
-
- 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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- 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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- 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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- 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
- C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Nonmetallic Welding Materials (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
One aspect of the present invention is related to a kind of flux-cored wire cold-rolled steel sheet, the flux-cored wire cold-rolled steel sheet, in terms of weight %, include: C:0.01~0.15%, Mn:0.1~0.5%, Si:0.05% or less (except 0%), P:0.0005~0.01%, S:0.008% or less (except 0%), Al:0.005~0.06%, N:0.0005~0.003%, the Fe and inevitable impurity of Ni:0.5~2.0% and surplus, in terms of area fraction, microstructure includes 93~98% ferrite, and total includes 2~7% acicular bainite and cementite.
Description
Technical field
The present invention relates to a kind of flux-cored wire cold-rolled steel sheet and its manufacturing methods.
Background technique
For welding rod material, positive complex bacteria tearen simultaneously applies steel plate and solder flux (Flux) material, to meet multiple use.Make
For typical use, the extremely low temperature of the welding assembly, excellent tenacity at extremely low temperatures that develop the excellent high Mn steel of wearability is used
A variety of welding assemblies for special purposes such as the excellent shockproof steel welding assembly of welding assembly, shockproof properties.Therefore, at present
Also develop the welding rod material for meeting these special welding steels.
The productivity highest and welding method for being easy a variety of positions of welding has flux-cored wire weldering in general welding method
Connect (Flux Cored Welding, FCW) method.The welding material used in the welding method is flux-cored wire (Flux
Cored Wire), the strip (Strip) after the common cold-rolled steel sheet of drawing is processed into U-shaped, is added in the U-shaped pipe of processing
About 5~50% degree of weight ratio are used for ensuring the operational flux constituent of welding and in order to ensure using suitable for welding rod
The characteristic on way and the alloying elements such as manganese (Mn), nickel (Ni) for being mixed according to purpose with powder morphology, then manufacture circular welding rod
Use material.
At this point, ensuring welding rod material by changing type and additive amount with the in-core alloying component of powder morphology addition
Multifrequency nature needed for material.Therefore the welding assembly that low-temperature flexibility is required to produce such as extremely low temperature with welding assembly, needs
The element for being used to improve low-temperature flexibility is placed individually into wire core as the alloying element being added in solder flux.
On the other hand, as around welding wire cold rolling steel for manufacturing the core of flux-cored wire, generally using not adding
Add the ordinary carbon steel of a large amount of alloying element, and uses stainless steel in some specific uses.
The elongation percentage of steel for welding wire material based on ordinary carbon steel is excellent, so that the tearing that steel will not occur in drawing is existing
As, and since processing curing degree is low, even if from other heat treatment is needed not move through during the manufacture for being molded into final welding wire
Technique also can be manufactured continuously, therefore be widely used in many on the way.But carbon steel welding steel as described above are
Low-alloy steel, thus need to add the solder flux and in-core alloying element for inside filler wire in order to ensure the characteristic of welding rod,
But in order to ensure welding operability, the additive amount of substantially solder flux needs to rationalize, therefore improves in-core alloying element and exist
Limitation.That is, it needs to add a large amount of oxidant (Ti, Mn, Zr, Al etc.), slag forming agent in the centre of welding wire steel
(TiO2、SiO2、Al2O3、ZrO2, MnO etc.), arc stabilizer (K, Na etc.) and alloying component (Si, Mn, Ni, Zr, Cr etc.) etc. all,
And the filling flux in welding wire steel, and about 30~60% volume of the limit of mentioned component is filled, although according to the powder of filling
End and have differences, but be about 15~25% degree with the weight ratio meter limit.In this case, for ensuring the conjunction of characteristic
When the content of gold element increases, since flux constituent etc. is restricted, and it is difficult to ensure welding characteristic.In addition, with the conjunction
Gold element is added with powder morphology, weld part can be caused to be segregated welding the core component melted when operation, therefore also become welding
Bad reason.
For using the steel for welding wire material of stainless steel, the alloying elements such as nickel (Ni) or chromium (Cr) present in low-carbon composition of steel
Amount be substantially greater than ordinary carbon steel, therefore, it is possible to reduce the additive amount of the core alloying element added together with solder flux, but by
It is substantially high alloy material in it, raw sheet material price is high, therefore be only applicable to specific use etc..Moreover, for this
A little stainless steel welded raw sheets, it is high due to processing a possibility that solidifying and breaking when processing welding wire, thus in manufacturing process
Period also needs additionally to execute annealing, therefore can improve manufacturing cost.
Currently, for needing processability, especially for the extremely low temperature of drawing processability and low-temperature flexibility steel for welding wire material,
In order to ensure using low-temperature flexibility when being packed into solder flux after ordinary carbon steel tubing, the member of high price is prepared in the form of high purity powdered form
Element, and put into together with other flux constituents, to improve low-temperature flexibility, but in this case, due to added alloy
Powder is high-purity and price is high, and input amount is more, for ensuring that the adding conditional of flux constituent of welding stability can be by
To limitation.In addition, the alloying element for the high price added at this time causes segregation phenomena in solder flux, therefore it can also make welding operability
It is deteriorated.
For example, in patent document 1 as manufacture flux-cored wire steel plate method, disclose containing Mn:1.4~
2.4%, Cr, Mo, Ti etc. are added in the steel of Si:0.2~0.4%, Ni:2.8~6.4% to manufacture impact flexibility and strength characteristics
The method of excellent welding rod steel.But add a large amount of high-priced alloying element in patent document 1 and lead to cost increase, separately
Outside, high intensity can be ensured by addition alloying element, but is difficult to ensure drawing processability due to poor ductility.
Promote the deoxidation of molten metal in addition, being disclosed in patent document 2 by adding Ti, Mg etc. in solder flux raw material
Reaction, to reduce the technology of welding defect.But it in order to obtain the deoxidation effect of sufficient molten metal, needs in solder flux
The middle a large amount of alloying element of addition, however when adding a large amount of alloying element as described above in solder flux, there are when welding
Fine particle occurs and splashes the problem of welding operability such as splashing (spatter) phenomenon of surrounding reduces.
Therefore, it is necessary to develop a kind of weld part that can obtain the excellent in low temperature toughness under the low temperature environment of pole, and weld
The flux-cored wire cold-rolled steel sheet and its manufacturing method of operability and drawing excellent in workability.
Existing technical literature
(patent document 1) Korean Patent Laid the 2006-107910th
(patent document 2) Japanese Laid-Open Patent Publication 60-46896
Summary of the invention
(1) technical problems to be solved
According to an aspect of the present invention, its purpose is to provide the medicines of a kind of welding operability and drawing excellent in workability
Core welding wire cold-rolled steel sheet and its manufacturing method.
In addition, the technical problem to be solved in the present invention is not limited to above-mentioned content.The invention solves technology ask
Topic can understand that general technical staff of the technical field of the invention is understood that by the content of the whole instruction
The invention solves accessory problem.
(2) technical solution
One aspect of the present invention is related to a kind of flux-cored wire cold-rolled steel sheet of excellent in low temperature toughness, the medicine core weldering
Silk cold-rolled steel sheet includes in terms of weight %: (0% removes by C:0.01~0.15%, Mn:0.1~0.5%, Si:0.05% or less
Outside), P:0.0005~0.01%, S:0.008% or less (except 0%), Al:0.005~0.06%, N:0.0005~
0.003%, Ni:0.5~2.0% and the Fe and inevitable impurity of surplus, in terms of area fraction, microstructure include 93~
98% ferrite, and add up to acicular bainite and cementite comprising 2~7%.
In addition, another aspect of the present invention, is related to a kind of manufacturing method of flux-cored wire cold-rolled steel sheet, the method packet
Include following steps: by heating of plate blank to 1100~1300 DEG C, the slab includes in terms of weight %: C:0.01~0.15%,
Mn:0.1~0.5%, Si:0.05% or less (except 0%), P:0.0005~0.01%, S:0.008% or less (except 0%),
Al:0.005~0.06%, N:0.0005~0.003%, Ni:0.5~2.0% and surplus Fe and inevitable impurity；It is right
The slab of heating carries out hot rolling, until hot finishing temperature reaches 880~950 DEG C, to obtain hot rolled steel plate；550~700
Within the temperature range of DEG C, the hot rolled steel plate is wound；With 50~85% reduction ratio, the hot rolled steel plate of winding is carried out cold
It rolls, to obtain cold-rolled steel sheet；And continuous annealing is carried out to the cold-rolled steel sheet.
Also, whole features of the invention are not listed in the above technical solution.Various features and base of the invention
In this feature the advantages of and effect is referred to following specific embodiment to be more fully understood.
(3) beneficial effect
According to the present invention it is possible to provide welding operability and drawing excellent in workability flux-cored wire cold-rolled steel sheet and its
Manufacturing method.
Detailed description of the invention
Fig. 1 is the photo for shooting the microstructure of example 2.
Fig. 2 is the photo for shooting the microstructure of comparative example 6.
Preferred forms
In the following, being illustrated to the preferred embodiment of the present invention.But embodiments of the present invention can be changed to it
His various ways, the scope of the present invention will not be defined in embodiments described below.In addition, embodiments of the present invention be for
Further completely illustrate to person of an ordinary skill in the technical field the present invention and provides.
Flux-cored wire cold-rolled steel sheet
In the following, flux-cored wire according to an aspect of the present invention is described in detail with cold-rolled steel sheet.
Flux-cored wire cold-rolled steel sheet according to an aspect of the present invention includes in terms of weight %: C:0.01~
0.15%, Mn:0.1~0.5%, Si:0.05% or less (except 0%), P:0.0005~0.01%, S:0.008% or less
(except 0%), Al:0.005~0.06%, N:0.0005~0.003%, Ni:0.5~2.0% and surplus Fe and can not keep away
The impurity exempted from, in terms of area fraction, microstructure includes 93~98% ferrite, and adds up to the needle-shaped shellfish comprising 2~7%
Family name's body and cementite.
Firstly, composition of alloy of the invention is described in detail.Unless otherwise specified, following each element content
Unit indicates weight %.
C:0.01~0.15%
The element that carbon (C) is added typically to the intensity for improving steel, and be to have welding heat affected zone
Characteristic similar with base material and the element added.
When C content is less than 0.01%, the effect is insufficient.On the other hand, when C content is more than 0.15%, due to
High-intensitive or processing solidification, and the problems such as may break in drawing processing.In addition, can make welded-joint that low temperature occur
It is cracked or impact flexibility reduces, and need to be implemented repeatedly heat treatment due to high rigidity can just be processed into final products.Therefore,
C content is preferably 0.01~0.15%, and in order to improve the characteristic of welding heat affected zone, it can be more preferably 0.02~
0.13%.
Mn:0.1~0.5%
Manganese (Mn) is used as solution strengthening element, has the intensity for improving steel, reduces Ar3, to improve the work of hot-workability
With.But as the Mn of excessive addition, a large amount of manganese-sulfide (MnS) precipitate is formed, the ductility of steel may be hindered
And processability.
When Mn content is less than 0.1%, become the reason of causing red shortness, and be difficult to facilitate the stabilization of austenite
Change.On the other hand, when Mn content is more than 0.5%, ductility reduction, and due to adding a large amount of alloying element, so that at
Simultaneously center segregation occurs for this rising, and may cause broken string in drawing operation.Therefore Mn content is preferably 0.1~0.5%,
0.2~0.45% can be more preferably.
Si:0.05% or less (except 0%)
Silicon (Si) and oxygen etc. in conjunction with and steel plate surface formed oxide layer, thus become make surface characteristic be deteriorated and reduce
Corrosion proof reason, and promote the transformation of the hard phase in welding metal, and become the reason of reducing low-temperature flexibility, therefore will
The additive amount of Si is limited in 0.05% or less.It is highly preferred that Si content can be 0.04% hereinafter, can even more preferably be
0.02% or less.
P:0.0005~0.01%
Phosphorus (P) is to exist in steel with solid solution element and improve the intensity of steel and the member of hardness by causing solution strengthening
Element, and the rigidity in order to keep predetermined extent preferably add 0.0005% or more, but when P content is more than 0.01%,
Cause center segregation when casting, and reduce ductility, so as to make welding wire processability be deteriorated.Therefore P content is preferably
0.0005~0.01%, 0.001~0.009% can be more preferably.
S:0.008% or less (except 0%)
Sulphur (S) forms non-metallic inclusion in conjunction with the Mn in steel, and becomes red shortness (red shortness)
The reason of, it is therefore preferred to reduce S content as far as possible.In addition, the base metal tenacity of steel plate, therefore S can be reduced when S content is high
Content is preferably 0.008% hereinafter, 0.007% or less can be more preferably.
Al:0.005~0.06%
Aluminium (Al) be in aluminum killed steel in order to prevent the material as caused by deoxidier and timeliness be deteriorated and add element,
It and is the element it is advantageously ensured that ductility, this effect is more significant compared at extremely low temperatures.
When Al content is less than 0.005%, the effect is insufficient.On the other hand, when Al content is more than 0.06%, oxygen
Change aluminium (Al2O3) etc. surface inclusions increase severely, so that the surface characteristic of hot-finished material be made to deteriorate, reduction processability, and welding
Local ferrite is formed in heat affected zone crystal boundary, to mechanical property can be made to reduce, and weld seam (bead) shape after welding
Shape possible deviation.Therefore, Al content is preferably 0.005~0.06%.It is highly preferred that Al content can be 0.01~0.05%,
It can even more preferably be 0.01~0.04%.
N:0.0005~0.003%
Nitrogen (N) is to be present in inside steel with solid solution condition and strengthen effective element to material, in order to ensure target is rigid,
Need to add 0.0005% or more N.On the other hand, when N content is more than 0.003%, timeliness is sharply deteriorated, and in steel
Manufacturing step in increase the burden based on denitrogenation, thus steel operability processed be deteriorated.Therefore, N content be preferably 0.0005~
0.003%.It is highly preferred that N content can be 0.001~0.0027%.
Ni:0.5~2.0%
Nickel (Ni) be improve ductility to effectively improve drawing processability, and formed at extremely low temperatures stable tissue with
Improve the necessary element of low-temperature flexibility.When Ni is added as the addition of the ingredient of solder flux not as the ingredient of steel plate, by
In needing to manufacture Ni with the powder morphology of high-purity, therefore adds Ni and be advantageous in terms of cost as the ingredient of steel plate.
In addition, point rate added due to can be used as solder flux in welding rod is restricted, ingredient of the Ni as steel plate is added, thus
The amount for influencing other solder flux elements of weldability can be increased, therefore weldability can be improved etc..
When Ni content is less than 0.5%, the effect is insufficient.On the other hand, when Ni content is more than 2.0%, due to
Intensity rises, and drawing processability possible deviation, and may cause surface defect, since Ni is high valence elements, manufacture
Cost increase.Therefore, Ni content is preferably 0.5~2.0%.It is highly preferred that Ni content can be 0.6~1.8%.
Remaining ingredient of the invention is iron (Fe).It, may be from raw material or ambient enviroment but in traditional manufacturing process
In be inevitably mixed into unexpected impurity, therefore cannot exclude the impurity.The impurity is for conventional fabrication process
Technical staff for be well known, therefore its all the elements is not illustrated in this specification.
At this point, not only meet the range of each element content, the W defined by following relational expressions 1FCCan for 0.5~
4.5.The unit of each element content is weight % in following relational expressions 1.
Relational expression 1:WFC=(25*C+0.4*Mn+26*Al) * Ni
The relational expression 1 allows for the correlativity for each element for influencing welding operability and drawing processability and designs
's.
Work as WFCWhen less than 0.5, the transformation amount from room temperature tissue to hard phase is few, thus be advantageous in terms of processability,
But in order to ensure low-temperature flexibility, the alloy amount added with the alloying element as solder flux increases, and welds operability and becomes
Difference.Therefore, WFCLower limit be preferably 0.5, preferred lower limit can be 0.505.
On the other hand, work as WFCWhen more than 4.5, the hard score for changing tissue increases, to can occur in tubing and drawing
The problem of welding assembly is broken, and with the alloying element for adding a large amount of high price, manufacturing cost rises.Therefore, WFCIt is upper
Limit preferably 4.5, the preferred upper limit can be 4.0, and the upper limit even more preferably can be 3.5.
In terms of area fraction, the microstructure of cold-rolled steel sheet according to the present invention includes 93~98% ferrite, and
Total includes 2~7% acicular bainite and cementite.
When ferrite fraction is less than 93%, material solidification, thus the reason of becoming fracture when tubing and drawing are processed,
When ferrite fraction is more than 98%, rigidity is reduced due to softening with material, the thickness of flux-cored wire rises.Cause
This, ferritic score is preferably 93~98%, can be more preferably 93.5~97.5%.
In addition, it is necessary to by being 2~7% as the acicular bainite of hard phase and the total control of cementite.When needle-shaped bayesian
When body and cementite are added up to less than 2%, with rigid reduction, the thickness of flux-cored wire rises, when acicular bainite and cementite
When adding up to more than 7%, processability is deteriorated.Therefore, bainite and cementite total preferably 2~7%, can be more preferably 2.5
~6.5%.
At this point, the yield strength of cold-rolled steel sheet according to the present invention can be 200~300MPa, and its elongation percentage can be with
It is 40% or more.By meeting these physical properties, flux-cored wire material can be preferably adapted for.
When yield strength is less than 200MPa, Guan Keneng bends, when yield strength is more than 300MPa, although in pipe
Voltage endurance in terms of be advantageous, but due to intensity rise, tubing reduce, and due to the wear intensity of machining tool increase
Add and manufacturing cost rising.
When elongation percentage is less than 40%, tubing processability is deteriorated, so that the cracking such as tearing may occur in processing.
In addition, the weld part segregation index of cold-rolled steel sheet according to the present invention can be 0.15% or less.
More specifically, the weld part for indicating the flux-cored wire by manufacturing using cold-rolled steel sheet according to the present invention to weld
Segregation index.Weld part segregation index can indicate shared by the entire area of weld part and the segregation portion based on addition element
Area ratio.
When weld part is segregated, stress concentrates on segregation portion when processing, to become the reason of being broken.For
Tearing caused by being segregated when second is processed after welding by weld part is prevented, the segregation index of weld part is preferably 0.15%
Below.
In existing flux-cored wire, in order to ensure low-temperature flexibility, the alloy member as solder flux such as nickel (Ni) elements is added
Element rather than base material, therefore weld part segregation index rise, but utilize cold-rolled steel sheet according to the present invention when, substantially reduce as
The upper segregation reason, therefore segregation index can be ensured below 0.15%.
The manufacturing method of flux-cored wire cold-rolled steel sheet
In the following, the manufacturing method of the flux-cored wire cold-rolled steel sheet of another aspect of the present invention is described in detail.
The manufacturing method of the flux-cored wire cold-rolled steel sheet of another aspect of the present invention will be the following steps are included: will have described
The heating of plate blank of composition of alloy is to 1100~1300 DEG C；Hot rolling is carried out to the slab of heating, until hot finishing temperature reaches
880~950 DEG C, to obtain hot rolled steel plate；Under 550~700 DEG C of temperature range, the hot rolled steel plate is wound；With 50~
85% reduction ratio carries out cold rolling to the hot rolled steel plate of winding, to obtain cold-rolled steel sheet；And to the cold-rolled steel sheet into
Row continuous annealing.
Heating of plate blank step
By the heating of plate blank with the composition of alloy to 1050~1300 DEG C.This is to be smoothly performed subsequent heat
Roll process, and homogenize process is executed to slab.
When slab heating temperature is less than 1050 DEG C, in subsequent hot rolling, loading is sharply increased, and on the other hand, works as slab
When heating temperature is more than 1300 DEG C, energy cost increases, and the amount of surface scale increases, so as to cause material to damage
It loses.
Hot-rolled step
Hot rolling is carried out to the slab of heating, until hot finishing temperature reaches 880~950 DEG C, to obtain hot rolled steel plate.
When final rolling temperature is less than 880 DEG C, with terminating in low-temperature region hot rolling, the mixed granulation of crystal grain is sharply carried out, from
And hot rolling and processability is caused to reduce.On the other hand, when final rolling temperature is more than 950 DEG C, there is no real in whole thickness
Now uniform hot rolling, so that crystal grain miniaturization is insufficient, it is thus possible to occur under the impact flexibility as caused by coarse grains
Drop.
Wind step
The hot rolled steel plate is wound under 550~700 DEG C of temperature range.At this point, the hot-rolled steel after hot rolling and before winding
The cooling of plate can execute on runout table (Run-out-table, ROT).
It is uneven due to width direction temperature during cooling and holding when winding temperature less than 550 DEG C, it generates low
The trend of warm precipitate shows difference, so as to cause material deviation, therefore generates deleterious effect to processability.Another party
Face, when winding temperature is more than 700 DEG C, with the organizational coarseness of final products, Facing material softening and tubing variation.
Cold rolling step
Cold rolling is carried out with the hot rolled steel plate of 50~85% reduction ratio to winding, to obtain cold-rolled steel sheet.
When reduction ratio is less than 50%, recrystallization driving force is low, and the growth etc. of local organization occurs, and therefore, it is difficult to ensure
Uniform material, and consider the thickness of final products, need to reduce the thickness of hot rolled steel plate, therefore hot-rolled manipulation is significant
It reduces.On the other hand, when reduction ratio is more than 85%, material solidification becomes the reason of being cracked in drawing, not only such as
This, due to the load of roll mill, and reduces cold rolling manipulation.
Therefore, reduction ratio is preferably 50~85%, can be more preferably 65~80%.
At this point, can also include the steps that the hot rolled steel plate that pickling is wound before cold rolling.
Continuous annealing step
Continuous annealing is carried out to the cold-rolled steel sheet in order to ensure processability and rigidity.Pass through the change introduced in cold rolling
Shape and the annealing that deformation is removed in the state of intensity increase, so that it is guaranteed that target strength and processability.
At this point, the continuous annealing can execute under 700~850 DEG C of temperature range.
Under the annealing temperature less than 700 DEG C, as no sufficiently removal deforms, processability is significantly reduced.On the other hand,
Under the annealing temperature more than 850 DEG C, the continuous annealing furnace based on high annealing, which leads on plate, may occur problem.
At this point it is possible to the cold-rolled steel sheet of the cooling continuous annealing of 30~60 DEG C/sec of cooling velocity.This is because
When cooling velocity is more than 60 DEG C/sec, a large amount of acicular bainite and cementite are generated, so as to become in tubing and drawing
The reason of being broken when processing as material softens, rigidly may be decreased, therefore medicine when cooling velocity is less than 30 DEG C/sec
The thickness of core welding wire may rise.
Specific embodiment
In the following, by embodiment, the present invention will be described in more detail.However, it is noted that following embodiment is only
For illustrating and being described in more detail the present invention, and interest field of the invention is not limited.This is because right of the invention
Content that range is rationally derived by the content recorded in claims and thus determines.
By with shown in following table 1 at the heating of plate blank being grouped as to after 1250 DEG C, recorded according in following table 2
Manufacturing condition manufacture cold-rolled steel sheet.Cooling velocity after continuous annealing is 40 DEG C/sec.
It measures logical plate, yield strength, elongation percentage, processability and the microstructure of the cold-rolled steel sheet and is documented in following
In table 3.
In addition, measuring the weld part welded by the low-temperature flexibility manufactured using the cold-rolled steel sheet with flux-cored wire
It is segregated index, and is documented in following Table 3.It is that Ni contains in the entire alloying component with flux-cored wire for each situation
It measures and solder flux composition is set for 1.5% mode, the welding wire that manufacture diameter is 1.4mm simultaneously uses experiment guide (Pilot) welding machine,
Under conditions of voltage is 29V, electric current is 150~180A, speed of welding per minute is 14cm, implement using shipbuilding with steel band as object
The result of soldering test.
For yield strength shown in table 3, elongation percentage, if respectively meet 200~300MPa range yield strength,
Each target fiducials of 40% or more elongation percentage and the segregation index less than 0.15%, then it represents that be " O ", if being unable to satisfy each spy
Property benchmark, then it represents that be " X ".
In addition, for processability, when carrying out drawing processing to cold-rolled steel sheet with 45% section slip, if it happens
The manufacturing deficiencies such as tearing, then it represents that be " bad ", if there is no manufacturing deficiencies, then it represents that be " good ".
For leading to plate, if there is no rolling load in cold rolling and hot rolling and that there is no hot wooden dippers in continuous annealing is bent
The defects of (Heat buckle), then it represents that be " O ", if generate rolling load or hot wooden dipper song occurs in continuous annealing etc.
Defect, then it represents that be " X ".
[table 1]
[table 2]
[table 3]
Meet material base of the satisfaction of example 1 to 9 of the composition of alloy and manufacturing condition that propose in the present invention as target
The elongation percentage of the quasi- yield strength and 40% of 200~300MPa or more, and drawing processability and logical plate are good.In addition,
The segregation index of weld part is again smaller than 0.15%, and there is no the tearing of weld part or crackings when processing for second, thus
It may insure excellent processability.
It has been confirmed that meeting composition of alloy and manufacture item of the invention such as in Fig. 1 of the microstructure of shooting example 2
Part, so as to ensure microstructure of the invention.
Although comparative example 1 to 4 meets the composition of alloy proposed in the present invention, do not meet manufacturing condition, it can be true
Recognize, the yield strength of comparative example 1 to 4 is high and elongation percentage is poor, and drawing processability is also poor.Further, it was observed that comparative example 1 and 2
Logical plate it is also bad, and the microstructure of comparative example 1 be formed as deform grain, i.e. ferrite (the deformed of non-recrystallization
Ferrite), the part in comparative example 2 in addition to 42.3% is deformation grain.
Comparative example 5 to 10 meets the manufacturing condition proposed in the present invention, but does not meet composition of alloy.Due to all
In the case where do not meet Material texture and weld part segregation index, therefore at second of the drawing processing of welding wire and weld part
It is torn or is cracked when processing.
In addition, by do not ensure logical plate (comparative example 10), yield strength be detached to be obtained in the present invention 200~
300MPa degree (comparative example 5 and comparative example 7 to 10), elongation percentage do not meet targeted degree (comparative example 6 to 10), and can not expire
Foot needs the target property of the flux-cored wire cold-rolled steel sheet of processability and low-temperature flexibility.
Referring to Fig. 2 of the microstructure of shooting comparative example 6, it can be confirmed that the ferrite to be formed is more than 98 area %.
As described above, according to the present invention, significantly improving the segregation of weld part by control composition of alloy and manufacturing condition
Occur, and improve the content of other solder flux elements by reducing the Ni content in solder flux, it is hereby ensured that low-temperature flexibilities
The characteristic of excellent flux-cored wire cold-rolled steel sheet with welding operability.Therefore, cold-rolled steel sheet of the invention is utilized, it is possible to reduce
As process costs rise the reason of solder flux in Ni content, and can according to substantially reduce in weld part be segregated reduce weldering
The cracking that socket part occurs, moreover, it can be ensured that the stable operability of product, therefore the material that can reduce product occurs
Deviation, to be also effective in terms of saving cost and improving operability.
Above by reference to embodiment, the present invention is described, still, this hair recorded in not departing from claims
In the range of bright technical idea and technical field, various modifications can be carried out and deformation, this is for the common of the art
It is obvious for technical staff.
Claims (9)
1. a kind of flux-cored wire cold-rolled steel sheet, the flux-cored wire cold-rolled steel sheet includes in terms of weight %: C:0.01~
0.15%, Mn:0.1~0.5%, Si:0.05% or less (except 0%), P:0.0005~0.01%, S:0.008% or less
(except 0%), Al:0.005~0.06%, N:0.0005~0.003%, Ni:0.5~2.0% and surplus Fe and can not keep away
The impurity exempted from, in terms of area fraction, microstructure includes 93~98% ferrite, and adds up to the needle-shaped shellfish comprising 2~7%
Family name's body and cementite.
2. flux-cored wire cold-rolled steel sheet according to claim 1, which is characterized in that
In the cold-rolled steel sheet, with the W of the definition of relational expression 1FCIt is 0.5~4.5,
Relational expression 1:WFC=(25*C+0.4*Mn+26*Al) * Ni
The unit of each element content is weight % in the relational expression 1.
3. flux-cored wire cold-rolled steel sheet according to claim 1, which is characterized in that
The yield strength of the cold-rolled steel sheet is 200~300MPa, and elongation percentage is 40% or more.
4. flux-cored wire cold-rolled steel sheet according to claim 1, which is characterized in that
The weld part segregation index of the cold-rolled steel sheet is less than 0.15%.
5. a kind of manufacturing method of flux-cored wire cold-rolled steel sheet, comprising the following steps:
By heating of plate blank to 1100~1300 DEG C, the slab includes in terms of weight %: C:0.01~0.15%, Mn:0.1~
0.5%, Si:0.05% or less (except 0%), P:0.0005~0.01%, S:0.008% or less (except 0%), Al:0.005
~0.06%, the Fe of N:0.0005~0.003%, Ni:0.5~2.0% and surplus and inevitable impurity；
Hot rolling is carried out to the slab of heating, until hot finishing temperature reaches 880~950 DEG C, to obtain hot rolled steel plate；
Under 550~700 DEG C of temperature range, the hot rolled steel plate is wound；
With 50~85% reduction ratio, cold rolling is carried out to the hot rolled steel plate of winding, to obtain cold-rolled steel sheet；And
Continuous annealing is carried out to the cold-rolled steel sheet.
6. the manufacturing method of flux-cored wire cold-rolled steel sheet according to claim 5, which is characterized in that
In the slab, with the W of the definition of relational expression 1FCIt is 0.5~4.5,
Relational expression 1:WFC=(25*C+0.4*Mn+26*Al) * Ni
The unit of each element content is weight % in the relational expression 1.
7. the manufacturing method of flux-cored wire cold-rolled steel sheet according to claim 5, which is characterized in that
The continuous annealing executes under 700~850 DEG C of temperature range.
8. the manufacturing method of flux-cored wire cold-rolled steel sheet according to claim 5, which is characterized in that
Further include the steps that the hot rolled steel plate that pickling is wound before the cold rolling.
9. the manufacturing method of flux-cored wire cold-rolled steel sheet according to claim 7, which is characterized in that
With 30~60 DEG C/sec of cooling velocity, the cold-rolled steel sheet of cooling continuous annealing.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020160131475A KR101795970B1 (en) | 2016-10-11 | 2016-10-11 | Cold-rolled steel sheet for flux cored wire and manufacturing the same |
| KR10-2016-0131475 | 2016-10-11 | ||
| PCT/KR2017/011122 WO2018070753A1 (en) | 2016-10-11 | 2017-10-11 | Cold rolled steel sheet for flux cored wire, and manufacturing method therefor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109804092A true CN109804092A (en) | 2019-05-24 |
| CN109804092B CN109804092B (en) | 2020-10-20 |
Family
ID=60385574
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201780062649.8A Active CN109804092B (en) | 2016-10-11 | 2017-10-11 | Cold-rolled steel sheet for flux-cored wire and method for manufacturing same |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP6811854B2 (en) |
| KR (1) | KR101795970B1 (en) |
| CN (1) | CN109804092B (en) |
| WO (1) | WO2018070753A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102134310B1 (en) * | 2017-12-26 | 2020-07-15 | 주식회사 포스코 | Cold-rolled steel sheet for flux cored wire and manufacturing the same |
| KR102112172B1 (en) * | 2018-06-01 | 2020-05-18 | 주식회사 포스코 | Cold-rolled steel sheet for flux cored wire and manufacturing the same |
| KR102353730B1 (en) * | 2019-12-20 | 2022-01-19 | 주식회사 포스코 | Cold-rolled steel sheet for flux cored wire and manufacturing the same |
| CN112760462A (en) * | 2020-12-17 | 2021-05-07 | 包头钢铁（集团）有限责任公司 | Preparation method of steel for flux-cored wire |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6240996A (en) * | 1985-08-20 | 1987-02-21 | Nippon Steel Corp | Submerged arc welding wire for low-temperature steel |
| JP2005349466A (en) * | 2004-06-14 | 2005-12-22 | Kobe Steel Ltd | Weld metal, welding wire, and electroslag welding method |
| CN101224527A (en) * | 2008-02-04 | 2008-07-23 | 湘潭大学 | High hardness ferritic stainless steel wearable surfacing flux-cored wire |
| JP2009028765A (en) * | 2007-07-27 | 2009-02-12 | Kobe Steel Ltd | Weld metal and titania-based flux cored wire |
| KR20090070147A (en) * | 2007-12-26 | 2009-07-01 | 주식회사 포스코 | Flux cored arc weld metal joint having superior ctod in low temperature |
| CN103276287A (en) * | 2013-06-08 | 2013-09-04 | 济钢集团有限公司 | Cold-rolled steel strip for high-drawing-performance flux-cored wire, and making method thereof |
| CN103436778A (en) * | 2013-08-23 | 2013-12-11 | 首钢总公司 | Cold-strip steel with low-temperature toughness for flux-cored wires and production method of cold-strip steel |
| CN104741834A (en) * | 2015-03-06 | 2015-07-01 | 西安理工大学 | Flux-cored wire for welding X90 pipeline steel and preparing method thereof |
| CN104903046A (en) * | 2012-12-27 | 2015-09-09 | Posco公司 | Ultra high strength flux cored arc welded joint having excellent impact toughness and welding wire for manufacturing same |
| CN104946970A (en) * | 2015-06-09 | 2015-09-30 | 唐山钢铁集团有限责任公司 | Production method of steel for thin diameter pipe-shaped flux-cored wire |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61253195A (en) * | 1985-04-30 | 1986-11-11 | Daido Steel Co Ltd | Flux cored wire for welding |
| JPS632592A (en) * | 1986-06-19 | 1988-01-07 | Kobe Steel Ltd | Flux cored wire for low alloy heat resistant steel welding |
| JPH01294822A (en) * | 1988-05-23 | 1989-11-28 | Sumitomo Metal Ind Ltd | Manufacture of cold rolled steel plate for flux cored wire electrode |
| JP2687006B2 (en) * | 1989-02-18 | 1997-12-08 | 新日本製鐵株式会社 | Flux-cored wire for gas shielded arc welding for refractory steel |
| KR20040050294A (en) * | 2002-12-10 | 2004-06-16 | 고려용접봉 주식회사 | Flux cored wire for ferritic stainless steel |
| JP5005309B2 (en) * | 2006-10-02 | 2012-08-22 | 株式会社神戸製鋼所 | Gas shielded arc welding flux cored wire for high strength steel |
| JP5157606B2 (en) * | 2008-04-10 | 2013-03-06 | 新日鐵住金株式会社 | TIG welding method of high strength steel using flux cored wire |
| JP5411820B2 (en) * | 2010-09-06 | 2014-02-12 | 株式会社神戸製鋼所 | Flux-cored welding wire and overlay welding arc welding method using the same |
| KR101033389B1 (en) | 2011-01-04 | 2011-05-09 | 현대하이스코 주식회사 | Steel sheet for flux cord wire and it's manufacturing method |
| KR101377771B1 (en) * | 2011-12-29 | 2014-03-26 | 현대제철 주식회사 | Steel sheet for flux cord wire and method for manufacturing the steel sheet |
| KR101400600B1 (en) * | 2013-08-05 | 2014-05-27 | 현대제철 주식회사 | Pickling and oiling steel sheet for welding electrode with excellent low temperature toughness, flux cored wire welding electrode for offshore plant and method of manufacturing the same |
-
2016
- 2016-10-11 KR KR1020160131475A patent/KR101795970B1/en active IP Right Grant
-
2017
- 2017-10-11 WO PCT/KR2017/011122 patent/WO2018070753A1/en active Application Filing
- 2017-10-11 CN CN201780062649.8A patent/CN109804092B/en active Active
- 2017-10-11 JP JP2019519335A patent/JP6811854B2/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6240996A (en) * | 1985-08-20 | 1987-02-21 | Nippon Steel Corp | Submerged arc welding wire for low-temperature steel |
| JP2005349466A (en) * | 2004-06-14 | 2005-12-22 | Kobe Steel Ltd | Weld metal, welding wire, and electroslag welding method |
| JP2009028765A (en) * | 2007-07-27 | 2009-02-12 | Kobe Steel Ltd | Weld metal and titania-based flux cored wire |
| KR20090070147A (en) * | 2007-12-26 | 2009-07-01 | 주식회사 포스코 | Flux cored arc weld metal joint having superior ctod in low temperature |
| CN101224527A (en) * | 2008-02-04 | 2008-07-23 | 湘潭大学 | High hardness ferritic stainless steel wearable surfacing flux-cored wire |
| CN104903046A (en) * | 2012-12-27 | 2015-09-09 | Posco公司 | Ultra high strength flux cored arc welded joint having excellent impact toughness and welding wire for manufacturing same |
| CN103276287A (en) * | 2013-06-08 | 2013-09-04 | 济钢集团有限公司 | Cold-rolled steel strip for high-drawing-performance flux-cored wire, and making method thereof |
| CN103436778A (en) * | 2013-08-23 | 2013-12-11 | 首钢总公司 | Cold-strip steel with low-temperature toughness for flux-cored wires and production method of cold-strip steel |
| CN104741834A (en) * | 2015-03-06 | 2015-07-01 | 西安理工大学 | Flux-cored wire for welding X90 pipeline steel and preparing method thereof |
| CN104946970A (en) * | 2015-06-09 | 2015-09-30 | 唐山钢铁集团有限责任公司 | Production method of steel for thin diameter pipe-shaped flux-cored wire |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6811854B2 (en) | 2021-01-13 |
| WO2018070753A1 (en) | 2018-04-19 |
| KR101795970B1 (en) | 2017-11-09 |
| CN109804092B (en) | 2020-10-20 |
| JP2019534382A (en) | 2019-11-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5177310B2 (en) | High tensile strength steel sheet with excellent low temperature toughness of weld heat affected zone and method for producing the same | |
| JP5924058B2 (en) | High tensile strength steel sheet with excellent low temperature toughness of weld heat affected zone and method for producing the same | |
| JP5950045B2 (en) | Steel sheet and manufacturing method thereof | |
| CN101381845B (en) | High-purity ferrite stainless steel material and manufacturing method thereof | |
| CN109706391A (en) | A kind of 60 kg class high-strength welding wire gren rod and its production method | |
| WO1994022606A1 (en) | Wear- and seizure-resistant roll for hot rolling | |
| WO2017056618A1 (en) | High-strength stainless steel sheet having excellent fatigue characteristics, and method for manufacturing same | |
| CN109804092A (en) | Flux-cored wire cold-rolled steel sheet and its manufacturing method | |
| JP6259336B2 (en) | Ni-based alloy and method for producing the same | |
| JP6245352B2 (en) | High-tensile steel plate and manufacturing method thereof | |
| CN102950392A (en) | Wire rod for production of pipeline submerged arc welding wires and method for manufacturing wire rod | |
| US11220732B2 (en) | Ferritic stainless steel sheet | |
| KR101971772B1 (en) | Method of manufacturing steel plate for high-heat input welding | |
| CN102933732B (en) | The excellent structure stainless steel plate of corrosion resistance at welded part and its manufacture method | |
| KR100856306B1 (en) | Ferritic stainless steel having excellent low temperature formability of welded zone | |
| JP6926247B2 (en) | Cold-rolled steel sheet for flux-cored wire and its manufacturing method | |
| JP4998365B2 (en) | Ultra-low carbon steel sheet and manufacturing method thereof | |
| KR102112172B1 (en) | Cold-rolled steel sheet for flux cored wire and manufacturing the same | |
| JP2012046815A (en) | METHOD FOR PRODUCING Zr-CONTAINING STEEL | |
| CN111542634A (en) | Cold-rolled steel sheet for flux-cored wire and method for manufacturing same | |
| JP2001335882A (en) | Mg-CONTAINING STEEL FOR EXTREMELY HIGH HEAT INPUT WELDING | |
| JP2013039589A (en) | Filler metal and build-up metal member using the same | |
| CN117102657A (en) | Stainless steel easy-to-weld high-strength steel composite blank, composite material and preparation method | |
| JP5815291B2 (en) | Stainless steel for welding | |
| KR20230092609A (en) | Cold-rolled steel sheet with excellent weldability and method of manufacturing 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address |
Address after: Seoul, South Kerean Patentee after: POSCO Holdings Co.,Ltd. Address before: Gyeongbuk, South Korea Patentee before: POSCO |
|
| CP03 | Change of name, title or address | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20230607 Address after: Gyeongbuk, South Korea Patentee after: POSCO Co.,Ltd. Address before: Seoul, South Kerean Patentee before: POSCO Holdings Co.,Ltd. |
|
| TR01 | Transfer of patent right |