EP3392364A1 - Hochharter abriebfester stahl mit hervorragender festigkeit und schneidrissbeständigkeit und verfahren zur herstellung davon - Google Patents

Hochharter abriebfester stahl mit hervorragender festigkeit und schneidrissbeständigkeit und verfahren zur herstellung davon Download PDF

Info

Publication number
EP3392364A1
EP3392364A1 EP16875937.1A EP16875937A EP3392364A1 EP 3392364 A1 EP3392364 A1 EP 3392364A1 EP 16875937 A EP16875937 A EP 16875937A EP 3392364 A1 EP3392364 A1 EP 3392364A1
Authority
EP
European Patent Office
Prior art keywords
present
resistant steel
less
high hardness
steel
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
Application number
EP16875937.1A
Other languages
English (en)
French (fr)
Other versions
EP3392364A4 (de
EP3392364B1 (de
Inventor
Il-Cheol YI
Yong-Jin Kim
Sung-Kyu Kim
Sang-Deok Kang
Un-Hae LEE
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Posco Holdings Inc
Original Assignee
Posco Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Posco Co Ltd filed Critical Posco Co Ltd
Publication of EP3392364A4 publication Critical patent/EP3392364A4/de
Publication of EP3392364A1 publication Critical patent/EP3392364A1/de
Application granted granted Critical
Publication of EP3392364B1 publication Critical patent/EP3392364B1/de
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • 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
    • 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
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • 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
    • C22C38/02—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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite

Definitions

  • the present invention relates to a high hardness wear-resistant steel with excellent toughness and cutting crack resistance, and a method for manufacturing the same.
  • the present invention claims benefit of priority to Korean Patent Application No. 10-2015-0179009 , the disclosure of which is incorporated herein by reference in its entirety.
  • Wear-resistant steels have to have a high surface hardness.
  • High hardness martensitic steels have high hardness as well as high yield strength and tensile strength to be widely used for structural materials, transportation/construction machines, and the like.
  • a steel composition contains a large amount of alloying elements and high carbon to secure so-called quenchability, and a quenching operation in a manufacturing process may be essentially included, to produce high hardness martensitic steels.
  • An aspect of the present invention may provide a high hardness wear-resistant steel having high toughness and cutting crack resistance while relatively reducing the addition amount of alloying elements, such as carbon (C), or the like, which may adversely affect toughness, or the like of the wear-resistant steel.
  • alloying elements such as carbon (C), or the like
  • Another aspect of the present invention may provide a manufacturing method for efficiently producing the above-mentioned high-hardness wear-resistant steel.
  • a high hardness wear-resistant steel has a composition containing, by weight ratio, 2.1 to 4.0% of manganese (Mn), 0.15 to 0.2% of carbon (C), 0.02 to 0.5% of silicon (Si), 0.2 to 0.7% of chromium (Cr), a remainder of Fe and other unavoidable impurities, has a microstructure in which prior austenite grain size is 25 ⁇ m or less and martensite is included as a main phase, and satisfies a condition in which Ac3-Ac1 is 100°C or lower.
  • Mn manganese
  • C carbon
  • Si silicon
  • Cr chromium
  • a method of manufacturing a high hardness wear-resistant steel includes: hot-rolling a slab having a composition containing, by weight ratio, 2.1 to 4.0% of manganese (Mn), 0.15 to 0.2% of carbon (C), 0.02 to 0.5% of silicon (Si), 0.2 to 0.7% of chromium (Cr), a remainder of Fe and other unavoidable impurities, to provide a steel plate, quenching the steel plate to a temperature of 200°C or lower at a cooling rate of 3°C/sec or higher, reheating the quenched steel plate to an austenite temperature range, and secondarily quenching the reheated steel plate to a temperature of 200°C or lower at a cooling rate of 3°C/sec or higher.
  • the present invention may provide steel having high toughness and high cutting crack resistance while maintaining hardness of the steel at a 450HB level, by increasing an amount of manganese (Mn) and conducting ultra-refinement of grains, instead of optimizing an amount of carbon (C) in the steel.
  • Mn manganese
  • C carbon
  • an amount of carbon (C) in steel may be adjusted to be within an appropriate range to ensure a low-temperature toughness of a wear-resistant steel, and a large amount of manganese (Mn) may be added to secure quenchability. Further, alloying components may be appropriately controlled to secure cutting crack resistance.
  • C carbon
  • Mn manganese
  • a wear-resistant steel according to the present invention may have a composition, by weight ratio, containing 2.1 to 4.0% of manganese (Mn), 0.15 to 0.2% of carbon (C), 0.02 to 0.5% of silicon (Si), 0.2 to 0.7% of chromium (Cr), a remainder of iron (Fe) and other unavoidable impurities. It should be noted that amounts of each component in the present invention may be expressed on the basis of weight unless otherwise specified.
  • Manganese (Mn) may be an element added to stabilize martensite and obtain high surface hardness.
  • manganese (Mn) may be added in an amount of 2.1% or more to obtain this effect.
  • an amount of manganese (Mn) is insufficient, ferrite or bainite may be easily produced, and high hardness of a surface layer may thus be difficult to obtain.
  • an amount of manganese (Mn) exceeds 4.0%, not only weldability and cutting crack resistance may be remarkably reduced, but manufacturing costs of the steel may also be significantly reduced. Therefore, in the present invention, an amount of manganese (Mn) may be added in the range of 2.1 to 4.0%.
  • Carbon (C) may be an element added to secure hardness of a surface layer in the steel, similar to manganese (Mn). However, when an amount thereof is excessively high, there may be a problem in which toughness and weldability are significantly lowered, such that the amount is required to be controlled within an appropriate range. In the present invention, 0.15% or more of carbon (C) may be added to ensure sufficient hardness of a surface layer. However, the upper limit of the amount may be 0.20% since toughness and weldability may be deteriorated when Mn is added in an excessively high amount.
  • Silicon (Si) may be an element added to serve as a deoxidizing agent, and may improve strength by solid solution strengthening.
  • a lower limit of an amount of Silicon (Si) may be set to be 0.02%.
  • the amount is excessively high, toughness of a base material as well as that of a welded portion may be significantly reduced, such that the amount may be limited to 0.5% or less.
  • chromium (Cr) When chromium (Cr) is included in steel, it may serve a role in raising the hardenability of the steel to facilitate securing martensite when quenching. Further, in the wear-resistant steel of the present invention, as the amount thereof increases, impact toughness at low temperature may be improved, and an interval between an Ac1 and an Ac3, phase transformation temperatures, may be narrowed to improve cutting cracking resistance. The amount thereof may be advantageously 0.2% or more to obtain such an advantageous effect of chromium (Cr) . When the amount is excessively high, there may be a risk of lowering the weldability and raising the manufacturing cost, such that upper limit of the amount of chromium (Cr) may be set to be 0.7%.
  • the wear-resistant steel of the present invention may further contain 0.1% or less of niobium (Nb), 0.02% or less of boron (B), and 0.1% or less of titanium (Ti), in addition to the above-described alloying elements.
  • Nb niobium
  • B boron
  • Ti titanium
  • Niobium (Nb) may be an element increasing the strength of steel by effects of solid solution strengthening, precipitation hardening, or the like, and improves impact toughness by conducting grain refinement, and may be added as needed. When the amount is excessively high, coarse precipitates may be formed to deteriorate hardness and impact toughness, such that the amount thereof may be limited to 1.0% or less.
  • Boron (B) may be an element that effectively increases quenchability of a material even with a small amount of addition, and has an effect of inhibiting grain boundary fractures by strengthening grain boundaries, and may be added and used as needed.
  • the amount thereof may preferably be limited to 0.02% or less.
  • Nitrogen (N) may be mentioned as an impurity element which may be inevitably included in steel.
  • nitrogen (N) is combined with boron (B)
  • Titanium (Ti) may be an element which is effective in suppressing the decrease of the effect of boron (B) by nitrogen (N), and significantly increasing the addition effect of boron (B).
  • titanium (Ti) may react with nitrogen (N) present in steel to form TiN, thereby suppressing formation of BN.
  • TiN may also have the effects of pinning austenite grains, and suppressing coarsening of the grains. Therefore, in the present invention, titanium (Ti) may be added in the steel as required. When the addition amount of titanium (Ti) may be excessively high, coarse precipitates may be formed to lower toughness and weldability, such that the amount thereof may be limited to 0.1% or less.
  • One of remainder components of the present invention may be iron (Fe) . Since impurities, which are not intended, may be inevitably incorporated from raw material or surrounding environment in the conventional steel manufacturing process, the wear-resistant steel of the present invention does not specifically exclude the impurities. The kinds and amounts of these impurities are not particularly limited in the present invention, since they may be known to any one of ordinary skill in the art.
  • the wear-resistant steel of the present invention may have a value of Ac3-Ac1 of 100°C or lower, in addition to the above-mentioned composition system, to improve cutting crack resistance.
  • the cutting crack generated at the time of gas cutting may be a kind of hydrogen induced crack, and may be characterized by the fact that it is more likely to occur as residual stress generated in a heat affected zone (in particular, ICHAZ) is relatively high. Therefore, reducing the residual stress of the heat affected zone may be one means of improving crack resistance.
  • it may be proposed to adjust the value of Ac3-Acl for this purpose.
  • an Ac3 is a temperature at which pro-eutectoid ferrite begins to be generated in austenite during cooling
  • an Ac1 is a temperature at which a structure is entirely transformed into ferrite.
  • the residual stress of the ICHAZ InterCritical Heat Affected Zone
  • the occurrence of cracks in this zone may be reduced.
  • a large value of Ac3-Acl means that the 2 phase temperature region in which austenite and ferrite coexist may be relatively wide.
  • FIG. 1 shows the results of an EBSD (Electron Back Scatter Diffraction) analysis of the heat affected zone formed during gas cutting.
  • EBSD Electro Back Scatter Diffraction
  • a Kernal average misorientation map showing the heat affected zone of the welded portion is observed in an upper portion of the figure, while a concentration region of the residual stress is observed in a lower portion of the figure.
  • the present inventors have found that red color appears to be the most concentrated in ICHAZ, thus the present inventors could understand that residual stress may be concentrated in the ICHAZ. Therefore, when the value of Ac3-Ac1, which may be effective for reducing a size of the ICHAZ, may be controlled to be 100°C or lower, excellent cutting crack resistance may be obtained.
  • the value of Ac3-Ac1 may be limited to 100°C or lower.
  • the wear-resistant steel according to another aspect of the present invention has an internal structure in which prior austenite grain size in a surface is 25 ⁇ m or less and a martensite phase may be included as a main phase.
  • the term 'main phase' means a phase having the highest occupancy rate in terms of an area fraction.
  • the wear-resistant steel of the present invention may contain 95% or more of a martensite phase in an area fraction. That is, the martensite phase having a fine particle size has an effect of improving low-temperature toughness.
  • the fraction of martensite may be preferably 95% or more to achieve high hardness and excellent wear resistance.
  • the prior austenite grain size may be obtained by observing a structure eroded with the picric acid etchant under an optical microscope (for example, having a magnification of 200 times), and using the value calculated according to the provisions of JIS G0551.
  • the wear-resistant steel of the present invention may have fine grain and thus have excellent toughness . Therefore, there may be no need for an additional tempering operation to secure toughness to be desired. Therefore, in the martensite phase of the wear-resistant steel of the present invention, there may be substantially no carbide-based precipitate present.
  • the phrase, for example, there may be no carbide-based precipitate present means that the martensite phase substantially does not include carbide-based precipitates in the present invention.
  • the thickness of the steel plate may be in the range of 80 mm or less to secure core hardness up to 400HB.
  • thickness of the wear-resistant steel may be set to be 3 mm or more, considering that the wear-resistant steel may be produced by hot-rolling.
  • the wear-resistant steel of the present invention satisfying such conditions may have a value of 420 to 480 on the basis of Brinell hardness, and may have excellent toughness with Charpy impact energy of 35 J or more at -40°C.
  • the wear-resistant steel of the present invention may have a cutting crack resistance that does not cause cutting crack, even after a week or more in which, for example, a steel plate having a thickness of 11 mm is cut by 400 mm or more under a condition of not preheating at the time of gas cutting and a cutting speed of 500 mm/min.
  • the wear-resistant steel of the present invention may not only have high wear resistance without substantially adding alloying elements such as Mo, Ni, or the like, added to increase wear resistance in wear-resistant steel, but also excellent toughness and cutting crack resistance.
  • one advantageous method for producing the wear-resistant steel of the present invention may be proposed as follows. For example, in the method of manufacturing a wear-resistant steel of the present invention, after a steel material may be hot-rolled, quenching may be performed to obtain a martensite phase, followed by heating to an austenite temperature range, and then quenching. Each process will be described in more detail as follows.
  • Hot-rolling process may be carried out by a conventional method.
  • hot-rolling finishing temperature may be set in the range of an Ar3 to 900°C on the surface portion basis to be suitable for the subsequent quenching process. That is, when hot-rolling is performed at a temperature lower than an Ar3, ferrite may be excessively formed in steel, which may result in a problem in which an intended structure may not be obtained in a subsequent quenching process, such that the hot-rolling end temperature may be made to be an Ar3 or higher.
  • the hot-rolling end temperature may be set to be 800°C or higher.
  • the hot-rolling end temperature may be set to 900°C or lower.
  • the steel may be immediately quenched immediately after hot-rolling.
  • 'immediately' means that the surface temperature of the steel may start to be quenched without falling below the austenite formation temperature.
  • martensite transformation occurs in a state in which grains are refined by hot-rolling, such that the obtained martensite phase may be refined.
  • Quenching immediately after hot-rolling of the present invention may be performed by quenching at a cooling rate of 3°C/sec or higher until the center temperature of the steel becomes 200°C or lower (according to one aspect, to a temperature selected from ambient temperature to 200°C) .
  • the cooling rate may be set to be within the range of 50°C/sec or less in consideration of the conventional quenching process.
  • the steel hot-rolled by the above-mentioned process may be transformed from austenite to a martensite phase.
  • the hot-rolled and quenched steel may then be subjected to a reheating process.
  • the steel including the martensite phase is heated to be within an austenite temperature range, since the inner packet boundary of the already formed martensite phase functions as a nucleation site of the austenite phase, austenite nucleation occurs in many locations.
  • the resulting austenite grains may be very refined in size.
  • the quenched steel it may be necessary to heat the quenched steel to a temperature equal to or higher than an Ac3 with respect to the center.
  • the heating temperature is relatively high, the austenite grain size may increase again, such that upper limit of the heating temperature may be set to be 960°C.
  • the heat treatment time (also referred to as a soaking time) after the center of the steel plate reaches the Ac3 temperature may be maintained at 120 minutes or less. Considering a sufficient heat treatment effect, it may take 20 minutes or more. However, the time may vary slightly depending on the thickness of the steel plate, and may be maintained for a longer time, when the thickness of the steel plate is relatively high.
  • the austenitized steel according to the preceding process may be cooled to a temperature of 200°C or lower (a temperature between ambient temperature and 200°C, according to one aspect) at a cooling rate of 3°C/sec or higher at the center portion.
  • the wear-resistant steel of the present invention may be formed with a martensite phase having a fine particle size in a proportion of 95% or more in area fraction.
  • the austenite phase immediately before the secondary quenching may have a grain size of 25 ⁇ m or less.
  • the fine packet size of the final martensite phase may be obtained by making the austenite phase immediately before the secondary quenching fine.
  • the size of the austenite phase immediately before the secondary quenching may be confirmed by measuring prior austenite grain size of the finally obtained steel.
  • the upper limit of the cooling rate in the secondary quenching process may be not particularly limited, but may be limited to 50°C/sec or less in one aspect of the present invention.
  • the wear-resistant steel produced by the manufacturing method of the present invention may have cutting crack resistance that does not cause cutting crack, even after a week or more that, for example, a steel plate having a thickness of 11.8 mm is cut by 400 mm or more under conditions of not preheating at the time of gas cutting and a cutting speed of 500 mm/min.
  • the steel plate was reheated to a temperature of 910°C based on the center portion, maintained at 60 minutes after the center reached Ac3, quenched to 200°C at a cooling rate of 20°C to obtain a final product.
  • a final product was obtained in the same manner as in a case of Inventive Example 1, except that the product was air-cooled to ambient temperature, without being quenched after hot-rolling.
  • FIG. 2 shows the results of observing the structures of Inventive Example 1, Comparative Example 1, and Comparative Example 2 with a microscope.
  • FIG. 2A shows Inventive Example 1
  • FIG. 2B shows Comparative Example 1
  • FIG. 2C shows Comparative Example 2.
  • at least 95% of martensite was formed in Inventive Example 1, Comparative Example 1 and Comparative Example 2 (specifically, 96% of martensite was formed in Inventive Example 1, and 100% of martensite was formed in Comparative Examples 1 and 2, on the basis of an area) .
  • a slab having the composition shown in the following Table 1 was produced under the same conditions as in Inventive Example 1 of Example 1 to obtain wear-resistant steel.
  • the analysis results of the wear resistance obtained are shown in Table 2.
  • Comparative Example 7 of Table 2 shows the results of analysis in a case in which a slab having the same composition as that of Inventive Example 7 was prepared in the same manner as in Comparative Example 2 of Example 1.
  • cutting cracks in the steel plate tended to occur, when a cutting speed was relatively high and a thickness was relatively thick, under the condition of no preheating (without preheating) at the time of gas cutting. This results from the fact that the residual stress formed in the heat affected zone of the cut portion at the time of cutting is increased under the above conditions.
  • Comparative Example 3 in which amounts of carbon (C) and manganese (Mn) were lower than the values specified in the present invention, was found to have Brinell hardness of 410 on the surface layer portion which did not satisfy the level required in the present invention.
  • Comparative Example 4 was a case of not adding chromium (Cr) at all, which is advantageous in securing toughness, and also narrows a gap between an Ac1 and an Ac3 to increase the cutting crack resistance. As a result, impact toughness was found to be 67J which is very low.
  • Comparative Example 5 was a case in which carbon (C) was excessively added, the hardness was sufficient, but Charpy impact energy was to be only 22 J, thus the low-temperature toughness was thus found to be very poor.
  • Comparative Example 6 was a case in which an amount of carbon (C) was only 0.14%, and Brinell hardness was only 408, which did not satisfy the level required in the present invention.
  • Comparative Example 7 although the composition of the steel satisfied the conditions of the present invention, but when the steel was air-cooled after the hot-rolling, the prior austenite grain size was 38 ⁇ m, coarse crystal grains were formed, and the low-temperature toughness was lowered.
  • Comparative Example 4 and Comparative Example 6 also failed to satisfy the condition of the present invention, since the Ac3-Ac1 value thereof exceeded 100°C.
  • results of cutting cracks were occurred after one week performing cut operation under the given conditions.
  • cutting cracks occurred despite the narrow temperature range of Ac3-Acl, since Brinell hardness was excessively high, such that the cutting conditions used in this measuring method were severe conditions relative to hardness.

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)
EP16875937.1A 2015-12-15 2016-11-22 Hochharter abriebfester stahl mit hervorragender festigkeit und schneidrissbeständigkeit und verfahren zur herstellung davon Active EP3392364B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020150179009A KR101736621B1 (ko) 2015-12-15 2015-12-15 인성과 절단균열저항성이 우수한 고경도 내마모강 및 그 제조방법
PCT/KR2016/013491 WO2017104995A1 (ko) 2015-12-15 2016-11-22 인성과 절단균열저항성이 우수한 고경도 내마모강 및 그 제조방법

Publications (3)

Publication Number Publication Date
EP3392364A4 EP3392364A4 (de) 2018-10-24
EP3392364A1 true EP3392364A1 (de) 2018-10-24
EP3392364B1 EP3392364B1 (de) 2020-07-29

Family

ID=59052836

Family Applications (1)

Application Number Title Priority Date Filing Date
EP16875937.1A Active EP3392364B1 (de) 2015-12-15 2016-11-22 Hochharter abriebfester stahl mit hervorragender festigkeit und schneidrissbeständigkeit und verfahren zur herstellung davon

Country Status (6)

Country Link
US (1) US20190010571A1 (de)
EP (1) EP3392364B1 (de)
JP (1) JP6691967B2 (de)
KR (1) KR101736621B1 (de)
CN (1) CN108368589B (de)
WO (1) WO2017104995A1 (de)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102018122901A1 (de) 2018-09-18 2020-03-19 Voestalpine Stahl Gmbh Verfahren zur Herstellung ultrahochfester Stahlbleche und Stahlblech hierfür
JP7319518B2 (ja) * 2019-02-14 2023-08-02 日本製鉄株式会社 耐摩耗厚鋼板
CN112981066B (zh) * 2021-02-07 2022-09-30 松山湖材料实验室 高铬钢的热处理方法及热处理高铬钢

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS609824A (ja) * 1983-06-27 1985-01-18 Sumitomo Metal Ind Ltd 強靭鋼の製造方法
JP2004300474A (ja) * 2003-03-28 2004-10-28 Jfe Steel Kk 耐摩耗鋼およびその製造方法
JP4682822B2 (ja) 2004-11-30 2011-05-11 Ｊｆｅスチール株式会社 高強度熱延鋼板
JP4644105B2 (ja) * 2005-11-28 2011-03-02 新日本製鐵株式会社 ベイナイト鋼レールの熱処理方法
AU2009355404B2 (en) * 2009-11-17 2013-04-04 Nippon Steel Corporation High-toughness abrasion-resistant steel and manufacturing method therefor
JP5375916B2 (ja) * 2011-09-28 2013-12-25 Ｊｆｅスチール株式会社 平坦度に優れる耐磨耗鋼板の製造方法
CN102747280B (zh) * 2012-07-31 2014-10-01 宝山钢铁股份有限公司 一种高强度高韧性耐磨钢板及其制造方法
JPWO2014045552A1 (ja) * 2012-09-19 2016-08-18 Ｊｆｅスチール株式会社 低温靱性および耐腐食摩耗性に優れた耐摩耗鋼板
KR101439629B1 (ko) * 2012-10-15 2014-09-11 주식회사 포스코 내마모성이 우수한 내마모용 강재 및 그 제조방법
CN103805851B (zh) * 2012-11-15 2016-03-30 宝山钢铁股份有限公司 一种超高强度低成本热轧q&p钢及其生产方法
KR101439686B1 (ko) * 2012-12-26 2014-09-12 주식회사 포스코 내마모성이 우수한 내미끄럼마모용 강재 및 그 제조방법
JP6007847B2 (ja) * 2013-03-28 2016-10-12 Ｊｆｅスチール株式会社 低温靭性を有する耐磨耗厚鋼板およびその製造方法
CN103255341B (zh) * 2013-05-17 2015-07-22 宝山钢铁股份有限公司 一种高强度高韧性热轧耐磨钢及其制造方法
KR101322092B1 (ko) * 2013-08-01 2013-10-28 주식회사 포스코 용접성 및 저온인성이 우수한 내마모용 강판 및 그 제조방법
CN105940133B (zh) * 2014-01-28 2017-11-07 杰富意钢铁株式会社 耐磨损钢板及其制造方法
JP6217671B2 (ja) * 2014-03-31 2017-10-25 Ｊｆｅスチール株式会社 高温環境における耐摩耗性に優れた厚鋼板

Also Published As

Publication number Publication date
WO2017104995A1 (ko) 2017-06-22
KR101736621B1 (ko) 2017-05-30
JP2019504192A (ja) 2019-02-14
US20190010571A1 (en) 2019-01-10
EP3392364A4 (de) 2018-10-24
JP6691967B2 (ja) 2020-05-13
CN108368589A (zh) 2018-08-03
CN108368589B (zh) 2020-10-20
EP3392364B1 (de) 2020-07-29

Similar Documents

Publication Publication Date Title
EP3561130B1 (de) Hochharter verschleissfester stahl und verfahren zur herstellung davon
US10577671B2 (en) High-hardness hot-rolled steel product, and a method of manufacturing the same
KR101490567B1 (ko) 용접성이 우수한 고망간 내마모강 및 그 제조방법
KR102119959B1 (ko) 우수한 경도와 충격인성을 갖는 내마모강 및 그 제조방법
US11371125B2 (en) Wear-resistant steel having excellent hardness and impact toughness, and method for producing same
EP3561111B1 (de) Dickes stahlblech mit hervorragender kryogener schlagfestigkeit und herstellungsverfahren dafür
KR101899687B1 (ko) 고경도 내마모강 및 이의 제조방법
KR20210053526A (ko) 저온 충격인성이 우수한 고강도 강재 및 그 제조방법
CN112771194A (zh) 具有优异的硬度和冲击韧性的耐磨钢及其制造方法
EP3392364B1 (de) Hochharter abriebfester stahl mit hervorragender festigkeit und schneidrissbeständigkeit und verfahren zur herstellung davon
EP3395998B1 (de) Dicke stahlplatte mit hervorragender tieftemperaturzähigkeit und wasserstoffinduzierter rissbeständigkeit sowie verfahren zur herstellung davon
KR102164112B1 (ko) 연성 및 저온 인성이 우수한 고강도 강재 및 이의 제조방법
EP3733905A1 (de) Hochfestes baustahlmaterial mit hervorragenden ermüdungsrissausbreitungshemmenden eigenschaften und herstellungsverfahren dafür
US11473178B2 (en) Wear-resistant steel having excellent hardness and impact toughness, and method for producing same
KR101439686B1 (ko) 내마모성이 우수한 내미끄럼마모용 강재 및 그 제조방법
KR101439629B1 (ko) 내마모성이 우수한 내마모용 강재 및 그 제조방법
EP4063531A1 (de) Walzdraht für hochfeste feder, stahldraht und verfahren zur herstellung davon
KR101412365B1 (ko) 고강도 강판 및 그 제조 방법
JP7439241B2 (ja) 強度及び低温衝撃靭性に優れた鋼材及びその製造方法
KR101696097B1 (ko) 충격인성이 우수한 고강도 비조질 선재 및 이의 제조방법
KR101675677B1 (ko) 비열처리형 열연강판 및 그 제조 방법
EP4079918A1 (de) Abriebfester stahl mit hervorragender schneidrissbeständigkeit und verfahren zu seiner herstellung
KR20210062890A (ko) 고강도 열연 강판 및 그 제조방법
KR20210079482A (ko) 연성과 저온 충격인성이 우수한 강재 및 이의 제조방법

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20180605

A4 Supplementary search report drawn up and despatched

Effective date: 20180914

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20190820

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

RIC1 Information provided on ipc code assigned before grant

Ipc: C21D 8/02 20060101ALI20200129BHEP

Ipc: C21D 1/18 20060101ALI20200129BHEP

Ipc: C22C 38/28 20060101ALI20200129BHEP

Ipc: C22C 38/02 20060101ALI20200129BHEP

Ipc: C21D 9/46 20060101ALI20200129BHEP

Ipc: C21D 6/00 20060101ALI20200129BHEP

Ipc: C22C 38/26 20060101ALI20200129BHEP

Ipc: C22C 38/32 20060101ALI20200129BHEP

Ipc: C22C 38/38 20060101AFI20200129BHEP

INTG Intention to grant announced

Effective date: 20200219

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 1295871

Country of ref document: AT

Kind code of ref document: T

Effective date: 20200815

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602016041078

Country of ref document: DE

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20200729

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1295871

Country of ref document: AT

Kind code of ref document: T

Effective date: 20200729

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20201030

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20201029

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20201029

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20201130

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20201129

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602016041078

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

26N No opposition filed

Effective date: 20210430

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20201122

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20201122

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20201130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20201130

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20201130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20201122

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20201122

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20201129

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200729

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20201130

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 602016041078

Country of ref document: DE

Owner name: POSCO CO., LTD, POHANG-SI, KR

Free format text: FORMER OWNER: POSCO, POHANG-SI, GYEONGSANGBUK-DO, KR

Ref country code: DE

Ref legal event code: R081

Ref document number: 602016041078

Country of ref document: DE

Owner name: POSCO CO., LTD, POHANG- SI, KR

Free format text: FORMER OWNER: POSCO, POHANG-SI, GYEONGSANGBUK-DO, KR

Ref country code: DE

Ref legal event code: R081

Ref document number: 602016041078

Country of ref document: DE

Owner name: POSCO HOLDINGS INC., KR

Free format text: FORMER OWNER: POSCO, POHANG-SI, GYEONGSANGBUK-DO, KR

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 602016041078

Country of ref document: DE

Owner name: POSCO CO., LTD, POHANG-SI, KR

Free format text: FORMER OWNER: POSCO HOLDINGS INC., SEOUL, KR

Ref country code: DE

Ref legal event code: R081

Ref document number: 602016041078

Country of ref document: DE

Owner name: POSCO CO., LTD, POHANG- SI, KR

Free format text: FORMER OWNER: POSCO HOLDINGS INC., SEOUL, KR

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20231121

Year of fee payment: 8

Ref country code: FR

Payment date: 20231121

Year of fee payment: 8

Ref country code: DE

Payment date: 20231120

Year of fee payment: 8