[go: up one dir, main page]

US20160319415A1 - Hot dip galvanized steel sheet having excellent resistance to cracking due to liquid metal embrittlement - Google Patents

Hot dip galvanized steel sheet having excellent resistance to cracking due to liquid metal embrittlement Download PDF

Info

Publication number
US20160319415A1
US20160319415A1 US15/108,263 US201415108263A US2016319415A1 US 20160319415 A1 US20160319415 A1 US 20160319415A1 US 201415108263 A US201415108263 A US 201415108263A US 2016319415 A1 US2016319415 A1 US 2016319415A1
Authority
US
United States
Prior art keywords
steel sheet
hot
alloy layer
layer
liquid metal
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.)
Abandoned
Application number
US15/108,263
Other languages
English (en)
Inventor
Ju-Youn Lee
Kwang-Geun Chin
Sun-Ho Jeon
Jong-sang Kim
Myung-Soo Kim
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
Assigned to POSCO reassignment POSCO ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CHIN, KWANG-GEUN, JEON, SUN-HO, KIM, MYUNG-SOO, KIM, JONG-SANG, LEE, JU-YOUN
Publication of US20160319415A1 publication Critical patent/US20160319415A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06Zinc or cadmium or alloys based thereon
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C18/00Alloys based on zinc
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/001Ferrous alloys, e.g. steel alloys containing N
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/002Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/06Ferrous alloys, e.g. steel alloys containing aluminium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/08Ferrous alloys, e.g. steel alloys containing nickel
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/022Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • C23C2/0222Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating in a reactive atmosphere, e.g. oxidising or reducing atmosphere
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/022Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • C23C2/0224Two or more thermal pretreatments
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/024Pretreatment of the material to be coated, e.g. for coating on selected surface areas by cleaning or etching
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/026Deposition of sublayers, e.g. adhesion layers or pre-applied alloying elements or corrosion protection
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/34Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
    • C23C2/36Elongated material
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/34Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
    • C23C2/36Elongated material
    • C23C2/40Plates; Strips
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/02Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material

Definitions

  • the present disclosure relates to a hot-dip galvanized steel sheet having excellent resistance to cracking caused by liquid metal embrittlement.
  • body components of a vehicle are required to be lightweight while having stability. To this end, it is required to ensure high strength, ductility, and corrosion resistance in a steel sheet used for a component for a vehicle.
  • Patent Document 1 A representative technique therefor is disclosed in Patent Document 1.
  • the technique relates to a Twinning-Induced Plasticity (TWIP) type ultra high strength steel sheet including 0.15 wt % to 0.30 wt % of carbon (C), 0.01 wt % to 0.03 wt % of silicon (Si), 15 wt % to 25 wt % of manganese (Mn), 1.2 wt % to 3.0 wt % of aluminum (Al), 0.020 wt % or less of phosphorus (P), 0.001 wt % to 0.002 wt % of sulfur (S), and iron (Fe) as a residual component thereof, and inevitable impurities, and a microstructure of steel is formed of a structure in an austenite phase. Ultrahigh tensile and high elongation are ensured, whereby the TWIP type ultra high strength steel sheet complies with vehicle body weight requirements.
  • TWIP Twinning-Induced Plasticity
  • a hot-dip steel sheet has excellent corrosion resistance, whereby such hot-dip steel sheets have been widely used in building materials, structures, household appliances, vehicle bodies, and the like.
  • Types of hot-dip steel sheet which have been most recently widely used can be divided into either a hot-dip galvanized steel sheet (hereinafter referred to as ‘GI steel sheet’) or an alloyed hot-dip galvanized steel sheet (hereinafter referred to as ‘GA steel sheet’).
  • a GI steel sheet is a steel sheet plated with molten zinc.
  • the GI steel sheet can be easily plated, and has excellent corrosion resistance.
  • the GI steel sheet has been widely used in vehicle bodies.
  • a general GI steel sheet is a steel sheet in which a plating layer is formed as the GI steel sheet is submerged in a zinc plating bath to which 0.16 wt % to 0.25 wt % of Al has been added.
  • the plating layer is composed mostly of zinc, but an alloying suppression layer capable of suppressing the alloying of iron and zinc is provided in a thickness of 1 ⁇ m or less at an interface between a base steel and a zinc plating layer.
  • the alloying suppression layer is generally composed of Fe 2 Al 5-x Zn x .
  • spot-welding is generally performed.
  • an alloying suppression layer formed in the GI steel sheet is melted by welding heat, thereby generating liquid zinc.
  • a temperature of a welded portion is increased to about 1500° C. or more within about 1 second, whereby a base steel and a plating layer are melted and welded.
  • a temperature of a plating layer is increased to 600° C. to 800° C.
  • liquid metal embrittlement (hereinafter referred to as ‘LME’).
  • the TWIP steel In the case of a TWIP steel in which an austenite fraction is greater or the like, the TWIP steel has a higher resistance value than that of other types of steel, whereby the TWIP steel will be in a state of high temperature. In addition, as a grain boundary is expanded by a high thermal expansion coefficient, a liquid metal embrittlement problem may occur severely. In addition, in the case of TWIP steel, the TWIP steel has a higher thermal expansion coefficient than that of other types of steel such as a ferritic steel sheet and the like, whereby thermal stress may be caused. As a result, without external tensile stress, the thermal stress is applied to a welded portion, whereby the possibility of the occurrence of liquid metal embrittlement may be very high.
  • FIG. 1 is a view illustrating GI TWIP steel in which an LME crack is present in a welded portion.
  • the LME crack causes fracturing of a steel sheet, whereby it may be difficult to use GI TWIP steel as a component for a vehicle and the like.
  • Patent document 1 Korea Patent Laid-Open Publication No. 2007-0018416
  • An aspect of the present disclosure is to provide a hot-dip galvanized steel sheet having excellent resistance to cracking caused by liquid metal embrittlement.
  • a hot-dip galvanized steel sheet having excellent resistance to cracking caused by liquid metal embrittlement may include: a base steel sheet having a microstructure in which an austenite fraction is 90 area % or more; and a hot-dip galvanizing layer formed on the base steel sheet.
  • the hot-dip galvanizing layer may include: an Fe—Zn alloy layer; and a Zn layer formed on the Fe—Zn alloy layer.
  • the Fe—Zn alloy layer may have a thickness of [(3.4 ⁇ t)/6] ⁇ m or more, where t is a thickness of the hot-dip galvanizing layer.
  • a hot-dip galvanized steel sheet in which plating layer delamination which may easily occur under vehicle welding and molding conditions according to the related art may be prevented, and the occurrence of cracking caused by liquid metal embrittlement may be suppressed.
  • FIG. 1 is a view illustrating GI TWIP steel in which an LME crack occurs in a welded portion.
  • FIG. 2A is a schematic view illustrating a cross section of existing GI TWIP steel
  • FIG. 2B is a schematic view illustrating a cross section of a hot-dip galvanized steel sheet according to an exemplary embodiment in the present disclosure.
  • FIG. 3 is a view of a cross section of a welded portion of inventive example 1 according to an exemplary embodiment in the present disclosure.
  • FIG. 4 is a view of a cross section of a welded portion of comparative example 1 outside of a range according to an exemplary embodiment in the present disclosure.
  • the inventors have conducted research into effectively suppressing the occurrence of cracking caused by liquid metal embrittlement (LME) when the above mentioned GI TIWP steel is manufactured.
  • LME liquid metal embrittlement
  • the present disclosure is proposed under the discovery that occurrence of cracking caused by LME may be prevented by suppressing the formation of a surface oxide used to suppress the diffusion of iron (Fe) and an Fe—Al or Fe—Al—Zn alloy layer, and by forming an Fe—Zn alloy layer having a sufficient thickness.
  • FIG. 2A is a schematic view illustrating a cross section of existing GI TWIP steel
  • FIG. 2B is a schematic view illustrating a cross section of a hot-dip galvanized steel sheet according to an exemplary embodiment in the present disclosure.
  • FIG. 2 schematically illustrates an exemplary embodiment in the present disclosure to illustrate the present disclosure, but does not limit the scope of the present disclosure.
  • an alloying suppression layer Fe—Al or Fe—Al—Zn alloy layer 2 is formed on a base steel sheet 1 , and a Zn layer 3 is formed on the alloying suppression layer 2 .
  • a surface oxide 4 such as MnO or the like exists between the base steel sheet 1 and the Zn layer 3 .
  • GI TWIP steel including a plating layer having such a structure when spot-welding, liquid zinc is generated due to the alloying suppression layer 2 , thereby causing LME cracking.
  • a hot-dip galvanized steel sheet includes a base steel sheet 10 , and a hot-dip galvanizing layer 20 formed on the base steel sheet.
  • the hot-dip galvanizing layer 20 has a structure in which an Fe—Zn alloy layer 21 and a Zn layer 22 are sequentially formed.
  • the hot-dip galvanizing layer 20 according to an exemplary embodiment in the present disclosure formed on the base steel sheet 10 may preferably have a structure in which an Fe—Zn alloy layer 21 and a Zn layer 22 are sequentially formed.
  • a hot-dip galvanized steel sheet according to an exemplary embodiment in the present disclosure may preferably have a microstructure in which an austenite fraction is 90 area % or more.
  • a base steel sheet used in a hot-dip galvanized steel sheet may include, by wt %, carbon (C): 0.10% to 0.30%, manganese (Mn): 10% to 30%, silicon (Si): 0.01% to 0.03%, titanium (Ti): 0.05% to 0.2%, manganese (Mn): 10% to 30%, aluminum (Al): 0.5% to 3.0%, nickel (Ni): 0.001% to 10%, chromium (Cr): 0.001% to 10%, nitrogen (N): 0.001% to 0.05%, phosphorus (P): 0.020% or less, sulfur (S): 0.001% to 0.005%, and iron (Fe) as a residual component thereof, and inevitable impurities.
  • the Fe—Zn alloy layer 21 is formed to have a sufficient thickness.
  • the Fe—Zn alloy layer 21 allows the formation of liquid zinc to be decreased, thereby suppressing occurrence of cracking caused by LME.
  • Zn preferentially reacts with Fe, the transformation of Zn into liquid zinc due to a heat effect caused by welding may be suppressed.
  • the Fe—Zn alloy layer 21 is formed to a sufficient thickness in advance, thereby improving the above-described effect.
  • a thickness of the Fe—Zn alloy layer be [(3.4 ⁇ t)/6] ⁇ m or more.
  • a thickness of the Fe—Zn alloy layer is less than [(3.4 ⁇ t)/6] ⁇ m, an effect of suppressing occurrence of cracking caused by LME may not be sufficiently obtained.
  • the above described t refers to a thickness of the hot-dip galvanizing layer. According to an exemplary embodiment in the present disclosure, as a thickness of the Fe—Zn alloy layer is increased, a preferable effect may be obtained.
  • an upper limit of the Fe—Zn alloy layer thickness is not particularly limited.
  • the Fe—Zn alloy layer 21 includes Fe of 3 wt % to 15 wt %.
  • Fe contents inside the Fe—Zn alloy layer are less than 3 wt %, in an amount the same as that of an existing GI steel sheet, there may be a disadvantage that cracking caused by LME occurs.
  • Fe contents inside the Fe—Zn alloy layer are more than 15 wt %, a problem of decreasing workability may occur.
  • Zn may remain as a Zn layer on the Fe—Zn alloy layer 21 as Zn does not react to Fe.
  • an Fe—Al or Fe—Al—Zn alloy layer 23 formed in a lower part of the hot-dip galvanizing layer 20 in other words, between a base steel sheet 10 and an Fe—Zn alloy layer 21 as possible.
  • the Fe—Al or Fe—Al—Zn alloy layer 23 may cause cracking caused by LME by forming liquid zinc when welding.
  • a thickness of the Fe—Al or Fe—Al—Zn alloy layer 23 is formed to be as thin as possible.
  • component contents of the Fe—Al and Fe—Al—Zn alloy layer are not particularly limited.
  • the Fe—Al alloy layer may be Fe 2 Al 5
  • the Fe—Al—Zn alloy layer may be Fe 2 Al 5 Zn x .
  • the alloy layer 23 includes 0.3 wt % or less of Al.
  • Al contents contained in the alloy layer 23 exceed 0.3 wt %, diffusion of Fe is suppressed.
  • an Fe—Ni alloy layer 30 is further included directly below a surface of the base steel sheet. More particularly, the Fe—Ni alloy layer 30 may ensure excellent plating adhesion as MnO or the like exists as an internal oxide 40 by suppressing a surface oxide such as MnO or the like from being formed, as an oxidizing element such as Mn or the like is enriched on a surface of the Fe—Ni alloy layer 30 , in the manner of TWIP steel. To ensure the above effect, the Fe—Ni alloy layer may be formed by a Ni coating layer having an adhesion amount of 300 mg/m 2 to 1000 mg/m 2 , and a thickness of the Fe—Ni alloy layer may be different according to manufacturing conditions.
  • a thickness of the Fe—Ni alloy layer may have a range of 0.05 ⁇ m to 5 ⁇ m.
  • the Fe—Ni alloy layer is formed to have a thickness less than 0.05 ⁇ m, zinc wettability is decreased, thereby being non-plated or decreasing plating adhesion.
  • a thickness of the Fe—Ni alloy layer exceeds 5 ⁇ m, a problem that an amount of Fe diffused into a plating layer from a base steel sheet is reduced may occur, and manufacturing costs may be sharply increased.
  • one or more type selected from a group consisting of an Fe—X alloy layer, an Fe—Al—X alloy layer, an Fe—Al—Zn—X alloy layer, and an Fe—Zn—X alloy layer may be additionally included between the base steel sheet and the hot-dip galvanizing layer.
  • the alloy layer As the alloy layer is formed, plating adhesion and excellent resistance to occurrence of cracking caused by LME may be ensured.
  • the above-described X for example, is a material which may have cations inside an electroplating solution, and the X may be one of Ni and Cr.
  • the hot-dip galvanized steel sheet according to an exemplary embodiment in the present disclosure provided as described above may ensure excellent resistance to cracking caused by LME, and may ensure an excellent level of plating adhesion, a physical property typically required in a hot-dip galvanized steel sheet.
  • the hot-dip galvanized steel sheet according to an exemplary embodiment in the present disclosure may be manufactured by various methods.
  • the base steel sheet is heated to a temperature of 700° C. to 900° C. in a reducing atmosphere furnace charged with a H 2 —N 2 mixed gas, and the heated base steel sheet is cooled.
  • the base steel sheet is submerged in a molten zinc plating bath at 440° C. to 460° C. including 0.13 wt % or less of Al.
  • the hot-dip galvanized steel sheet may be manufactured by using the above-mentioned method.
  • the hot-dip galvanized steel sheet proposed according to an exemplary embodiment in the present disclosure may be manufactured.
  • abase steel sheet having a microstructure in which an austenite fraction is 90 area % or more is prepared.
  • the base steel sheet as TWIP steel, has a high austenite fraction.
  • the base steel sheet includes a large amount of Mn, Al, Ni, and the like such as an oxidizing element.
  • a surface of the base steel sheet is required to be cleaned beforehand. For example, to remove foreign substances or an oxide film or the like from a surface thereof, it may be preferable to perform a pickling or cleaning process. When the pickling or cleaning process is not performed, a coating layer or a plating layer is not uniform, and a plating appearance or adhesion may be decreased.
  • a Ni coating layer is formed on the prepared base steel sheet as described above. Formation of the Ni coating layer may be performed by electro-plating. Thus, a coating layer having a uniform thickness may be formed. On the other hand, the Ni coating layer preferably has an adhesion of 300 mg/m 2 to 1000 mg/m 2 . When an adhesion of the Ni coating layer is less than 300 mg/m 2 , an Fe—Ni alloy layer having a sufficient thickness is not formed.
  • a surface enrichment amount of Mn is not sufficiently suppressed, and zinc wettability is also decreased, thereby causing a non-plating phenomenon or decreasing plating adhesion.
  • an adhesion amount of the Ni coating layer exceeds 1000 mg/m 2 , an amount of Fe diffused into a plating layer from a base steel sheet is decreased by forming an Fe—Ni alloy layer in which Ni contents are high.
  • an Fe—Zn alloy layer having a sufficient thickness may not be obtained, and manufacturing costs may be sharply increased.
  • the base steel sheet having the Ni coating layer is heated to a temperature of 700° C. to 900° C. in a reducing atmosphere furnace charged with a H 2 —N 2 mixed gas.
  • Ni in the Ni coating layer may penetrate into an interior of the base steel sheet, thereby forming an Fe—Ni alloy layer.
  • the heating temperature is lower than 700° C., a steel sheet structure is not transformed into a structure formed in an austenite phase after cold-rolling the steel sheet structure.
  • the heating temperature exceeds 900° C., chances that deformation and fractures will occur in a steel sheet are increased.
  • the base steel sheet After heating, it may be preferable that the base steel sheet is maintained in the heating temperature range for 20 or more seconds. When the retention time is less than 20 seconds, an Fe—Ni alloy layer having a sufficient thickness is not formed. Thus, a surface enrichment amount of Mn is not sufficiently suppressed.
  • the heated base steel sheet is cooled to a temperature between 400° C. to 500° C. at a cooling rate of 5° C./s or more.
  • the cooling rate is less than 5° C./s, it may be difficult to obtain austenite of 90 area % or more.
  • a plating bath insertion temperature of the cooled base steel sheet is controlled to have a range of (molten zinc plating bath ⁇ 40° C.) to (molten zinc plating bath+10° C.).
  • the plating bath insertion temperature is lower than (molten zinc plating bath ⁇ 40° C.)
  • Fe contained in a base steel sheet is less eluted, thereby suppressing formation of a structure in an Fe—Zn alloy phase.
  • the plating bath insertion temperature exceeds (molten zinc plating bath+10° C.), an Fe—Al or Fe—Al—Zn alloy layer is thickly formed, thereby interfering in diffusion of Fe.
  • controlling a plating bath insertion temperature of the base steel sheet may be performed by cooling the base steel sheet when the cooling stop temperature is higher than the plating bath insertion temperature, maintaining the base steel sheet at temperature when the cooling stop temperature is the same as the plating bath insertion temperature, and heating the base steel sheet when the cooling stop temperature is lower than the plating bath insertion temperature.
  • the base steel sheet controlled in a range of the plating bath insertion temperature is submerged into a molten zinc plating bath at 440° C. to 460° C. including 0.13 wt % or less of Al, whereby a plating solution is applied to a surface of the base steel sheet.
  • contents of Al of the molten zinc plating bath exceed 0.13 wt %, diffusion of Fe is suppressed, whereby it may be difficult to obtain an Fe—Zn alloy layer having a sufficient thickness.
  • a temperature of the molten zinc plating bath is lower than 440° C., it may be difficult to ensure fluidity of a plating solution, whereby plating may not be performed smoothly.
  • a temperature of the molten zinc plating bath exceeds 460° C., a problem that a plating solution is volatilized or the like, may occur.
  • the base steel sheet to which the plating solution is applied is slowly cooled at a slow cooling rate of 4° C./s to 20° C./s, thereby forming a hot-dip galvanizing layer.
  • a slow cooling rate of 4° C./s to 20° C./s
  • unsolidified zinc may be smeared on equipment such as a roll, thereby causing secondary product defects.
  • the slow cooling rate exceeds 20° C./s, there may be a disadvantage that the Fe—Zn alloy layer does not grow enough to have a sufficient thickness.
  • an Fe—Ni alloy layer is formed directly below a surface of the base steel sheet, and Fe contained inside the base steel sheet is diffused to a plating layer simultaneously.
  • a hot-dip galvanizing layer having a structure required according to an exemplary embodiment in the present disclosure may be formed on the base steel sheet.
  • a Ni coating layer was formed on the base steel sheet through electro-plating and provided as an adhesion amount in table 1 (comparative examples 2 to 4 were not carried out).
  • the base steel sheet was heated under the conditions of table 1 in a reducing atmosphere furnace charged with a 5% H 2 —N 2 mixed gas, the base steel sheet was cooled to 400° C.
  • the base steel sheet was submerged in a molten zinc plating bath at 460° C., and then a plating solution was applied to the base steel sheet.
  • the hot-dip galvanized steel sheet was spot-welded at a welding current of 5.8 kA, a size of individual cracks caused by LME was measured, and results thereof were shown in table 1.
  • the plating adhesion evaluation was conducted by checking whether a plating material was smeared on tape after bending a hot-dip galvanized steel sheet through 180°. When the plating material was smeared on the tape, it was shown as separation. When plating material was not smeared on the tape, it was shown as non-separation.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Coating With Molten Metal (AREA)
US15/108,263 2013-12-25 2014-12-24 Hot dip galvanized steel sheet having excellent resistance to cracking due to liquid metal embrittlement Abandoned US20160319415A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
KR10-2013-0163336 2013-12-25
KR1020130163336A KR101568543B1 (ko) 2013-12-25 2013-12-25 액체금속취화에 의한 크랙 저항성이 우수한 용융아연도금강판
PCT/KR2014/012824 WO2015099455A1 (fr) 2013-12-25 2014-12-24 Tôle d'acier plaquée par du zinc fondu présentant une excellente résistance aux fissures dues à un bromure métallique liquide

Publications (1)

Publication Number Publication Date
US20160319415A1 true US20160319415A1 (en) 2016-11-03

Family

ID=53479219

Family Applications (1)

Application Number Title Priority Date Filing Date
US15/108,263 Abandoned US20160319415A1 (en) 2013-12-25 2014-12-24 Hot dip galvanized steel sheet having excellent resistance to cracking due to liquid metal embrittlement

Country Status (6)

Country Link
US (1) US20160319415A1 (fr)
EP (1) EP3088557B1 (fr)
JP (1) JP6317453B2 (fr)
KR (1) KR101568543B1 (fr)
CN (1) CN105849304A (fr)
WO (1) WO2015099455A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018203126A1 (fr) 2017-05-05 2018-11-08 Arcelormittal Procédé de fabrication d'une tôle d'acier recuite après galvanisation résistant à la fragilisation par métal liquide
EP3758888A4 (fr) * 2018-03-01 2021-12-22 Nucor Corporation Revêtement d'alliage à base de zinc pour acier et procédés
CN114369782A (zh) * 2021-12-10 2022-04-19 首钢集团有限公司 一种无微观裂纹的热镀锌镀层钢板及其制备方法
WO2022107580A1 (fr) * 2020-11-17 2022-05-27 日本製鉄株式会社 Feuille d'acier plaquée pour utilisation de soudage par points, élément de jonction, élément automobile et procédé de fabrication d'élément de jonction
US12031215B2 (en) 2020-01-29 2024-07-09 Nucor Corporation Zinc alloy coating layer of press-hardenable steel
US12359294B2 (en) 2018-03-01 2025-07-15 Nucor Corporation Zinc alloy coated press-hardenable steels and method of manufacturing the same
US12378626B2 (en) 2020-02-13 2025-08-05 Jfe Steel Corporation High-strength steel sheet and method for manufacturing the same

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018115948A1 (fr) * 2016-12-21 2018-06-28 Arcelormittal Procédé de fabrication d'une tôle d'acier revêtue
WO2018115946A1 (fr) * 2016-12-21 2018-06-28 Arcelormittal Procédé de fabrication d'une tôle d'acier revêtue
WO2018115947A1 (fr) * 2016-12-21 2018-06-28 Arcelormittal Procédé de fabrication d'une tôle d'acier revêtue
EP3701058B1 (fr) * 2017-10-24 2024-05-15 ArcelorMittal Procédé permettant la fabrication d'une tôle d'âcier recuite par galvanisation
KR102206929B1 (ko) 2017-10-24 2021-01-25 아르셀러미탈 코팅된 강 시트의 제조 방법
US11466354B2 (en) 2017-10-24 2022-10-11 Arcelormittal Method for the manufacture of a coated steel sheet
BR112020006128A2 (pt) * 2017-10-24 2020-09-24 Arcelormittal método para a fabricação de uma chapa de aço revestida, chapa de aço, junta soldada e uso de uma chapa de aço revestida
WO2019097440A1 (fr) 2017-11-17 2019-05-23 Arcelormittal Procédé pour la fabrication d'une tôle d'acier revêtue de zinc résistant à la fragilisation par métal liquide
CN108842122B (zh) * 2018-08-06 2021-06-15 首钢集团有限公司 一种热浸镀镀层钢板及其制造方法
KR102200155B1 (ko) * 2019-12-06 2021-01-07 주식회사 포스코 용접구조물의 제조방법 및 이에 의해 제조된 용접구조물
US11441039B2 (en) * 2020-12-18 2022-09-13 GM Global Technology Operations LLC High temperature coatings to mitigate weld cracking in resistance welding
CN118139712A (zh) * 2021-11-02 2024-06-04 杰富意钢铁株式会社 电阻点焊构件及其电阻点焊方法
US20250075291A1 (en) * 2022-01-06 2025-03-06 Nippon Steel Corporation Welded joint
WO2023132241A1 (fr) * 2022-01-06 2023-07-13 日本製鉄株式会社 Joint soudé
KR102877272B1 (ko) * 2023-03-15 2025-10-29 서울과학기술대학교 산학협력단 침염현상을 이용한 액체금속 박막 제조방법
CN119242989B (zh) * 2024-09-23 2025-06-06 首钢集团有限公司 镀层钢及其制备方法、钢制件及其制备方法和应用

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2631319A (en) * 1947-12-09 1953-03-17 Gotsfeld Morris Bath brush having oppositely extending detachable handle
JP2004124187A (ja) * 2002-10-03 2004-04-22 Sumitomo Metal Ind Ltd 密着性・溶接性に優れた高強度溶融亜鉛めっき鋼板
WO2006082104A1 (fr) * 2005-02-02 2006-08-10 Corus Staal Bv Acier austenitique a tenue et aptitude au formage elevees, procede de production dudit acier et son utilisation
KR20120004248A (ko) * 2010-07-06 2012-01-12 주식회사 영우디에스피 오엘이디 패널의 에이징 장치

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0559513A (ja) * 1991-09-02 1993-03-09 Sumitomo Metal Ind Ltd 耐パウダリング性めつき鋼板の製造法
JP4329639B2 (ja) 2004-07-23 2009-09-09 住友金属工業株式会社 耐液体金属脆性に優れた熱処理用鋼板
KR20070018416A (ko) * 2005-08-10 2007-02-14 현대자동차주식회사 자동차 차체부품용 twip형 초고강도 강판 및 그제조방법
ES2455222T5 (es) * 2010-07-02 2018-03-05 Thyssenkrupp Steel Europe Ag Acero de resistencia superior, conformable en frío y producto plano de acero compuesto de un acero de este tipo
KR20120041544A (ko) * 2010-10-21 2012-05-02 주식회사 포스코 도금성, 도금밀착성 및 스폿용접성이 우수한 용융아연도금강판 및 그 제조방법
KR101242859B1 (ko) * 2010-11-05 2013-03-12 주식회사 포스코 도금성 및 도금밀착성이 우수한 고망간 용융아연도금강판 및 그 제조방법
JP5817479B2 (ja) * 2011-03-10 2015-11-18 Jfeスチール株式会社 熱間プレス部材の製造方法
KR101359183B1 (ko) * 2011-06-28 2014-02-06 주식회사 포스코 액상 금속 취화가 억제된 열간 프레스 성형용 도금강판
KR20130026133A (ko) * 2011-09-05 2013-03-13 주식회사 포스코 도금성 및 표면외관이 우수한 고망간강 용융아연도금강판 및 그 제조방법

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2631319A (en) * 1947-12-09 1953-03-17 Gotsfeld Morris Bath brush having oppositely extending detachable handle
JP2004124187A (ja) * 2002-10-03 2004-04-22 Sumitomo Metal Ind Ltd 密着性・溶接性に優れた高強度溶融亜鉛めっき鋼板
WO2006082104A1 (fr) * 2005-02-02 2006-08-10 Corus Staal Bv Acier austenitique a tenue et aptitude au formage elevees, procede de production dudit acier et son utilisation
KR20120004248A (ko) * 2010-07-06 2012-01-12 주식회사 영우디에스피 오엘이디 패널의 에이징 장치

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Machine Translation, Ishigaki et al., JP 2004-124187, 04-2004. *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018203126A1 (fr) 2017-05-05 2018-11-08 Arcelormittal Procédé de fabrication d'une tôle d'acier recuite après galvanisation résistant à la fragilisation par métal liquide
WO2018203097A1 (fr) 2017-05-05 2018-11-08 Arcelormittal Procédé de fabrication d'une tôle d'acier recuite après galvanisation résistant à la fragilisation par métal liquide
US11654653B2 (en) 2017-05-05 2023-05-23 Arcelormittal Method for the manufacturing of liquid metal embrittlement resistant galvannealed steel sheet
US12134245B2 (en) 2017-05-05 2024-11-05 Arcelormittal Method for the manufacturing of liquid metal embrittlement resistant galvannealed steel sheet
EP3758888A4 (fr) * 2018-03-01 2021-12-22 Nucor Corporation Revêtement d'alliage à base de zinc pour acier et procédés
US12359294B2 (en) 2018-03-01 2025-07-15 Nucor Corporation Zinc alloy coated press-hardenable steels and method of manufacturing the same
US12031215B2 (en) 2020-01-29 2024-07-09 Nucor Corporation Zinc alloy coating layer of press-hardenable steel
US12378626B2 (en) 2020-02-13 2025-08-05 Jfe Steel Corporation High-strength steel sheet and method for manufacturing the same
WO2022107580A1 (fr) * 2020-11-17 2022-05-27 日本製鉄株式会社 Feuille d'acier plaquée pour utilisation de soudage par points, élément de jonction, élément automobile et procédé de fabrication d'élément de jonction
CN114369782A (zh) * 2021-12-10 2022-04-19 首钢集团有限公司 一种无微观裂纹的热镀锌镀层钢板及其制备方法

Also Published As

Publication number Publication date
CN105849304A (zh) 2016-08-10
EP3088557A4 (fr) 2017-03-22
EP3088557B1 (fr) 2018-07-11
WO2015099455A8 (fr) 2015-08-20
KR101568543B1 (ko) 2015-11-11
EP3088557A1 (fr) 2016-11-02
JP2017510702A (ja) 2017-04-13
WO2015099455A1 (fr) 2015-07-02
JP6317453B2 (ja) 2018-04-25
KR20150075291A (ko) 2015-07-03

Similar Documents

Publication Publication Date Title
EP3088557B1 (fr) Tôle d'acier galvaniser à chaud ayant une excellent résistance à la fissuration due à la fragilisation par métal liquide
US10253386B2 (en) Steel sheet for hot press-forming, method for manufacturing the same, and method for producing hot press-formed parts using the same
US9314997B2 (en) Plated steel sheet having plated layer with excellent stability for hot press molding
US11408047B2 (en) Alloyed hot-dip galvanized steel sheet and alloyed hot-dip galvanized steel sheet production method
US11814695B2 (en) Method for manufacturing high-strength galvanized steel sheet and high-strength galvanized steel sheet
CN107109582B (zh) 表面质量、镀覆粘附性及成型性优异的高强度热浸镀锌钢板及其制造方法
KR101692129B1 (ko) 고강도 용융 아연 도금 강판의 제조 방법 및 고강도 용융 아연 도금 강판
KR101657866B1 (ko) 고강도 용융 아연 도금 강판 및 그 제조 방법
JP4837604B2 (ja) 合金化溶融亜鉛めっき鋼板
EP3900866A1 (fr) Élément de soudage par points
KR102065287B1 (ko) 도금성 및 용접성이 우수한 오스테나이트계 용융 알루미늄 도금강판 및 그 제조방법
WO2014136412A1 (fr) Tôle d'acier hautement résistante ainsi que procédé de fabrication de celle-ci, et tôle d'acier galvanisée à chaud hautement résistante ainsi que procédé de fabrication de celle-ci
KR101647223B1 (ko) 표면품질 및 도금밀착성이 우수한 고강도 용융아연도금강판 및 그 제조방법
EP4215294A1 (fr) Élément formé à chaud à la presse, tôle d'acier pour formage à chaud à la presse et leurs procédés de production
CN110662854A (zh) 液态金属脆化龟裂抵抗性优异的钢板及其制造方法
US20240367254A1 (en) Resistance spot welded member and resistance spot welding method therefor
CN110088349B (zh) 牺牲腐蚀保护性及镀覆性优异的高锰热浸镀铝钢板及其制造方法
KR101528010B1 (ko) 도금성이 우수한 고망간강 용융아연도금강판 및 이의 제조방법
KR101978014B1 (ko) 고강도 강판 및 고강도 용융 아연 도금 강판 그리고 그것들의 제조 방법
KR101630960B1 (ko) 가공성 및 점용접성이 우수한 합금화 용융아연도금강판 및 그 제조방법
JP4940813B2 (ja) TS×Elの値が21000MPa・%以上である溶融亜鉛めっき鋼板の製造方法
KR101736640B1 (ko) 도금성 및 점용접성이 우수한 아연계 도금강판 및 그 제조방법
US20240399439A1 (en) Hot pressed member
JP4975406B2 (ja) 高張力合金化溶融亜鉛めっき鋼板およびその製造方法
KR101879081B1 (ko) 희생방식성 및 도금성이 우수한 고망간 용융 알루미늄 도금강판 및 그 제조방법

Legal Events

Date Code Title Description
AS Assignment

Owner name: POSCO, KOREA, REPUBLIC OF

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LEE, JU-YOUN;CHIN, KWANG-GEUN;JEON, SUN-HO;AND OTHERS;SIGNING DATES FROM 20160524 TO 20160623;REEL/FRAME:039009/0078

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION