EP3543366B1 - Steel sheet, steel pipe for line pipe, and production method therefor - Google Patents

Steel sheet, steel pipe for line pipe, and production method therefor Download PDF

Info

Publication number
EP3543366B1
EP3543366B1 EP17871656.9A EP17871656A EP3543366B1 EP 3543366 B1 EP3543366 B1 EP 3543366B1 EP 17871656 A EP17871656 A EP 17871656A EP 3543366 B1 EP3543366 B1 EP 3543366B1
Authority
EP
European Patent Office
Prior art keywords
mass
less
steel plate
bubbles
slab
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP17871656.9A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP3543366A1 (en
EP3543366A4 (en
Inventor
Kiichiro TASHIRO
Motoki KAKIZAKI
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.)
Kobe Steel Ltd
Original Assignee
Kobe Steel 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 Kobe Steel Ltd filed Critical Kobe Steel Ltd
Priority claimed from PCT/JP2017/039785 external-priority patent/WO2018092605A1/ja
Publication of EP3543366A1 publication Critical patent/EP3543366A1/en
Publication of EP3543366A4 publication Critical patent/EP3543366A4/en
Application granted granted Critical
Publication of EP3543366B1 publication Critical patent/EP3543366B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10—Supplying or treating molten metal
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific 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
    • 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
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—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
    • 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
    • C21D9/0081—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for slabs; for billets
    • 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
    • C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • 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
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron

Definitions

  • the present disclosure relates to a steel plate, a steel pipe for a line pipe, and a production method therefor.
  • HIC Hydrogen induced cracking
  • the surface layer part in the thickness direction of the steel plate is more likely to cause HIC than the center in the thickness direction of the steel plate, and thus the surface layer part is required to improve its HIC resistance.
  • Patent Document 1 discloses that the HIC resistance is improved by controlling the amount of Ar gas blown into a molten steel to a predetermined level or less to thereby reduce an amount of Ar-gas uncompressed bubbles in the steel material which would form accumulation and segregation zones of MnS, Ca-Al based, and Ca-based inclusion clusters and Ti-based and Nb-based inclusions, causing the HIC.
  • Patent Document 2 discloses that the HIC resistance is improved by controlling a Ca concentration in a slab within a predetermined range during manufacture of the slab and also by controlling the contents of Ca, S and O as well as the content of Ar gas in a steel material within respective predetermined ranges.
  • Patent Document 1 does not consider uncompressed bubbles in a steel material of the final product, even though it has considered the decrease in the number of bubbles in the slab. Consequently, defects induced by uncompressed bubbles remaining in the steel material cannot be controlled, and HIC due to the uncompressed bubbles cannot be suppressed.
  • Patent Document 2 does not consider the size of bubbles and the presence of uncompressed bubbles in a steel material, even though it has considered the decrease in the content of Ar-gas bubbles in the steel material. Thus, even in the presence of a small amount of coarse Ar bubbles, this method cannot sufficiently suppress the HIC.
  • An embodiment of the present invention has been made in view of the foregoing circumstance, and thus it is a main object of the embodiment of the present invention to provide a steel plate and a steel pipe for a line pipe that have excellent hydrogen induced cracking resistance.
  • the embodiments of the present invention provide a steel plate and a steel pipe for a line pipe that have excellent hydrogen induced cracking resistance, as well as a method for producing the steel plate.
  • the present inventors have conducted intensive studies about the correlation between the CLR (Crack Length Ratio, a proportion [%] of the total length of cracks to the width of a test piece, a crack length ratio) of the surface layer part measured by a HIC test and internal defects in the steel plate measured by an ultrasonic flaw detection test.
  • CLR Chip Length Ratio, a proportion [%] of the total length of cracks to the width of a test piece, a crack length ratio
  • the excellent HIC resistance can be achieved by controlling the chemical composition of the steel plate within a predetermined range such that the contents of Ca, S and O satisfy predetermined relational expressions, and also by controlling internal defects such that the area ratio of a part that has a defect echo height of 20% or more is 0.05% or less.
  • a steel plate according to an embodiment of the present invention contains, C: 0.02 to 0.15% by mass, Si: 0.02 to 0.50% by mass, Mn: 0.6 to 2.0% by mass, P: more than 0% by mass and 0.030% by mass or less, S: more than 0% by mass and 0.003% by mass or less, Al: 0.010 to 0.080% by mass, Ca: 0.0003 to 0.0060% by mass, N: 0.001 to 0.010% by mass, and O: more than 0% by mass and 0.0045% by mass or less, with the balance being iron and inevitable impurities, wherein the steel plate satisfies the following formulae (1) and (2): 3.0 ⁇ Ca / S Ca ⁇ 1.25 ⁇ S / O ⁇ 1.80 where [Ca], [S] and [O] are contents (% by mass) of Ca, S and O respectively.
  • the steel plate with excellent hydrogen induced cracking resistance can be obtained.
  • the C content is an element essential to ensure the strengths of a base material and a welded part.
  • the C content needs to be 0.02% by mass or more.
  • the C content is preferably 0.03% by mass or more, and more preferably 0.04% by mass or more.
  • an extremely high C content degrades the HAZ toughness and a weldability of the steel.
  • an excessive C content is more likely to form NbC or island-shaped martensite, which becomes a starting point of HIC or a fracture propagation route.
  • the C content needs to be 0.15% by mass or less.
  • the C content is preferably 0.12% by mass or less, and more preferably 0.10% by mass or less.
  • the Si is an element that has a deoxidation function and is effective in improving the strengths of a base material and a welded part.
  • the Si content is set at 0.02% by mass or more.
  • the Si content is preferably 0.05% by mass or more, and more preferably 0.15% by mass or more.
  • an extremely high Si content degrades the weldability and toughness of the steel.
  • an excessive Si content forms island-shaped martensite to generate and propagate HIC.
  • the Si content needs to be restricted to 0.50% by mass or less.
  • the Si content is preferably 0.45% by mass or less, and more preferably 0.35% by mass or less.
  • Mn is an element that is effective in improving the strengths of a base material and a welded.
  • the Mn content is set at 0.6% by mass or more.
  • the Mn content is preferably 0.8% by mass or more, and more preferably 1.0% by mass or more.
  • an extremely high Mn content forms MnS, degrading not only the hydrogen induced cracking resistance, but also the HAZ toughness and the weldability.
  • the upper limit of Mn content is set at 2.0% by mass.
  • the Mn content is preferably 1.8% by mass or less, more preferably 1.5% by mass or less, and further preferably 1.2% by mass or less.
  • the P content is an element inevitably contained in a steel material.
  • the P content exceeds 0.030% by mass, the toughness of a base material and a HAZ are significantly degraded, and the hydrogen induced cracking resistance of a steel plate is also degraded.
  • the P content is restricted to 0.030% by mass or less.
  • the P content is preferably 0.020% by mass or less, and more preferably 0.010% by mass or less.
  • S is an element that forms a large amount of MnS to significantly degrade the hydrogen induced cracking resistance when contained in a large amount.
  • the upper limit of S content is set at 0.003% by mass.
  • the S content is preferably 0.002% by mass or less, more preferably 0. 0015% by mass or less, and further preferably 0.0010% by mass or less.
  • the S content is desirably low from the viewpoint of improving the hydrogen induced cracking resistance.
  • Al is a strong deoxidizing element.
  • the Al content needs to be 0.010% by mass or more.
  • the Al content is preferably 0.020% by mass or more, and more preferably 0.030% by mass or more.
  • the Al content needs to be 0.080% by mass or less.
  • the Al content is preferably 0.060% by mass or less, and more preferably 0.050% by mass or less.
  • Ca serves to control a form of a sulfide and has an effect of suppressing formation of MnS by forming CaS.
  • the Ca content needs to be 0.0003% by mass or more.
  • the Ca content is preferably 0.0005% by mass or more, and more preferably 0.0010% by mass or more.
  • the upper limit of Ca content is set at 0. 0060% by mass.
  • the Ca content is preferably 0.0045% by mass or less, more preferably 0.0035% by mass or less, and further preferably 0.0025% by mass.
  • N is an element that is precipitated as TiN in a steel microstructure to thereby suppress coarsening of austenite grains in a HAZ and to promote ferrite transformation, thus improving the toughness of the HAZ.
  • the N content needs to be 0.001% by mass or more.
  • the N content is preferably 0.003% by mass or more, and more preferably 0.0040% by mass or more.
  • An excessive N content degrades the HAZ toughness in the presence of solid-solution N.
  • the N content needs to be 0.01% by mass or less.
  • the N content is preferably 0.008% by mass or less, and more preferably 0.0060% by mass or less.
  • O content is desirably low from the viewpoint of improving cleanliness.
  • An extremely high O content degrades the toughness, and additionally causes HIC at an oxide as a starting point, thereby degrading the hydrogen induced cracking resistance.
  • the O content needs to be 0.0045% by mass or less and is preferably 0.0035% by mass or less, and more preferably 0.0030% by mass or less.
  • the steel plate according to the present invention satisfies the following formula (1). 3.0 ⁇ Ca / S where [Ca] and [S] are contents (% by mass) of Ca and S respectively.
  • the value of [Ca]/[S] needs to be set at 3.0 or more.
  • the value of [Ca]/[S] is preferably 3.5 or more, and more preferably 4.0 or more.
  • the upper limit of [Ca]/[S] is approximately 15.
  • the steel plate according to the present invention satisfies the following formula (2).
  • the value of ([Ca] - 1.25 ⁇ [S])/[O] is preferably 1.40 or less, more preferably 1.30 or less, further preferably 1.20 or less, and particularly preferably 1.00 or less.
  • the lower limit of ([Ca] - 1.25 ⁇ [S]) is approximately 0.1 from the viewpoint of suppressing Al 2 O 3 that easily forms aggregates, like CaO.
  • the basic components of the steel plate according to the present invention are as described above, with the balance being iron and inevitable impurities. It is noted that inevitable impurities, other than P and S, which are brought depending on situations, such as raw materials, other materials, or facilities, are obviously allowed to be contained in the steel.
  • the steel plate of the present invention may further selectively contain the following element(s) in addition to the above-mentioned elements, and thereby will have more improved properties of the steel plate itself depending on the kinds of the elements contained.
  • B enhances the hardenability of a steel and the strengths of a base material and a welded part.
  • B binds with N in the process of cooling a heated HAZ during welding to precipitate BN, which promotes ferrite transformation from austenite grains, thereby improving the HAZ toughness.
  • the B content is preferably 0.0002% by mass or more.
  • the B content is more preferably 0.0005% by mass or more, and further preferably 0.0010% by mass or more.
  • An excessive B content degrades the toughness of the base material and the HAZ and leads to degradation in the weldability.
  • the B content is 0.005% by mass or less.
  • the B content is more preferably 0.004% by mass or less, and further preferably 0.0030% by mass or less.
  • V is an element effective in improving the strength.
  • the V content is preferably 0.003% by mass or more.
  • the V content is more preferably 0.010% by mass or more.
  • the V content exceeds 0.1% by mass, the weldability and the toughness of the base material are degraded.
  • the V content is 0.1% by mass or less, and more preferably 0.08% by mass or less.
  • the Cu is an element effective in improving the hardenability to enhance the strength.
  • the Cu content is preferably 0.01% by mass or more.
  • the Cu content is more preferably 0.05% by mass or more, and further preferably 0.10% by mass or more.
  • the toughness is degraded.
  • the Cu content is 1.5% by mass or less.
  • the Cu content is more preferably 1.0% by mass or less, and further preferably 0.50% by mass or less.
  • Ni is an element effective in improving the strength and toughness of a base material and a welded part.
  • the Ni content is preferably 0.01% by mass or more.
  • the Ni content is more preferably 0.05% by mass or more, and further preferably 0.10% by mass or more.
  • An excessive Ni content makes the steel plate for structures extremely expensive. From the economic point of view, the Ni content is 1.5% by mass or less.
  • the Ni content is more preferably 1.0% by mass or less, and further preferably 0.50% by mass or less.
  • the Cr content is an element effective in improving the strength.
  • the Cr content is preferably 0.01% by mass or more.
  • the Cr content is more preferably 0.05% by mass or more, and further preferably 0.10% by mass or more.
  • the Cr content exceeds 1.5% by mass, the HAZ toughness is degraded.
  • the Cr content is 1.5% by mass or less .
  • the Cr content is more preferably 1. 0% by mass or less, and further preferably 0.50% by mass or less.
  • Mo is an element that is effective in improving the strength and toughness of a base material.
  • the Mo content is preferably 0.01% by mass or more.
  • the Mo content is more preferably 0.05% by mass or more, and further preferably 0.10% by mass or more.
  • the Mo content exceeds 1.5% by mass, the HAZ toughness and the weldability are degraded.
  • the Mo content is 1.5% by mass or less, more preferably 1.0% by mass or less, and further preferably 0.50% by mass or less.
  • the Nb content is an element that is effective in enhancing the strength and the base material toughness without degrading the weldability .
  • the Nb content is preferably 0.002% by mass or more.
  • the Nb content is more preferably 0.010% by mass or more, and further preferably 0.020% by mass or more.
  • the upper limit of Nb content is 0.06% by mass.
  • the Nb content is more preferably 0.050% by mass or less, more further preferably 0.040% by mass or less, and yet more preferably 0.030% by mass or less.
  • Ti is an element that is precipitated as TiN in a steel to prevent the coarsening of austenite grains at a HAZ during welding and to promote ferrite transformation, thus improving the toughness of the HAZ.
  • Ti is also the element that is effective in improving the HIC resistance of the steel plate because of its desulfurization effect.
  • the Ti content is preferably 0.003% by mass or more.
  • the Ti content is more preferably 0.005% by mass or more, and further preferably 0.010% by mass or more.
  • an excessive Ti content precipitates solid-solution Ti and TiC to degrade the toughnesses of the base material and the HAZ.
  • the Ti content is 0.03% by mass or less.
  • the Ti content is more preferably 0.02% by mass or less.
  • Mg is an element that is effective in improving the toughness through refinement of crystal grains and also in improving the HIC resistance because of its desulfurization effect. To obtain these effects, the Mg content is preferably 0. 0003% by mass or more. The Mg content is more preferably 0.001% by mass or more. On the other hand, even when Mg is contained in an excessive amount, its effects are saturated. Thus, the upper limit of the Mg content is 0.01% by mass. The Mg content is more preferably 0.005% by mass or less.
  • the REM are elements that are effective in enhancing the hydrogen induced cracking resistance by suppressing the formation of MnS through the desulfurization effect.
  • the REM content is preferably 0.0002% by mass or more.
  • the REM content is more preferably 0.0005% by mass or more, and further preferably 0.0010% by mass or more.
  • the upper limit of the REM content is 0.02% by mass.
  • the REM content is more preferably 0.015% by mass or less, further preferably 0.010% by mass or less, and more further preferably 0.0050% by mass or less.
  • the above-mentioned REM means lanthanoid elements (15 elements from La to Lu), Sc (scandium), and Y (yttrium).
  • the Zr content is preferably set at 0.0003% by mass or more.
  • the Zr content is more preferably 0.0005% by mass or more, further preferably 0.0010% by mass or more, and yet more preferably 0.0015% by mass or more.
  • the addition of an excessive content of Zr forms coarse inclusions to degrade the hydrogen induced cracking resistance and the toughness of a base material.
  • the Zr content is 0.010% by mass or less.
  • the Zr content is more preferably 0.0070% by mass or less, further preferably 0.0050% by mass or less, and more further preferably 0.0030% by mass or less.
  • an area ratio of a part that has a defect echo height of 20% or more is 0.05% or less.
  • Ar gas needs to be blown into a molten steel, for example, in order to suppress clogging of an injection nozzle, to cause reflux for degassing in an RH, and to stir the molten steel in a tundish.
  • the slab accumulation zone is a surface part of the slab, and the part that has been cooled and solidified earlier than the center at the stage of formation of the slab.
  • bubbles caused by Ar gas blown thereinto during slab casting float, but are more likely to be trapped and remain in a solidified part of a curved portion.
  • the bubbles remaining in the slab accumulation zone are difficult to completely compress in a rolling process, so that these bubbles are more likely to remain in the steel plate accumulation zone. Since hydrogen tend to be accumulated in the bubbles remaining in the steel plate accumulation zone, HIC may occur from the remaining bubbles as a starting point. Due to this, the HIC resistance can be improved by reducing the bubbles in the steel plate accumulation zone.
  • the "slab accumulation zone” means a region of t/8 to t/4 from the surface of the slab where t is a thickness of the slab
  • the "steel plate accumulation zone” means a region of t'/8 to t'/4 from the surface of a steel plate where t' is a thickness of the steel plate, which is obtained by hot-rolling the above-mentioned slab having the thickness t.
  • the slab When a slab is hot-rolled, the slab is normally rolled almost uniformly (that is, the slab accumulation zone and other portions are rolled at the approximately same rolling reduction) .
  • the region of t/8 to t/4 from the surface of the slab becomes a part corresponding to the region of t'/8 to t'/4 from the surface of the steel plate obtained by hot-rolling the slab. That is, the "slab accumulation zone" is the part corresponding to the "steel plate accumulation zone" of the steel plate obtained by hot-rolling the slab.
  • FIG. 1 shows the result obtained by examining the relationship between the CLR of the surface layer part measured by an HIC test and an area ratio of a part that has a defect echo height of 20% or more, which is measured by an ultrasonic flaw detection test.
  • the defect echo height as used herein means a ratio [%] of an intensity of a defect echo reflected by a defect inside a test piece (taken out from a part of the steel plate) to an intensity of a bottom-surface echo reflected by the bottom surface of the steel plate (or test piece).
  • the area ratio of a part that has a defect echo height of 20% or more means a ratio [%] of the area of the part that has a defect echo height of 20% or more to the entire area of the steel plate scanned by a probe.
  • the present inventors have found a correlation between the CLR of the surface layer part and the above-mentioned area ratio. That is, it has been found that even when bubbles remain in the steel plate accumulation zone, as long as the area ratio of the part that has a defect echo height of 20% or more is 0.05% or less, the CLR of the surface layer part of the steel plate can be 10% or less, thereby the occurrence of HIC from the steel plate accumulation zone is suppressed.
  • the defect echo height is preferably 30% or less, and more preferably 25% or less
  • the area ratio of the part that has a defect echo height of 20% or more is preferably 0.04% or less, and more preferably 0.03% or less.
  • the defect echo height and the area ratio of the part that has a defect echo height of 20% or more are usually 0% or more.
  • the steel plate according to an embodiment of the present invention and a steel pipe for a line pipe formed using the steel plate may be preferably for use in line pipes for transportation, storage tanks, and pressure vessels for purification, of natural gas and crude oil.
  • a method for producing a steel plate according to the present invention uses a slab having the above-mentioned chemical composition, the slab having a number density of bubbles of 0.15 bubbles/cm 2 or less in a slab accumulation zone, the bubbles having a circular equivalent diameter of 0.2 mm or more. By using such a slab, the steel plate with excellent HIC resistance can be produced.
  • HIC since hydrogen tends to be accumulated in the bubbles remaining in the steel plate accumulation zone, HIC may occur from the remaining bubbles as a starting point. Thus, the HIC resistance can be improved by reducing the bubbles in the steel plate accumulation zone.
  • the "slab accumulation zone” is a part corresponding to the "steel plate accumulation zone” of the steel plate obtained by hot-rolling, as a specific means for reducing bubbles in the steel plate accumulation zone, it is effective to reduce bubbles in the slab accumulation zone so as to the bubbles in the steel plate accumulation zone of the steel plate obtained by hot-rolling. Consequently, the HIC resistance can be improved.
  • FIG. 2 shows the result obtained by examining the relationship between the CLR of the surface layer part measured by the HIC test and the number density of bubbles having a circular equivalent diameter of 0.2 mm or more in a slab accumulation zone.
  • the present inventors have found that the steel plate is produced by using the slab having the number density of bubbles of 0.15 bubbles/cm 2 or less in the slab accumulation zone, the bubbles having a circular equivalent diameter of 0.2 mm or more, thereby it is possible to reduce the remaining bubbles that have remained in the rolling process without being completely compressed.
  • the area ratio of the part that has a defect echo height of 20% or more can be 0.05% or less, and the CLR of the surface layer part of the steel plate can be 10% or less, thereby HIC from the steel plate accumulation zone is suppressed.
  • the circular equivalent diameter of the bubbles in the slab accumulation zone is preferably 0.17 mm or less, and more preferably 0.15 mm or less.
  • the number density of bubbles having a circular equivalent diameter of 0.2 mm or more in the slab accumulation zone is preferably 0.10 bubbles/cm 2 or less, and more preferably 0.05 bubbles/cm 2 or less.
  • the circular equivalent diameter of the bubbles in the slab accumulation zone is normally 0 mm or more, and the number density of bubbles having a circular equivalent diameter of 0.2 mm or more in the slab accumulation zone is usually 0 bubble/cm 2 or more.
  • Methods of measuring a circular equivalent diameter of the bubble and the number density of bubbles may include, but are not particularly limited to, for example, the following methods.
  • a test piece taken out from the slab accumulation zone is observed by an optical microscope, and circular equivalent diameters of bubbles are measured with an ocular micrometer to count the number of bubbles with a circular equivalent diameter of 0.2 mm or more in the observation field of view.
  • the bubble density is calculated from the area of the observation field of view and the number of bubbles having a circular equivalent diameter of 0.2 mm or more.
  • the bubbles In order to cast the slab that has the number density of bubbles of 0.15 bubbles/cm 2 or less in the slab accumulation zone, the bubbles having a circular equivalent diameter of 0.2 mm or more, it is important to control the amount of Ar gas blown into a nozzle and the diameter of the bubble when a molten steel is supplied from the tundish to a mold during a steel making process.
  • the Ar gas needs to be blown in through a porous brick which has an inner tube diameter of 70 mm or more and 115 mm or less and an average pore diameter of 30 ⁇ m or more and 60 ⁇ m or less, at a back pressure of 1.4 kgf/cm 2 or more and 1.8 kgf/cm 2 or less and at 3 L (liter) /t (ton) or more and 10 L/t or less.
  • the inner tube diameter is preferably 75 mm or more and more preferably 80 mm or more, and is also preferably 110 mm or less and more preferably 105 mm or less.
  • the average pore diameter is preferably 35 ⁇ m or more and more preferably 40 ⁇ m or more, and is also preferably 55 ⁇ m or less and more preferably 50 ⁇ m or less.
  • the back pressure is preferably 1.45 kgf/cm 2 or more, and more preferably 1.5 kgf/cm 2 or more, and is also preferably 1.75 kgf/cm 2 or less and more preferably 1.7 kgf/cm 2 or less.
  • the amount of Ar gas blown in is preferably 5 L/t or more and more preferably 7 L/t or more, and is also preferably 12 L/t or less and 10 L/t or less.
  • the nozzle By blowing Ar gas within these ranges, the nozzle is less likely to be clogged. Furthermore, as the Ar gas flow with a large diameter is blown into the molten steel, bubbles of Ar gas are more likely to float in the mold. Consequently, the bubbles of Ar gas are easily removed from the accumulation zone, which can reduce the amount of bubbles of Ar gas trapped in the accumulation zone.
  • Conditions other than those mentioned above are not particularly limited, and a steel having the above-mentioned chemical composition may be melted according to a usual steel making method to cast a slab by a continuous casting process.
  • the method for producing the steel plate according to an embodiment of the present invention using the above-mentioned slab is not particularly limited as long as the area ratio of a part that has the defect echo height of 20% or more is 0.05% or less.
  • the steel plate can be produced by the hot-rolling, followed by cooling.
  • temperature refers to a temperature of a material.
  • the hot-rolling is recommended to be performed, for example, at a rolling reduction of 20% or less per pass for five or more passes in a range of surface temperatures of 900°C or higher to reach a cumulative rolling reduction of 50% or more.
  • the surface layer part in the thickness direction is more preferentially deformed than the inside in the thickness direction, so that bubbles trapped in the accumulation zone can be more effectively compressed.
  • the cooling conditions taken after the hot-rolling are recommended in which cooling is performed, for example, from a cooling start temperature of Ar3 transformation point or higher at an average cooling rate of 10°C/s or more.
  • a steel pipe for a line pipe can be produced by a general method, using the steel plate according to an embodiment of the present invention.
  • the steel pipe for a line pipe obtained by using the steel plate according to an embodiment of the present invention also has excellent HIC resistance and toughness.
  • the steel plate according to an embodiment of the present invention may be for use in a pressure vessel by a general method.
  • the steel plate and production method therefor according to the embodiments of the present invention have been described by focusing, especially, on the slab accumulation zone and the steel plate accumulation zone.
  • the amount of bubbles located in a part other than the accumulation zone is normally less than that located in the accumulation zone.
  • the HIC resistance of the accumulation zone is improved, so that the part other than the accumulation zone can also have excellent HIC resistance. That is, it should be noted that the effect of the present invention is not limited to the accumulation zone only, but can be exhibited across the whole of the steel plate.
  • the notation "O” indicates a method in which Ar gas was blown into a tundish through a porous brick with an inner tube diameter of 90 mm and an average pore diameter of 45 ⁇ m, at a back pressure of 1.4 to 1.8 kgf/cm 2 and at 5 to 9 L/t, thereby obtaining a slab with a thickness of 280 mm by continuous casting.
  • the notation "x" indicates a method in which Ar gas was blown into the tundish through a porous brick with an inner tube diameter of 120 to 150 mm and an average pore diameter of 45 ⁇ m, at a back pressure of 1.4 to 1.8 kgf/cm 2 and at 5 to 9 L/t, thereby obtaining a slab with a thickness of 280 mm by the continuous casting.
  • the obtained slabs were reheated to a temperature between 1,050°C and 1,250°C, and then subjected to one of two patterns of processes shown in Table 2, and thus the steel plates of tests Nos. 1 to 12 were produced.
  • the process "TMCP” refers to a method which includes (1) hot-rolling the steel plate at a rolling reduction of 20% or less per pass for five or more passes in a range of temperatures of 900°C or higher so as to reach a cumulative rolling reduction of 50% or more, (2) hot-rolling the steel plate in a range of temperatures of 850°C or higher and lower than 900°C so as to reach a cumulative rolling reduction of 20% or more and a rolling end temperature of 850 to 900 °C, and (3) cooling from a cooling start temperature of 750 to 850°C at an average cooling rate of 10 to 50°C/s and then stopping the cooling in a range of temperatures of 350 to 600°C, followed by air-cooling to the room temperature.
  • the process "QT” refers to a method which includes (1) hot-rolling the steel plate at a rolling reduction of 20% or less per pass for five or more passes in a range of temperatures of 900°C or higher so as to reach a cumulative rolling reduction of 50% or more and a rolling end temperature of 850°C or higher, (2) air-cooling to the room temperature, (3) reheating to a temperature between the 850°C to 950°C and then hardening, and (4) tempering at a temperature between 600°C and 700°C.
  • the number density of bubbles having a circular equivalent diameter of 0.2 mm or more in the slab accumulation zone, as well as the area ratio of the part that had a defect echo height of 20% or more were measured, and the HIC test was performed on the steel plates, according to the following procedures.
  • the L cross section of each test piece was polished using emery polishing paper (#320 to #1500), followed by mirror finishing through buffing.
  • the L cross section of the test piece was observed using an optical microscope (magnification: 5 times), and circular equivalent diameters of the bubbles were measured using an ocular micrometer (magnification: 5 times), whereby the number of bubbles having a circular equivalent diameter of 0.2 mm or more was counted in the observation field of view.
  • the density of bubbles was calculated from the area of the observation field and the number of bubbles having the circle equivalent diameter of 0.2 mm or more.
  • the maximum value of the densities obtained from the above-mentioned two sites was referred to as the number density of bubbles having the circular equivalent diameter of 0.2 mm or more in the slab accumulation zone.
  • Test pieces were respectively taken from two sites (steel plate accumulation zones) of the steel plate, located at positions corresponding to 1/4 and 1/2 of the width of the steel plate along its width direction (direction perpendicular to the rolling direction), depending on the thickness of the steel plate in the following ways.
  • Step plate having a thickness of 30 mm or less (Steel plate having a thickness of 30 mm or less)
  • test pieces each having a thickness of the steel plate ⁇ 20 mm width ⁇ 100 mm length (in the rolling direction), were taken from each of the above-mentioned two positions. Consequently, the six test pieces in total were prepared.
  • test pieces each having 30 mm thickness ⁇ 20 mm width ⁇ 100 mm length, were taken (i) from the surface of the steel plate in the direction perpendicular to the surface, (ii) from the position of 1/2 of the thickness of the steel plate, and (iii) from the back surface of the steel plate in the direction perpendicular to the back surface. Consequently, the six test pieces in total were prepared.
  • Each test piece was subjected to an ultrasonic flaw detection test at a pitch of 0.4 mm ⁇ 0.4 mm using an ultrasonic flaw detector "GSONIC SCAN 8AX1500SR" manufactured by GNES Corporation, and a water immersion probe (frequency: 10 MHz, diameter: 0.5 inches, focal depth: 4.5 inches).
  • An area ratio of a part of the test piece that had a defect echo height of 20% or more was measured, and an average of the measured area ratios was referred to as an area ratio of the part that had the defect echo height of 20% or more.
  • the HIC test was performed on the test piece used in the above-mentioned ultrasonic flaw detection test, according to the method specified by the NACE standard TM0284-2003.
  • the test piece was immersed in an aqueous solution (5.0% NaCl + 0.5% acetic acid) with 1 atm of hydrogen sulfide saturated therein, at 25°C for 96 hours.
  • the cross section of each test piece was evaluated (according to NACE standard TM0284-2003 FIGURES 2 to 8), depending on the thickness of the steel plate to thereby measure a CLR of each test piece in the following way.
  • the cross section is a plane defined by the thickness direction and the width direction of the test piece.
  • Step plate having a thickness of 30 mm or less (Steel plate having a thickness of 30 mm or less)
  • the cross section of each test piece was equally divided into three pieces in the thickness direction, namely, three cross sections on the surface side, the center, and the back surface side.
  • the CLRs of the cross section on the surface side were measured, and an average of the measured CLRs was referred to as a "CLR of the surface layer part".
  • the CLRs of the cross section at its center were measured, and an average of the measured CLRs was referred to as a "CLR of the center”.
  • CLR of the surface layer part The CLRs of the test piece taken from the surface of the steel plate in the direction perpendicular to the surface were measured, and an average of the measured CLRs was referred to as a "CLR of the surface layer part".
  • CLR of the center the CLRs of the test piece taken from the position located at 1/2 of the thickness of the steel plate in its thickness direction were measured, and an average of the measured CLRs was referred to as a "CLR of the center”.
  • the steel plate in which each of the CLR of the surface layer part and the CLR of the center was 10% or less was evaluated to be a practical standard one and to have excellent HIC resistance.
  • Table 2 shows the measurement results of the number density of bubbles having the circular equivalent diameter of 0.2 mm or more in the slab accumulation zone, the area ratio of the part that had a defect echo height of 20% or more, the CLR of the surface layer part, and the CLR of the center.
  • the test pieces in which each of the CLR of the surface layer part and the CLR of the center was 10% or less were indicated by the notation "O".
  • tests Nos. 6 to 11 are examples that did not satisfy any one of the requirements specified by the embodiments of the present invention.
  • the tests Nos. 6 and 7 are examples of the steel plate in which the casting conditions were not appropriate and each of the used slabs had the large number density of bubbles having a circular equivalent diameter of 0.2 mm or more in the slab accumulation zone. Consequently, in the steel plates of these tests, the area ratio of the part that had the defect echo height of 20% or more was large, thus the CLR of the surface layer part was deteriorated, so that the desired HIC resistance could not be achieved.
  • the tests Nos. 8 and 9 are examples of the steel plate in which the steel plates were produced using steel materials of the steel types G and H, respectively, that had small ratios of [Ca]/[S]. Consequently, in the steel plates of these tests, a large amount of MnS was generated to deteriorate the CLR of the center, so that the desired HIC resistance could not be achieved. In the test No. 8, the CLR of the center was deteriorated, and thus the number density of bubbles was not evaluated.
  • the tests Nos. 10 and 11 are examples of the steel plate in which the steel plates were produced using the steels of the steel types I and J, respectively, that had large ratios of ([Ca] - 1.25 ⁇ [S])/[O]. Consequently, in the steel plates of these tests, coarse Ca inclusions were formed in the steel plate accumulation zone, thus the CLR of the surface layer part was deteriorated, so that the desired HIC resistance could not be achieved.

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)
EP17871656.9A 2016-11-16 2017-11-02 Steel sheet, steel pipe for line pipe, and production method therefor Active EP3543366B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2016223416 2016-11-16
JP2017176045A JP6869151B2 (ja) 2016-11-16 2017-09-13 鋼板およびラインパイプ用鋼管並びにその製造方法
PCT/JP2017/039785 WO2018092605A1 (ja) 2016-11-16 2017-11-02 鋼板およびラインパイプ用鋼管並びにその製造方法

Publications (3)

Publication Number Publication Date
EP3543366A1 EP3543366A1 (en) 2019-09-25
EP3543366A4 EP3543366A4 (en) 2020-05-27
EP3543366B1 true EP3543366B1 (en) 2022-10-05

Family

ID=62236616

Family Applications (1)

Application Number Title Priority Date Filing Date
EP17871656.9A Active EP3543366B1 (en) 2016-11-16 2017-11-02 Steel sheet, steel pipe for line pipe, and production method therefor

Country Status (4)

Country Link
EP (1) EP3543366B1 (zh)
JP (1) JP6869151B2 (zh)
KR (1) KR102226990B1 (zh)
CN (1) CN109952387B (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110592462B (zh) * 2019-09-19 2021-04-06 舞阳钢铁有限责任公司 一种低温设备用钢板及其生产方法
CN117187679A (zh) * 2022-05-30 2023-12-08 宝山钢铁股份有限公司 一种高强度石油套管及其制造方法

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2721420B2 (ja) * 1990-09-11 1998-03-04 新日本製鐵株式会社 耐サワー電縫鋼管用鋼
JPH04329826A (ja) * 1991-04-30 1992-11-18 Nippon Steel Corp 耐水素誘起割れ性の優れた圧力容器用極厚鋼板の製造方法
JP2914138B2 (ja) 1993-11-17 1999-06-28 住友金属工業株式会社 高耐食性電縫鋼管用鋼の製造方法
JP3890748B2 (ja) * 1998-06-19 2007-03-07 Ｊｆｅスチール株式会社 伸びフランジ性、耐遅れ破壊特性に優れる高強度鋼板
JP2006063351A (ja) * 2004-08-24 2006-03-09 Sumitomo Metal Ind Ltd 耐水素誘起割れ性に優れた高強度鋼板および製造方法、並びにラインパイプ用鋼管
JP4940886B2 (ja) * 2006-10-19 2012-05-30 Ｊｆｅスチール株式会社 耐ｈｉｃ特性に優れたラインパイプ用高強度鋼板およびその製造方法
JP5423324B2 (ja) * 2009-02-12 2014-02-19 新日鐵住金株式会社 耐水素誘起割れ性に優れた高強度ラインパイプ用鋼板及び高強度ラインパイプ用鋼管
JP5423323B2 (ja) * 2009-02-12 2014-02-19 新日鐵住金株式会社 耐水素誘起割れ性に優れた高強度ラインパイプ用鋼板及び高強度ラインパイプ用鋼管
WO2013147197A1 (ja) * 2012-03-30 2013-10-03 新日鐵住金株式会社 耐水素誘起割れ性に優れた高強度ラインパイプ用鋼管及びこれに用いる高強度ラインパイプ用鋼板、並びにこれらの製造方法
JP5824401B2 (ja) * 2012-03-30 2015-11-25 株式会社神戸製鋼所 耐水素誘起割れ性に優れた鋼板およびその製造方法
CN102644018B (zh) * 2012-05-08 2013-09-25 首钢总公司 一种用于抗氢致开裂管线钢中厚板板坯的冶炼工艺
JP5598618B1 (ja) * 2013-03-26 2014-10-01 Ｊｆｅスチール株式会社 脆性亀裂伝播停止特性に優れた大入熱溶接用高強度厚鋼板およびその製造方法
JP6165088B2 (ja) * 2013-03-29 2017-07-19 株式会社神戸製鋼所 耐水素誘起割れ性と溶接熱影響部の靭性に優れた鋼板およびラインパイプ用鋼管
JP6316548B2 (ja) * 2013-07-01 2018-04-25 株式会社神戸製鋼所 耐水素誘起割れ性と靭性に優れた鋼板およびラインパイプ用鋼管
RU2623569C1 (ru) * 2013-07-25 2017-06-27 Ниппон Стил Энд Сумитомо Метал Корпорейшн Толстолистовая сталь для магистральной трубы и магистральная труба
JP2016125137A (ja) * 2014-12-26 2016-07-11 株式会社神戸製鋼所 耐水素誘起割れ性に優れた鋼板およびラインパイプ用鋼管
JP2016125140A (ja) * 2014-12-26 2016-07-11 株式会社神戸製鋼所 耐水素誘起割れ性と靭性に優れた鋼板およびラインパイプ用鋼管
JP6584912B2 (ja) * 2014-12-26 2019-10-02 株式会社神戸製鋼所 耐水素誘起割れ性に優れた鋼板およびラインパイプ用鋼管
JP2016125139A (ja) * 2014-12-26 2016-07-11 株式会社神戸製鋼所 耐水素誘起割れ性に優れた鋼板およびラインパイプ用鋼管

Also Published As

Publication number Publication date
CN109952387A (zh) 2019-06-28
EP3543366A1 (en) 2019-09-25
JP6869151B2 (ja) 2021-05-12
KR20190065337A (ko) 2019-06-11
EP3543366A4 (en) 2020-05-27
KR102226990B1 (ko) 2021-03-11
JP2018083981A (ja) 2018-05-31
CN109952387B (zh) 2021-06-18

Similar Documents

Publication Publication Date Title
KR101615842B1 (ko) 내수소 유기 균열성이 우수한 고강도 라인 파이프용 강관 및 이것에 사용하는 고강도 라인 파이프용 강판 및 이들의 제조 방법
KR101709034B1 (ko) 내수소유기균열성과 인성이 우수한 강판 및 라인 파이프용 강관
KR101524397B1 (ko) 내수소 유기 균열성이 우수한 고강도 라인 파이프용 강판 및 고강도 라인 파이프용 강관
JP5748032B1 (ja) ラインパイプ用鋼板及びラインパイプ
EP3561124A1 (en) Steel material for pressure vessels which has excellent resistance to hydrogen induced cracking and manufacturing method thereof
JP6316548B2 (ja) 耐水素誘起割れ性と靭性に優れた鋼板およびラインパイプ用鋼管
JP2006063351A (ja) 耐水素誘起割れ性に優れた高強度鋼板および製造方法、並びにラインパイプ用鋼管
EP3239320B1 (en) Steel plate and steel pipe for line pipe having excellent hydrogen-induced cracking resistance
EP3239333A1 (en) Steel plate having excellent toughness and resistance to hydrogen-induced cracking, and steel pipe for line pipe
JP6645373B2 (ja) 厚鋼板とその製造方法
EP3543366B1 (en) Steel sheet, steel pipe for line pipe, and production method therefor
JP2010121199A (ja) 溶接熱影響部の靭性および母材低温靭性に優れた鋼材、並びにその製造方法
EP3239334A1 (en) Steel plate having excellent resistance to hydrogen-induced cracking, and steel pipe for line pipe
EP3239319A1 (en) Steel plate having excellent hydrogen-induced cracking resistance and steel pipe for line pipe
EP4116453A1 (en) Steel pipe and steel sheet
JPH07136748A (ja) 高耐食性電縫鋼管用鋼の製造方法
KR20240021260A (ko) 후강판 및 후강판의 제조 방법
WO2018092605A1 (ja) 鋼板およびラインパイプ用鋼管並びにその製造方法
EP3124639A1 (en) Steel sheet for high-strength line pipe having excellent low temperature toughness, and steel tube for high-strength line pipe
JPS61143555A (ja) 耐水素誘起割れ性の優れた鋼
KR20230155516A (ko) 강판 및 그 제조 방법
WO2016104529A1 (ja) 耐水素誘起割れ性に優れた鋼板およびラインパイプ用鋼管
JPH05271884A (ja) Ｂａ酸化物を含む微小粒子が分散した鋼

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: 20190418

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)
A4 Supplementary search report drawn up and despatched

Effective date: 20200423

RIC1 Information provided on ipc code assigned before grant

Ipc: C22C 38/54 20060101ALI20200417BHEP

Ipc: C22C 38/02 20060101ALI20200417BHEP

Ipc: C22C 38/48 20060101ALI20200417BHEP

Ipc: B22D 11/10 20060101ALI20200417BHEP

Ipc: C22C 38/00 20060101AFI20200417BHEP

Ipc: C22C 38/04 20060101ALI20200417BHEP

Ipc: C21D 9/00 20060101ALI20200417BHEP

Ipc: C22C 38/06 20060101ALI20200417BHEP

Ipc: B22D 11/00 20060101ALI20200417BHEP

Ipc: C22C 38/50 20060101ALI20200417BHEP

Ipc: C22C 38/44 20060101ALI20200417BHEP

Ipc: C21D 9/08 20060101ALI20200417BHEP

Ipc: C22C 38/46 20060101ALI20200417BHEP

Ipc: C21D 8/02 20060101ALI20200417BHEP

Ipc: C22C 38/58 20060101ALI20200417BHEP

Ipc: C22C 38/42 20060101ALI20200417BHEP

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

INTG Intention to grant announced

Effective date: 20220426

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: GB

Ref legal event code: FG4D

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: 1522794

Country of ref document: AT

Kind code of ref document: T

Effective date: 20221015

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: 602017062476

Country of ref document: DE

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG9D

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20221005

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1522794

Country of ref document: AT

Kind code of ref document: T

Effective date: 20221005

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: 20221005

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

Ref country code: SE

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: 20221005

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: 20230206

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: 20230105

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: 20221005

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: 20221005

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: 20221005

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: 20221005

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

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: 20221005

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: 20221005

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: 20221005

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: 20230205

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: 20221005

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: 20230106

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602017062476

Country of ref document: DE

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230523

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

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

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: 20221005

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: 20221005

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: 20221005

Ref country code: LI

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

Effective date: 20221130

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: 20221005

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: 20221005

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: 20221005

Ref country code: CH

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

Effective date: 20221130

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: 20221005

Ref country code: LU

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

Effective date: 20221102

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: 20221005

26N No opposition filed

Effective date: 20230706

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

Effective date: 20230105

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: 20221102

Ref country code: GB

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

Effective date: 20230105

Ref country code: DE

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

Effective date: 20230601

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

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: 20221005

Ref country code: FR

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

Effective date: 20221205

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

Ref country code: HU

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

Effective date: 20171102

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

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: 20221005

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: 20221005

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: 20221005

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

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: 20221005

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

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: 20221005

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

Ref country code: BE

Payment date: 20240917

Year of fee payment: 8