WO2016104527A1 - Tôle d'acier présentant une excellente résistance à la fissuration induite par l'hydrogène et tube d'acier pour tube de canalisation - Google Patents

Tôle d'acier présentant une excellente résistance à la fissuration induite par l'hydrogène et tube d'acier pour tube de canalisation Download PDF

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WO2016104527A1
WO2016104527A1 PCT/JP2015/085870 JP2015085870W WO2016104527A1 WO 2016104527 A1 WO2016104527 A1 WO 2016104527A1 JP 2015085870 W JP2015085870 W JP 2015085870W WO 2016104527 A1 WO2016104527 A1 WO 2016104527A1
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Prior art keywords
steel plate
less
slab
hic
threshold value
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PCT/JP2015/085870
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English (en)
Japanese (ja)
Inventor
喜一郎 田代
加藤　拓
晴弥 川野
佑一 岡
進佑 佐藤
木村　世意
孝司 三宅
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株式会社神戸製鋼所
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Priority claimed from JP2015207452A external-priority patent/JP6584912B2/ja
Application filed by 株式会社神戸製鋼所 filed Critical 株式会社神戸製鋼所
Priority to KR1020177019243A priority Critical patent/KR20170093965A/ko
Priority to CN201580069985.6A priority patent/CN107109565A/zh
Priority to KR1020197035849A priority patent/KR102141794B1/ko
Priority to EP15873095.2A priority patent/EP3239320B1/fr
Publication of WO2016104527A1 publication Critical patent/WO2016104527A1/fr

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    • 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
    • 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
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing 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
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • 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

Definitions

  • the present invention relates to a steel plate having excellent resistance to hydrogen-induced cracking.
  • steel plates excellent in hydrogen-induced crack resistance suitable for natural gas and crude oil transportation line pipes and storage tanks, and steel pipes for line pipes excellent in hydrogen-induced crack resistance obtained using the steel plates About are excellent resistance to hydrogen-induced cracking.
  • sour resistance such as resistance to hydrogen-induced cracking and stress corrosion cracking
  • the steel plate having sour resistance may be referred to as “sour-resistant steel plate”.
  • Hydrogen-induced cracking Hydrogen-induced cracking (Hydrogen Induced Cracking, hereinafter sometimes referred to as "HIC”) is caused by hydrogen intruding into the steel material due to the corrosion reaction caused by hydrogen sulfide or the like, including MnS and Nb (C, N). It is known that it is a crack that accumulates in non-metallic inclusions and is caused by gasification.
  • Patent Document 1 discloses a steel material having improved HIC resistance by suppressing the segregation degree of Mn, Nb, and Ti at the center of the plate thickness.
  • Patent Document 2 discloses a method of suppressing HIC starting from MnS or Ca-based oxysulfide by a parameter formula including Ca, O, and S contents.
  • the steel sheet is obtained through melting, casting and hot rolling, and then subjected to an HIC test before shipping as a product.
  • the HIC test takes several weeks before the results are known.
  • the steel sheet cannot be shipped as a product excellent in hydrogen-induced cracking resistance, and the HIC test is performed again on the product obtained by remanufacturing, that is, remelting. There is a need to do. If it does so, a manufacturing period will become long and it will cause a delay in delivery.
  • the HIC resistance can be evaluated at the stage of the cast slab after the casting instead of performing the HIC test after the hot rolling, it is considered that the manufacturing period can be greatly shortened.
  • HIC occurs starting from the segregation part (center segregation, internal crack) and inclusions such as MnS, if these can be evaluated at the stage of the slab, the HIC resistance can be improved based on the evaluation result. It can be evaluated.
  • Step A-2 Casting ⁇ Rolling ⁇ Sample preparation (for HIC test) ⁇ HIC test ⁇ Remelting
  • Step B-2 Casting ⁇ Evaluation of HIC resistance ⁇ Remelting
  • Patent Document 3 discloses a method for evaluating an internal crack at the stage of a slab. In this method, whether or not HCR (Hot Charge Rolling) operation is possible is determined from the evaluation result of the internal crack.
  • HCR Hot Charge Rolling
  • JP 2010-209461 Japanese Patent Laid-Open No. 06-136440 JP 2006-198649 A
  • the present invention has been made paying attention to the above-mentioned circumstances, and its purpose is to realize a steel plate and a steel pipe excellent in hydrogen-induced cracking resistance, and further, without carrying out a HIC test, It is to realize a steel plate and a steel pipe that can evaluate the HIC resistance from the internal quality of the piece.
  • a steel sheet excellent in hydrogen-induced crack resistance of the present invention that has solved the above problems is % By mass C: 0.02 to 0.15%, Si: 0.02 to 0.50%, Mn: 0.6 to 2.0%, P: more than 0% and 0.030% or less, S: more than 0% and 0.003% or less, Al: 0.010 to 0.08%, Ca: 0.0003 to 0.0060%, N: 0.001 to 0.01%, and O: more than 0% and 0.0045% or less, Including one or more elements selected from the group consisting of REM: more than 0% and 0.02% or less, and Zr: more than 0% and 0.010%, the balance consisting of iron and inevitable impurities,
  • the ratio of Ca to S (Ca / S) is 2.0 or more, and Ca, S and O satisfy (Ca-1.25S) /O ⁇ 1.80, Further, at the stage of the slab, there is no horizontal crack, or the maximum opening thickness of the horizontal crack is equal to or less than a threshold value t ⁇
  • the threshold value t ⁇ may be a value obtained in advance by the following methods (i) to (iii).
  • the maximum hole thickness of the slab is measured.
  • a hydrogen-induced cracking test is performed on a steel plate obtained by rolling a slab cast under the same casting conditions as the slab.
  • the maximum hole thickness of a horizontal crack in which no hydrogen-induced crack occurs is obtained.
  • the slab cast under the same casting conditions as the slab may be a slab in which the maximum hole thickness is measured.
  • the steel plate may be API (The American Petroleum Institute) X65 grade, and the threshold value t ⁇ may be 0.047 mm.
  • the steel plate may be APIX 70 grade, and the threshold value t ⁇ may be 0.043 mm.
  • the steel plate may be ASME (American Society of Mechanical Engineers) SA516 grade 60, and the threshold value t ⁇ may be 0.047 mm.
  • the steel plate may be ASMESA 516 grade 65, and the threshold value t ⁇ may be 0.047 mm.
  • the steel plate may be ASMESA516 grade 70, and the threshold value t ⁇ may be 0.043 mm.
  • the steel plate may be ASTM (American Society for Testing and Materials) A516 grade 60, and the threshold value t ⁇ may be 0.047 mm.
  • the steel plate may be ASTM A516 grade 65, and the threshold value t ⁇ may be 0.047 mm.
  • the steel plate may be ASTM A516 grade 70, and the threshold value t ⁇ may be 0.043 mm.
  • the said steel plate may contain any one or more of following (A) and (B) as another element.
  • the above steel plate is suitable for line pipes and pressure vessels.
  • the present invention also includes a steel pipe for line pipe formed from the steel plate.
  • the present invention it is possible to provide a steel plate and a steel pipe that are surely excellent in hydrogen-induced crack resistance. Furthermore, the steel plate and steel pipe which can evaluate HIC resistance from the internal quality of a slab can be provided, without performing a HIC test. These are suitably used for pressure vessels such as natural gas / crude oil transportation line pipes and storage tanks.
  • FIG. 1 is a schematic diagram for explaining internal cracks, in which (a) shows a slab, that is, a state before rolling, and (b) shows a product, that is, a state after rolling.
  • FIG. 2 is a cross-sectional view of the slab.
  • FIG. 3 shows a cross-sectional view of the slab and a cross-sectional view of the product.
  • FIG. 4 is a diagram showing the results of investigating the relationship between the hole thickness and the HIC resistance for a plurality of cross sections.
  • FIG. 5 is a diagram for explaining the investigation surface of the slab. It is a figure which shows the relationship between the maximum opening thickness of a horizontal crack at the time of using the steel material of APIX65 grade in an Example, and the presence or absence of HIC generation
  • the inventors of the present invention have made extensive studies to solve the above-mentioned problems.
  • the inventors focused on the fact that HIC is likely to be generated starting from MnS inclusions.
  • the rare earth element or Zr which is an element having a desulfurization action, can be contained in the steel material to suppress the generation of MnS and enhance the resistance to hydrogen-induced cracking.
  • an appropriate content described later has been found.
  • the present inventors paid attention to the fact that HIC is likely to occur starting from the segregation part.
  • the ⁇ horizontal crack '' of segregation especially the maximum hole thickness of the horizontal crack, if this is kept below a predetermined threshold at the slab stage, a steel plate with high hydrogen-induced crack resistance can be obtained, Furthermore, it has been found that products can be shipped early. This point will be described in detail later.
  • the component composition of the steel sheet needs to be as follows.
  • the reasons for defining each component including the above-described rare earth element and Zr will be described.
  • Component composition C 0.02 to 0.15% C is an indispensable element for securing the strength of the base material and the welded portion, and needs to be contained by 0.02% or more.
  • the amount of C is preferably 0.03% or more, and more preferably 0.05% or more.
  • the amount of C is too large, the HAZ toughness and weldability deteriorate.
  • the amount of C is excessive, NbC and island-shaped martensite that become the starting point of HIC and the fracture propagation path are likely to be generated. Therefore, the C amount needs to be 0.15% or less. Preferably it is 0.12% or less, More preferably, it is 0.10% or less.
  • Si 0.02 to 0.50% Si is an element that has a deoxidizing action and is effective in improving the strength of the base material and the welded portion.
  • the Si content is set to 0.02% or more.
  • the amount of Si is preferably 0.05% or more, and more preferably 0.15% or more. However, if the amount of Si is too large, weldability and toughness deteriorate. If the amount of Si is excessive, island martensite is generated and HIC is generated and progresses. Therefore, the amount of Si needs to be suppressed to 0.50% or less.
  • the amount of Si is preferably 0.45% or less, more preferably 0.35% or less.
  • Mn 0.6 to 2.0%
  • Mn is an element effective for improving the strength of the base material and the welded portion, and is contained in an amount of 0.6% or more in the present invention.
  • the amount of Mn is preferably 0.8% or more, and more preferably 1.0% or more.
  • the upper limit of the amount of Mn is set to 2.0%.
  • the amount of Mn is preferably 1.8% or less, more preferably 1.5% or less, and still more preferably 1.2% or less.
  • P more than 0% and 0.030% or less P is an element inevitably contained in the steel material. If the P content exceeds 0.030%, the toughness deterioration of the base material and the HAZ part is remarkable, and hydrogen-induced cracking resistance Also deteriorates. Therefore, in the present invention, the amount of P is suppressed to 0.030% or less.
  • the amount of P is preferably 0.020% or less, more preferably 0.010% or less.
  • S more than 0% and 0.003% or less S is an element that generates a large amount of MnS and significantly deteriorates the resistance to hydrogen-induced cracking if it is too much. Therefore, in the present invention, the upper limit of the amount of S is made 0.003%. .
  • the amount of S is preferably 0.002% or less, more preferably 0.0015% or less, and still more preferably 0.0010% or less. Thus, the smaller one is desirable from the viewpoint of improving hydrogen-induced crack resistance.
  • Al 0.010 to 0.08%
  • Al is a strong deoxidizing element.
  • the amount of Al is small, the Ca concentration in the oxide increases, that is, Ca inclusions are easily formed in the surface layer portion of the steel sheet and fine HIC is generated. Therefore, in the present invention, Al needs to be 0.010% or more.
  • the amount of Al is preferably 0.020% or more, more preferably 0.030% or more.
  • the oxide of Al will produce
  • the amount of Al is preferably 0.06% or less, and more preferably 0.05% or less.
  • Ca 0.0003 to 0.0060%
  • Ca has the effect
  • the Ca content needs to be 0.0003% or more.
  • the Ca content is preferably 0.0005% or more, and more preferably 0.0010% or more.
  • the upper limit of the Ca amount is set to 0.0060%.
  • the Ca content is preferably 0.0045% or less, more preferably 0.0035% or less, and still more preferably 0.0025% or less.
  • N 0.001 to 0.01%
  • N is an element that precipitates as TiN in the steel structure, suppresses coarsening of the austenite grains in the HAZ part, further promotes ferrite transformation, and improves the toughness of the HAZ part.
  • the N amount is preferably 0.003% or more, and more preferably 0.0040% or more.
  • the amount of N is too large, the HAZ toughness deteriorates due to the presence of solute N, so the amount of N needs to be 0.01% or less.
  • it is 0.008% or less, More preferably, it is 0.0060% or less.
  • O More than 0% and 0.0045% or less O, that is, oxygen is desirable to be low from the viewpoint of improving cleanliness, and when O is contained in a large amount, in addition to deterioration of toughness, HIC is generated starting from oxide. In addition, the resistance to hydrogen-induced cracking deteriorates. From this viewpoint, the amount of O needs to be 0.0045% or less, preferably 0.0030% or less, more preferably 0.0020% or less.
  • Ca / S represented by mass ratio: 2.0 or more
  • S forms MnS as a sulfide-based inclusion, and HIC is generated starting from the MnS.
  • Ca is added to control the form of the sulfide inclusions in the steel as CaS, thereby detoxifying S against HIC resistance.
  • Ca / S needs to be 2.0 or more.
  • Ca / S is preferably 2.5 or more, more preferably 3.0 or more.
  • the upper limit of Ca / S is about 17 from the Ca amount and S amount specified in the present invention.
  • CaO which easily forms aggregated coal, among Ca-based inclusions.
  • the Ca content (Ca-1.25S) obtained by subtracting the Ca content present as sulfide (CaS) from the total Ca content in the steel must not be excessive with respect to the O content. If the amount of Ca (Ca-1.25S) is excessive with respect to the amount of O, CaO is likely to be formed as oxide inclusions, and the aggregated coalescence (coarse Ca inclusions) of the CaO is formed on the steel sheet surface layer portion. It becomes easy to be formed in large quantities.
  • (Ca-1.25S) / O must be 1.80 or less.
  • (Ca-1.25S) / O is preferably 1.40 or less, more preferably 1.30 or less, still more preferably 1.20 or less, and particularly preferably 1.00 or less.
  • the lower limit of (Ca-1.25S) / O is about 0.1 from the viewpoint of suppressing Al 2 O 3 which is likely to form an aggregated coal like CaO.
  • REM more than 0% and 0.02% or less REM (Rare Earth Metal, a rare earth element) is an element effective for suppressing the generation of MnS by desulfurization and enhancing the resistance to hydrogen-induced cracking as described above. In order to exhibit such an effect, it is preferable to contain REM 0.0002% or more.
  • the amount of REM is more preferably 0.0005% or more, and further preferably 0.0010% or more. On the other hand, the effect is saturated even if a large amount of REM is contained. Therefore, the upper limit of the REM amount needs to be 0.02%.
  • the REM content is preferably 0.015% or less, more preferably 0.010% or less, and still more preferably 0.0047% or less. is there.
  • the REM means a lanthanoid element, that is, 15 elements from La to Lu, scandium and yttrium.
  • Zr more than 0% and 0.010% or less
  • Zr is an element that improves HIC resistance by desulfurization and contributes to improvement of HAZ toughness by forming an oxide and finely dispersing.
  • the Zr content is preferably 0.0003% or more.
  • the amount of Zr is more preferably 0.0005% or more, still more preferably 0.0010% or more, and still more preferably 0.0015% or more.
  • the amount of Zr needs to be 0.010% or less.
  • the amount of Zr is preferably 0.0070% or less, more preferably 0.0047% or less, and still more preferably 0.0030% or less.
  • the components of the steel plate and steel pipe of the present invention are as described above, and the balance is composed of iron and inevitable impurities.
  • the strength and toughness can be further increased
  • the HAZ toughness can be improved and desulfurization can be promoted to further improve the HIC resistance.
  • B More than 0% and 0.005% or less B enhances hardenability, increases the strength of the base metal and the welded part, and precipitates BN by bonding with N during the process of cooling the heated HAZ part during welding. In order to promote ferrite transformation from within the austenite grains, the HAZ toughness is improved. In order to acquire this effect, it is preferable to contain B amount 0.0002% or more.
  • the amount of B is more preferably 0.0005% or more, and further preferably 0.0010% or more. However, if the B content is excessive, the toughness between the base material and the HAZ part deteriorates or weldability deteriorates, so the B content is preferably 0.005% or less.
  • the amount of B is more preferably 0.004% or less, and still more preferably 0.0030% or less.
  • V more than 0% and 0.1% or less V is an element effective for improving the strength.
  • V is preferably contained in an amount of 0.003% or more. More preferably, it is 0.010% or more.
  • the V amount is preferably 0.1% or less, and more preferably 0.08% or less.
  • Cu more than 0% and 1.5% or less Cu is an element effective for improving the hardenability and increasing the strength. In order to acquire this effect, it is preferable to contain 0.01% or more of Cu.
  • the amount of Cu is more preferably 0.05% or more, and still more preferably 0.10% or more. However, if the Cu content exceeds 1.5%, the toughness deteriorates, so it is preferable to set it to 1.5% or less.
  • the amount of Cu is more preferably 1.0% or less, still more preferably 0.50% or less.
  • Ni more than 0% and 1.5% or less
  • Ni is an element effective for improving the strength and toughness of the base material and the welded portion.
  • the Ni content is preferably 0.01% or more.
  • the amount of Ni is more preferably 0.05% or more, and still more preferably 0.10% or more.
  • the Ni content is preferably 1.5% or less from an economical viewpoint.
  • the amount of Ni is more preferably 1.0% or less, and still more preferably 0.50% or less.
  • Cr more than 0% and 1.5% or less Cr is an element effective for improving the strength. To obtain this effect, it is preferable to contain 0.01% or more.
  • the amount of Cr is more preferably 0.05% or more, and still more preferably 0.10% or more.
  • the Cr content is preferably 1.5% or less.
  • the amount of Cr is more preferably 1.0% or less, and still more preferably 0.50% or less.
  • Mo more than 0% and 1.5% or less Mo is an element effective for improving the strength and toughness of the base material.
  • the Mo amount is preferably 0.01% or more.
  • the amount of Mo is more preferably 0.05% or more, and still more preferably 0.10% or more.
  • the Mo amount is preferably 1.5% or less, more preferably 1.0% or less, and still more preferably 0.50% or less.
  • Nb more than 0% and 0.06% or less
  • Nb is an element effective for increasing strength and base metal toughness without degrading weldability.
  • the Nb content is preferably 0.002% or more.
  • the Nb amount is more preferably 0.010% or more, and still more preferably 0.020% or more.
  • the upper limit of the Nb amount is preferably 0.06%.
  • the Nb amount is more preferably 0.047% or less, still more preferably 0.040% or less, and still more preferably 0.030% or less.
  • Ti more than 0% and 0.03% or less Ti precipitates as TiN in the steel to prevent coarsening of austenite grains in the HAZ part during welding and promote ferrite transformation, so that the toughness of the HAZ part It is an effective element for improving Further, Ti is an element effective for improving the HIC resistance since it exhibits a desulfurization action. In order to obtain these effects, it is preferable to contain 0.003% or more of Ti.
  • the amount of Ti is more preferably 0.005% or more, and still more preferably 0.010% or more.
  • the Ti content is excessive, the toughness of the base material and the HAZ part deteriorates due to an increase in solid solution Ti or an increase in TiC precipitation, so 0.03% or less is preferable.
  • the amount of Ti is more preferably 0.02% or less.
  • Mg more than 0% and 0.01% or less Mg is an element effective for improving toughness through refinement of crystal grains, and is also an element effective for improving HIC resistance because of its desulfurization action. In order to acquire these effects, it is preferable to contain 0.0003% or more of Mg.
  • the amount of Mg is more preferably 0.001% or more.
  • the upper limit of the amount of Mg is preferably 0.01%.
  • the amount of Mg is more preferably 0.005% or less.
  • the steel plate of the present invention is a steel plate having no hydrogen cracking at the stage of the slab, or having a maximum horizontal hole thickness of the horizontal crack that is equal to or less than a threshold value.
  • the threshold means the maximum opening thickness of a horizontal crack that is obtained in advance and does not generate HIC in a steel plate obtained by rolling the slab.
  • microsegregation also exists between secondary dendrite trees. That is, microsegregation can also occur. However, since this secondary dendrite tree is very small and HIC does not propagate or extend, there is no problem in quality. Therefore, in the present invention, microsegregation is not considered.
  • Internal cracks include“ horizontal cracks ”and“ other internal cracks ”, which are caused by bulging between rolls, unbalanced cooling water, and deformation during correction.
  • the “horizontal crack” is a crack existing in the range of the slab thickness D / 2 from the width end portion in the width direction W of the slab, and propagated in the slab width direction and the casting direction. It is a crack.
  • the “other internal cracks” are cracks existing in the entire width of the slab and propagated in the slab thickness direction and the slab width direction, or in the slab thickness direction and the slab casting direction. It is a crack.
  • the degree of segregation of this “horizontal crack” is evaluated by “maximum aperture thickness” described below.
  • the occurrence position of the “horizontal crack” is as shown in FIG. 1A, and is a crack generated at the solid-liquid interface during solidification.
  • “Horizontal cracks” are accompanied by segregation lines formed by the intrusion of concentrated molten steel between dendritic trees. When this level is significant, holes are formed along the segregation lines. There is a correlation between the degree of segregation of horizontal cracks and the hole thickness (opening width), and the greater the hole thickness, the higher the degree of segregation of horizontal cracks. That is, there is a correlation between the maximum hole thickness and the degree of segregation of horizontal cracks.
  • HIC resistance can be judged by the “maximum aperture thickness”, and it has first been found that the HIC can be suppressed by reducing the maximum aperture thickness.
  • maximum hole thickness of the horizontal crack may be simply referred to as “maximum hole thickness”.
  • the present inventors can judge the HIC resistance of the steel plate after rolling by using the maximum hole thickness of the steel slab at the slab stage, that is, after casting and before rolling, the steel plate as a product will be obtained.
  • the present inventors have found that it is not necessary to perform an HIC test, the process can be omitted, and as a result, the product can be shipped early.
  • the slab obtained by casting is cut in the thickness direction, that is, in a direction perpendicular to the casting direction as shown in FIG. 2, and a horizontal crack in the segregated portion is investigated.
  • the position where the horizontal crack occurs is more likely to vary in the slab width direction and the slab thickness direction than in the casting direction. Therefore, as shown in FIG. 2 above, by using a cut surface perpendicular to the casting direction as an object to be investigated, it is possible to investigate a portion where the horizontal crack is most deteriorated.
  • the maximum aperture thickness t1 is the maximum aperture thickness in the region R1
  • the maximum aperture thickness t2 is the maximum aperture thickness in the region R2.
  • the regions R1 and R2 may be collectively referred to as a first range
  • the region R3 in FIG. 2 may be referred to as a second range.
  • the reason for investigating the areas R1 and R2 is as follows. That is, horizontal cracking occurs in the process in which solidification proceeds from both ends (narrow surfaces) in the width direction of the slab toward the center of the width. During solidification, the regions R1, R2, that is, the first range, are affected by cooling on the narrow surface side (short side), and solidification proceeds toward the center in the width direction. On the other hand, in the region R3 having a width WD excluding D / 2 from both ends in the width direction, that is, in the second range, solidification is not affected by the cooling on the narrow surface side (short side). Hardly progress. Accordingly, since horizontal cracks are considered to occur in the regions R1 and R2, in the present invention, as described above, horizontal cracks are investigated in the regions R1 and R2.
  • the maximum opening thickness among the plurality of opening thicknesses existing in each region R1 and R2 is set to the maximum opening thickness.
  • t1 and t2 For example, when there are three horizontal cracks in the region R1, the horizontal crack having the largest opening among the three horizontal cracks is selected, and the most open portion of the horizontal crack, that is, the hole thickness is the largest.
  • the opening thickness of the thick part is defined as “maximum opening thickness t1”.
  • the threshold value t ⁇ used for evaluating the HIC resistance of the slab that is, how to obtain the maximum hole thickness at which HIC does not occur in the steel plate obtained by rolling the slab will be described.
  • the threshold value t ⁇ is obtained in advance, but the method is not particularly limited. As a method for obtaining the threshold value t ⁇ , the following methods (i) to (iii) may be used in advance. Details will be described below.
  • (I) The maximum hole thickness of the slab is measured.
  • (Ii) An HIC test is performed on a steel plate obtained by rolling a slab cast under the same casting conditions as the slab.
  • (Iii) From the maximum opening thickness measured in (i) above and the HIC test result in (ii) above, the maximum opening thickness of horizontal cracks in which hydrogen-induced cracking does not occur is determined.
  • a slab cast under the same casting conditions as the slab whose maximum opening thickness was measured is hot-rolled to produce a steel plate for threshold measurement. Then, an HIC test is performed on the steel sheet to examine whether or not HIC is generated.
  • the HIC test can be performed by a method specified in NACE (National Association of OF Corrosion and Engineering) standard TM0284-2003, as shown in Examples described later.
  • the above “same casting conditions” are i) that casting speed is constant, ii) that there is no operational abnormality such as nozzle clogging, iii) that cooling conditions and roll gap are the same, etc. .
  • the threshold value t ⁇ is determined, the “degree of segregation obtained by investigating the slab” and the “HIC test result for the product” are associated with each other. However, if these HIC resistances are different, the threshold value cannot be determined.
  • the operating factors i) to iii) have a great influence on the horizontal cracking and center segregation, and thus also affect the HIC resistance. Accordingly, the resistance to HIC varies with the operation factor.
  • the steel plate obtained by manufacturing using the slab cast on the same casting conditions (operation factor) as the slab which investigated the maximum opening thickness for the steel plate for HIC tests it is preferable to use the steel plate obtained by manufacturing using the slab cast on the same casting conditions (operation factor) as the slab which investigated the maximum opening thickness for the steel plate for HIC tests.
  • the slab whose maximum opening thickness is investigated and the slab for the HIC test are the same.
  • HIC test it is checked whether HIC is generated in the product (steel plate) region corresponding to the slab regions R1 and R2 shown in FIG. Depending on the rolling direction during rolling using the slab shown in FIG. 2, the HIC resistance evaluation target area varies as shown in FIG. 3.
  • the slab width W the product width W.
  • the product regions corresponding to the “slab regions R1, R2” are “regions R11, R12 in the range of the product width D / 2 from both ends in the product width direction”.
  • the product region corresponding to “slab region R3” is “region R13 in the range of width WD excluding product width D / 2 from both ends in the product width direction”.
  • the width when the slab is rolled in the width direction, that is, when the width direction is included in the rolling direction, the width changes from W before rolling to Wa after rolling as shown in FIG. ⁇ Product width Wa.
  • the regions R21, R22, and R23 corresponding to the slab regions R1, R2, and R3 are determined by the rolling ratio, that is, the product width Wa / slab width W. Of these, it is confirmed whether or not HIC has occurred in the regions R21 and R22.
  • the “maximum opening thickness threshold t ⁇ ” at which no HIC is generated is determined.
  • the results obtained in the areas corresponding to each other are associated with each other between the slab and the product.
  • the product region R11 has “HIC generated” and the region R12 has “HIC not generated” as follows. .
  • I-1 As a result of the product region R11, “HIC is present” when the maximum opening thickness t1 of the slab region R1 (I-2)
  • I-2 As a result of the product region R12, “no HIC occurs” when the maximum opening thickness t2 of the slab region R2
  • the threshold value t ⁇ of the maximum hole thickness that becomes the boundary for the occurrence of HIC is determined.
  • the maximum hole thickness t2 is the threshold value t ⁇ .
  • the maximum aperture thickness t2 is the threshold value t ⁇ .
  • the measurement result of the horizontal cracking / maximum opening thickness of a plurality of slabs and the HIC test result for the determination of the threshold value t ⁇ .
  • the segregation part and HIC resistance investigation may be evaluated from one section of the slab or product, or may be evaluated from two or more sections.
  • FIG. 4 shows the result of examining a plurality of cross sections of the slab having the same charge.
  • Example 1 is an example in which two cross sections of the same charge are examined
  • Example 2 is an example in which three cross sections of the same charge are examined, and both are the results of conducting an investigation with a slab applicable to the APIX65 grade. is there.
  • Example 1 the maximum opening thickness was 0 mm in both of the two cross sections, and no HIC occurred from the horizontal crack in the HIC test.
  • Example 2 the maximum hole thickness of each of the three cross sections was 0.065 mm, 0.067 mm, and 0.066 mm, which were similar thicknesses. In all the cross sections, HIC occurred starting from the horizontal crack.
  • the slab applicable to the APIX65 grade was used, but the strength grade changed.
  • the formation and variation of internal cracks does not change, so the number of cross sections to be investigated is not limited.
  • the slab investigation position is preferably a stationary part as shown in the following examples, but may be an unsteady part.
  • the “unsteady portion” is a portion cast when a casting condition is changed, and includes a portion cast at an early stage of casting such as when the casting speed is increased, or a portion cast at the end of casting such as when the casting speed is decreased.
  • the steel plate of the present invention is a steel plate in which no horizontal cracks are present or the maximum opening thickness of the horizontal cracks is equal to or less than a threshold value t ⁇ at the stage of the slab before rolling.
  • a threshold value t ⁇ at the stage of the slab before rolling.
  • “maximum opening thickness of horizontal crack” is used for evaluation of HIC resistance. Since the internal quality of the slab can be accurately evaluated from this, the HIC resistance can be evaluated at the stage of the slab based on this evaluation result. Thereby, since the HIC test which requires several weeks can be omitted, the period from manufacture to shipment can be greatly shortened.
  • Table 1-1, Table 1-2, FIGS. 6 and 7 show experimental conditions and experimental results for determining the threshold value t ⁇ . Cast slabs equivalent to APIX65 grade and APIX70 grade each with 21 charges, slabs equivalent to ASMESA516 grade 60, ASME SA516 grade 65, and ASME70SA516 grade 70 respectively, and investigate horizontal cracking as follows did.
  • “X70” is API ⁇ X70 grade,“ X65 ”is API X65 grade,“ SA516560 ”is ASME SA516 grade 60,“ SA516 ⁇ 65”.
  • ASME SA516 grade 65” and “SA516 70” denotes ASME SA516 grade 70.
  • the slab was cut at the stationary part at a total length of 10 to 15 m, and the horizontal crack was examined as follows.
  • the “stationary part” is a part that satisfies the following conditions.
  • Table 1-1 and Table 1-2 show the number of cross sections for horizontal crack investigation. 1) The casting speed is constant. 2) No abnormal operation such as clogged immersion nozzle has occurred. 3) Cooling conditions have not changed. 4) The roll gap has not changed.
  • Cmax (Mn) The Mn segregation degree of this horizontal crack portion is indicated by Cmax (Mn).
  • Cmax (Mn) / C 0 (Mn) was calculated from the Mn concentration of the molten steel in the tundish measured during casting, that is, C 0 (Mn) and the Cmax (Mn).
  • C 0 (Mn) and the Cmax (Mn) Horizontal cracks in the part subjected to EPMA analysis were observed with a microscope (20 to 50 times), and the thickness of the aperture was measured.
  • the steel plate surface temperature is 900 ° C or higher, and the average steel plate temperature calculated by the following calculation is 1000 ° C or higher.
  • Hot rolling is performed so that a pass having a rate of 40% or more and a reduction rate per pass of 10% or more becomes 2 passes or more. Thereafter, hot rolling was performed so that the cumulative rolling reduction at 700 ° C. or more and less than 900 ° C. was 20% or more, so that the rolling end temperature was 700 ° C. or more and less than 900 ° C. Thereafter, water cooling was started from a temperature of 650 ° C.
  • slabs equivalent to ASME SA516 grade 60, ASME SA516 grade 65 and ASME SA516 grade 70 were hot-rolled so that the rolling end temperature was 850 ° C. or higher, then air-cooled to room temperature, and further 850 ° C. After reheating to a temperature of 950 ° C. or lower and quenching, tempering was performed at 600 to 700 ° C. to obtain a steel plate having a thickness of 40 mm. In all cases, rolling was not performed in the slab width direction.
  • the above steel plate average temperature is obtained as follows. That is, based on data such as a rolling pass schedule during rolling and a cooling method (water cooling or air cooling) between passes, the temperature at an arbitrary position in the plate thickness direction is calculated using a method suitable for calculation such as a difference method, Let the average value of the temperature from the surface of the calculated
  • HIC test In order to determine the threshold value t ⁇ , in this example, an HIC test was performed after rolling.
  • a sample was cut out from the rolled product and an HIC test was performed. The HIC test was performed according to the method specified in NACE standard TM0284-2003.
  • B After the HIC test, the sample was cut at three locations, and each cross section (three cross sections) was observed with a microscope to confirm the presence or absence of HIC. Here, the presence or absence of cracks was confirmed in “regions R11 and R12 in the range of D / 2 from both ends in the width direction of the product” shown in FIG.
  • FIGS. 6 and 7 show the relationship between ““ horizontal crack opening thickness ”and“ Cmax (Mn) / C 0 (Mn) ”” and “presence or absence of HIC generation” confirmed by the HIC test.
  • FIG. 6 is a result of investigating a threshold value t ⁇ at which HIC occurs in components having strength classes shown in Table 1-2 equivalent to APIX65 grade, ASME SA516 grade 60 equivalent, and ASME SA516 grade 65
  • FIG. -1 and Table 1-2 are the results of investigating the threshold value t ⁇ at which HIC occurs in components corresponding to APIX70 grade and ASME SA516 grade70.
  • the threshold t ⁇ of the maximum opening thickness was set to 0.047 mm, and the determination was made as follows. When the maximum aperture thickness ⁇ 0.047 mm, it is determined that no HIC occurs. It is determined that HIC occurs when the maximum hole thickness> 0.047 mm.
  • ASMESA516 grade 60, grade 65, and ASTM A516 grade 60, grade 65 are components equivalent to APIX65 grade, and therefore the threshold t ⁇ of the maximum opening thickness was set to 0.047 mm, and the following judgment was made.
  • the maximum aperture thickness ⁇ 0.047 mm it is determined that no HIC occurs. It is determined that HIC occurs when the maximum hole thickness> 0.047 mm.
  • the threshold t ⁇ of the maximum opening thickness was set to 0.043 mm, and the determination was made as follows. When the maximum hole thickness ⁇ 0.043 mm, it is determined that no HIC occurs. It is determined that HIC is generated when the maximum hole thickness> 0.043 mm.
  • ASMESA516 grade 70 and ASTM A516 grade 70 are components equivalent to APIX70 grade
  • the threshold t ⁇ of the maximum opening thickness was set to 0.043 mm, and the determination was made as follows. When the maximum hole thickness ⁇ 0.043 mm, it is determined that no HIC occurs. It is determined that HIC is generated when the maximum hole thickness> 0.043 mm.
  • the HIC resistance of the judgment target slab was evaluated by the following procedure using the threshold value t ⁇ .
  • steel having the component composition shown in Table 2 was melted, and a slab to be determined having a slab thickness D of 280 mm and a slab width W of 2100 mm was obtained by continuous casting. And it evaluated in the following procedure using this slab.
  • a range of width D / 2 from both ends in the width direction of the slab cut surface to be judged was milled, and a dye penetration test (JIS Z2343) was performed.
  • JIS Z2343 dye penetration test
  • the maximum aperture thickness was not more than the threshold value t ⁇ , that is, 0.047 mm or less for the APIX65 grade and 0.043 mm or less for the APIX70 grade, so it was determined that no HIC due to horizontal cracking occurred.
  • TMCP TMCP
  • QT “Hot rolling / cooling method” column of Table 3
  • steel sheets having various component compositions (9 to 90 mm plate thickness ⁇ 2000 to 3500 mm width ⁇ 12000 to 35000 mm length) were obtained.
  • the “TMCP” is a steel sheet surface temperature of 900 ° C. or higher, an average steel plate temperature calculated by calculation of 1000 ° C. or higher, a cumulative rolling reduction of 40% or higher, and a rolling reduction per pass of 10% or higher.
  • Hot rolling was performed so that a given pass was 2 passes or more. Thereafter, hot rolling is performed so that the cumulative rolling reduction of 700 ° C.
  • the rolling end surface temperature is set to 850 ° C.
  • the cooling start surface temperature average cooling from 950 ° C.
  • Speed Cooling is started at 10 ° C./s, stopped at a temperature of 350 to 600 ° C., and then cooled to room temperature.
  • the “QT” is hot-rolled so that the rolling end temperature is 850 ° C. or higher, air-cooled to room temperature, reheated to a temperature of 850 ° C. or higher and 950 ° C. or lower, quenched, and then baked at 600 to 700 ° C. This is a method of performing a return process.
  • HIC test The HIC test was implemented using the said steel plate.
  • the HIC test was performed according to the method specified in NACE standard TM0284-2003. After the HIC test, the sample was cut at three locations, and each cross section (three cross sections) was observed with a microscope to confirm the presence or absence of HIC. The results are shown in Table 3.
  • Table 2 and Table 3 show the following. No. Nos. 1 to 7, 10, 12, and 14 to 17 satisfy the specified composition, and the maximum open hole thickness of the horizontal crack of the slab is suppressed to a threshold value t ⁇ or less, and the steel plate of the present invention having excellent HIC resistance It is.
  • No. Nos. 11 and 13 the maximum opening thickness of the horizontal crack of the slab exceeded the threshold value t ⁇ , and thus the HIC resistance evaluation of the slab was NG. Further, in the HIC test performed after rolling, it was confirmed that the steel plate was cracked and inferior in HIC resistance.
  • No. Nos. 8, 9, 18 and 19 are examples in which the chemical composition of the steel sheet deviates from the definition of the present invention, although the maximum hole thickness of the horizontal crack of the slab is suppressed to a threshold value t ⁇ or less. That is, the steel plate of No. 8 has REM and Zr of 0%, and the value of (Ca / S) is out of regulation, the steel plate of No.
  • the period from casting start to shipment of the product steel plate, that is, the sour steel plate (casting ⁇ rolling ⁇ shipping) was 19 days.
  • the period from casting start to shipping is as long as 28 days. It took a period.
  • the period from the start of casting to shipment could be greatly shortened from 28 days to 19 days.
  • the period from the start of casting to the shipment of the product steel plate, that is, the sour steel plate (casting ⁇ Remelting ⁇ rolling ⁇ shipping) was 54 days.
  • the evaluation is NG
  • remelting was started after the HIC test was performed.
  • the period from the start of casting to the shipment of the steel sheet as a product (casting ⁇ rolling ⁇ HIC test ⁇ remelting ⁇ rolling ⁇ HIC test ⁇ shipping) required 72 days.
  • the HIC test after rolling could be omitted, even when remelting was necessary, the period from the start of casting to shipment could be greatly shortened from 72 days to 54 days.
  • the determination method of the present invention is highly accurate because the HIC test for determining the threshold t ⁇ for evaluating the HIC resistance of the slab and the HIC test for confirmation are the same.

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  • Engineering & Computer Science (AREA)
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  • Heat Treatment Of Steel (AREA)

Abstract

Cette invention concerne une tôle d'acier et un tube acier qui présentent une excellente résistance à la fissuration induite par l'hydrogène. L'invention concerne en outre une tôle d'acier et un tube d'acier dont la résistance à la fissuration induite par l'hydrogène (HIC) peut être évaluée à partir de la qualité interne d'une pièce coulée, sans effectuer d'essais HIC. Ladite tôle d'acier présentant une excellente résistance à la fissuration induite par l'hydrogène satisfait à des teneurs prescrites en C, Si, Mn, P, S, Al, Ca, N, et O et elle comprend au moins un élément choisi dans le groupe constitué d'un matériau de terres rares déterminé et du Zr, le reste étant du fer et les inévitables impuretés. Ladite tôle d'acier est caractérisée en ce que : le rapport Ca et S (Ca/S) est supérieur ou égal à 2,0 ; Ca, S, et O satisfont à (Ca - 1,25S)/O ≤ 1,80 ; et elle ne présente pas de fissuration horizontale à l'état de brame ou l'épaisseur d'ouverture maximale de fissuration horizontale n'est pas supérieure à un seuil tθ et le seuil tθ est l'ouverture maximale de fissuration horizontale à laquelle la fissuration induite par l'hydrogène ne se produit pas dans une tôle d'acier obtenue par laminage de la brame.
PCT/JP2015/085870 2014-12-26 2015-12-22 Tôle d'acier présentant une excellente résistance à la fissuration induite par l'hydrogène et tube d'acier pour tube de canalisation WO2016104527A1 (fr)

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KR1020177019243A KR20170093965A (ko) 2014-12-26 2015-12-22 내수소유기균열성이 우수한 강판 및 라인 파이프용 강관
CN201580069985.6A CN107109565A (zh) 2014-12-26 2015-12-22 抗氢致裂纹性优异的钢板和管线管用钢管
KR1020197035849A KR102141794B1 (ko) 2014-12-26 2015-12-22 내수소유기균열성이 우수한 강판 및 라인 파이프용 강관
EP15873095.2A EP3239320B1 (fr) 2014-12-26 2015-12-22 Tôle d'acier et tube d'acier pour tube de canalisation présentant une excellente résistance à la fissuration induite par l'hydrogène

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JP2015207452A JP6584912B2 (ja) 2014-12-26 2015-10-21 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

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7332078B1 (ja) 2022-06-03 2023-08-23 Ｊｆｅスチール株式会社 サワーガス設備用高強度鋼板及びそれを用いた高強度鋼管
WO2023233734A1 (fr) * 2022-06-03 2023-12-07 Ｊｆｅスチール株式会社 Tôle d'acier à haute résistance pour installation de gaz acide, et tuyau en acier à haute résistance l'utilisant

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012036462A (ja) * 2010-08-09 2012-02-23 Nippon Steel Corp 耐水素誘起割れ性に優れた鋼材
WO2013147197A1 (fr) * 2012-03-30 2013-10-03 新日鐵住金株式会社 Tuyau d'acier à haute résistance pour tuyau de canalisation ayant une excellente résistance à la fissuration induite par hydrogène, tuyau d'acier à haute résistance pour tuyau de canalisation l'utilisant et son procédé de fabrication
JP2013213242A (ja) * 2012-03-30 2013-10-17 Kobe Steel Ltd 耐水素誘起割れ性に優れた鋼板およびその製造方法
JP2013237101A (ja) * 2012-04-20 2013-11-28 Kobe Steel Ltd 耐水素誘起割れ性に優れた鋼材およびその製造方法
JP2014214371A (ja) * 2013-04-30 2014-11-17 株式会社神戸製鋼所 耐サワー性とｈａｚ靭性に優れた鋼板

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012036462A (ja) * 2010-08-09 2012-02-23 Nippon Steel Corp 耐水素誘起割れ性に優れた鋼材
WO2013147197A1 (fr) * 2012-03-30 2013-10-03 新日鐵住金株式会社 Tuyau d'acier à haute résistance pour tuyau de canalisation ayant une excellente résistance à la fissuration induite par hydrogène, tuyau d'acier à haute résistance pour tuyau de canalisation l'utilisant et son procédé de fabrication
JP2013213242A (ja) * 2012-03-30 2013-10-17 Kobe Steel Ltd 耐水素誘起割れ性に優れた鋼板およびその製造方法
JP2013237101A (ja) * 2012-04-20 2013-11-28 Kobe Steel Ltd 耐水素誘起割れ性に優れた鋼材およびその製造方法
JP2014214371A (ja) * 2013-04-30 2014-11-17 株式会社神戸製鋼所 耐サワー性とｈａｚ靭性に優れた鋼板

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7332078B1 (ja) 2022-06-03 2023-08-23 Ｊｆｅスチール株式会社 サワーガス設備用高強度鋼板及びそれを用いた高強度鋼管
WO2023233734A1 (fr) * 2022-06-03 2023-12-07 Ｊｆｅスチール株式会社 Tôle d'acier à haute résistance pour installation de gaz acide, et tuyau en acier à haute résistance l'utilisant

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