WO2018169020A1 - H形鋼およびその製造方法 - Google Patents
H形鋼およびその製造方法 Download PDFInfo
- Publication number
- WO2018169020A1 WO2018169020A1 PCT/JP2018/010339 JP2018010339W WO2018169020A1 WO 2018169020 A1 WO2018169020 A1 WO 2018169020A1 JP 2018010339 W JP2018010339 W JP 2018010339W WO 2018169020 A1 WO2018169020 A1 WO 2018169020A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- flange
- width direction
- thickness
- rolling
- steel
- Prior art date
Links
Images
Classifications
-
- 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
-
- 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
- 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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- C—CHEMISTRY; METALLURGY
- 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
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C3/00—Structural elongated elements designed for load-supporting
- E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
- E04C3/04—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C3/00—Structural elongated elements designed for load-supporting
- E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
- E04C3/04—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal
- E04C3/06—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal with substantially solid, i.e. unapertured, web
-
- 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
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C3/00—Structural elongated elements designed for load-supporting
- E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
- E04C3/04—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal
- E04C2003/0404—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal beams, girders, or joists characterised by cross-sectional aspects
- E04C2003/0443—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal beams, girders, or joists characterised by cross-sectional aspects characterised by substantial shape of the cross-section
- E04C2003/0452—H- or I-shaped
Definitions
- the present disclosure relates to an H-section steel and a manufacturing method thereof.
- Patent Document 1 a technique for obtaining a steel material with good toughness after securing strength by applying accelerated cooling for the production of H-section steel has been proposed.
- Patent Document 2 a technique has been proposed in which accelerated cooling is applied to ensure a high strength of 590 MPa class and toughness at 0 ° C.
- Patent Document 3 a technique for securing high strength and toughness at 0 ° C. by applying accelerated cooling has been proposed.
- Patent Document 4 A technique for obtaining the above has been proposed (Patent Document 4).
- Patent Document 5 A method has been proposed in which steel pieces to which Cu, Ni, Cr, Mo, and B are added are hot-rolled and then allowed to cool to ensure uniform mechanical properties.
- Patent Document 6 A technology has been proposed in which a steel material having a predetermined chemical composition is heated, the flange and the web are rolled under specific conditions, the flange is accelerated and cooled at a cooling rate of 1 ° C / s or higher, and the web is allowed to cool.
- Patent Document 7 A technique has been proposed in which a microstructure based on a 1 ⁇ 4 flange portion satisfies a specific condition in a cross section of an H-section steel manufactured from a steel piece having a chemical component having a specific carbon equivalent (Patent Document 7). ).
- Patent Document 1 Japanese Patent Application Laid-Open No. 2003-328070
- Patent Document 2 Japanese Patent Application Laid-Open No. 2006-32219
- Patent Document 3 Japanese Patent Application Laid-Open No. 11-335735
- Patent Document 4 Japanese Patent Application Laid-Open No. 2016-141834
- Patent Document 5 Japanese Patent Application Laid-Open No. 8-197103
- Patent Document 6 Japanese Patent Application Publication No. 2006-249475
- Patent Document 7 International Publication No. 2001-075182
- H-section steel with a flange thickness of 25 mm or more (hereinafter sometimes referred to as extra-thick H-section steel) is desired.
- shape of H-section steel is unique, and rolling conditions (temperature, rolling reduction) are limited in universal rolling. For this reason, particularly when producing an extremely thick H-shaped steel, the difference in mechanical properties in each part such as a web, a flange, and a fillet may be larger than that of a thick steel plate.
- Patent Document 5 For such a problem, a technique disclosed in Patent Document 5 has been proposed.
- the present disclosure has been made in view of such circumstances, and an object thereof is to provide an H-section steel excellent in strength and low-temperature toughness, and a manufacturing method thereof.
- Means for solving the above problems include the following aspects.
- the carbon equivalent Ceq obtained by the following formula (1) is 0.300 to 0.480,
- the flange thickness is 25-140mm, The widthwise length of the flange F, if the thickness
- a method for producing the H-section steel according to (1) Heating the steel slab having the composition described in (1) to 1100 to 1350 ° C .; Rolling is started after the heating, and the cumulative rolling reduction A at a surface temperature of 900 ° C. or more and 1100 ° C. or less is more than 10% at a position of (1/6) F from the width direction end face of the flange in the width direction of the flange. Rolling, rolling at a cumulative reduction ratio B of less than 900 ° C. and 750 ° C. or more at 10% or more, finishing the rolling with a surface temperature of 750 ° C.
- the flange width direction is (1/6) F from the end surface in the width direction of the flange and the thickness of the flange Accelerated cooling with an average cooling rate of 0.4 ° C./s or more, continuously or in between with air cooling at a position of (1/4) t 2 from the outer surface in the thickness direction of the flange.
- An intermittent process The manufacturing method of the H-section steel which has this.
- the accelerated cooling is accelerated cooling in the width direction of the flange until the recuperated temperature after cooling stop becomes 600 ° C. or less at a position of (1/6) F from the end surface in the width direction of the flange.
- the accelerated cooling is accelerated cooling in the width direction of the flange until the recuperated temperature after cooling stop becomes 600 ° C. or less at a position of (1/6) F from the end surface in the width direction of the flange.
- an H-section steel excellent in strength and low-temperature toughness, and a manufacturing method thereof are provided.
- a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
- a numerical range in which “exceeding” or “less than” is added to the numerical values described before and after “to” means a range not including these numerical values as the lower limit value or the upper limit value.
- “%” indicating the content of a component (element) means “% by mass”.
- the term “process” is not limited to an independent process, but is used in this term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. included.
- the H-section steel of the present disclosure has a component composition described later and has a carbon equivalent described later.
- the thickness of the flange is 25 to 140 mm. Further, the widthwise length of the flange F, if the thickness and t 2, the width direction of the flange, the widthwise end face of the flange (1/6) a position of the F, and, in a thickness direction of the flange
- the ferrite crystal grain size on the plane orthogonal to the width direction of the flange is 38 ⁇ m or less, with the position at (1/4) t 2 from the outer surface in the thickness direction of the flange as the center of the measurement position.
- the area fraction of the martensite-austenite mixed structure (MA) in the steel structure in the plane perpendicular to the width direction of the flange centered on the measurement position is 1.2% or less.
- the 0.2% proof stress is 385 MPa or more, and the tensile strength is 490 MPa or more.
- the absorbed energy of the Charpy test at ⁇ 20 ° C. at the measurement position is 200 J or more.
- the present inventors have examined the influence of the composition and the metal structure on the strength and toughness inside the flange of an extremely thick H-section steel (hereinafter sometimes referred to as a steel material). Obtained knowledge.
- the inventors of the present invention are effective when Cu, Ni, Cr, Nb and V are contained. I found out that there was. Cu, Ni, Cr, and Nb achieve high strength through improved hardenability, and Nb and V increase the strength of steel through precipitation strengthening. Further, by containing Nb, through an increase in strain in the steel material due to rolling in the non-recrystallization temperature range, it contributes to refinement of the steel material structure after accelerated cooling and improves toughness.
- the cumulative reduction ratio (cumulative reduction ratio A) exceeds 10% in a temperature range of 900 ° C. or higher and 1100 ° C. or lower is performed, and in a temperature range of less than 900 ° C. and 750 ° C. or higher, the cumulative reduction ratio ( Hot rolling with a cumulative rolling reduction B) of 10% or more is performed.
- the above-mentioned average crystal grain size can be realized by performing the hot rolling. This is because the austenite grains become finer in the temperature range of 900 ° C. or higher, so that the toughness can be improved by refining the steel structure after accelerated cooling.
- miniaturization of the steel structure after accelerated cooling is realizable by providing many distortions in steel materials.
- the present inventor has also revealed that it is preferable to set the cooling rate of accelerated cooling to 2.0 ° C./s or less on average.
- the upper limit of the average cooling rate of accelerated cooling is not particularly limited. It is an example of preferable conditions that the cooling rate of accelerated cooling is 2.0 ° C./s or less on average.
- this accelerated cooling is preferably performed for as long as possible. Specifically, it is preferable to carry out until the recuperation temperature after the stop of the accelerated cooling becomes 600 ° C. or less. Accelerated cooling may be performed continuously to the target temperature, or intermittent cooling may be performed by providing one or more times of air cooling during accelerated cooling.
- the position in the width direction of the flange is (1/6) F from the end surface in the width direction of the flange.
- it is effective to set the average cooling rate to 0.4 ° C./s or more at a position of (1/4) t 2 from the outer surface in the thickness direction of the flange in the thickness direction of the flange.
- C (C: 0.040 to 0.100%) C is an element effective for strengthening steel, and in the H-section steel of the present disclosure, the lower limit value of the C content is 0.040%. A preferable lower limit of the C content is 0.050%. On the other hand, if the C content exceeds 0.100%, the amount of cementite and MA produced becomes excessive, leading to a decrease in toughness. Therefore, the upper limit of the C content is set to 0.100%. The upper limit with preferable C content is 0.080%.
- the lower limit of the Mn content is set to 0.50% in the H-section steel of the present disclosure. In order to further increase the strength, it is preferable to set the lower limit of the Mn content to 1.00%. On the other hand, if the Mn content exceeds 1.70%, the hardenability is excessively increased, and the formation of MA is promoted to impair toughness. Therefore, the upper limit of the Mn content is 1.70%. The upper limit with preferable Mn content is 1.60%.
- Cu 0.01 to 0.50%
- Cu improves hardenability and contributes to improvement of tensile strength.
- the Cu content is set to 0.01% or more.
- a preferable lower limit of the Cu content is 0.10%.
- the upper limit of the Cu content is 0.50%.
- the upper limit with preferable Cu content is 0.30%.
- Ni is an element that improves the hardenability by forming a solid solution in steel, and contributes to the improvement of tensile strength.
- the Ni content is set to 0.01% or more.
- a preferable lower limit of the Ni content is 0.10%.
- the upper limit of the Ni content is 0.50%.
- the upper limit with preferable Ni content is 0.30%.
- Cr 0.01 to 0.50%
- Cr is an element that contributes to improvement of tensile strength by increasing hardenability.
- the Cr content is set to 0.01% or more.
- a preferable lower limit of the Cr content is 0.05%.
- the upper limit of the Cr content is 0.50%.
- the upper limit with preferable Cr content is 0.30%.
- Nb suppresses recrystallization of austenite during hot rolling, contributes to finer ferrite and bainite by accumulating processing strain in the steel, and further contributes to strength improvement by precipitation strengthening To do.
- the Nb content is set to 0.001% or more.
- a preferable lower limit of the Nb content is 0.010%.
- the upper limit of Nb content is 0.050%.
- the upper limit with preferable Nb content is 0.040%.
- V forms carbonitrides and contributes to precipitation strengthening. Furthermore, V carbonitrides precipitated in the austenite grains act as ferrite and bainite transformation nuclei, and also have the effect of refining ferrite and bainite crystal grains. In order to obtain these effects, the V content is set to 0.010% or more. The minimum with preferable V content is 0.030%, and a more preferable minimum is 0.050%. However, when V is contained excessively, toughness may be impaired due to coarsening of precipitates. Therefore, the upper limit of V content is 0.120%. The upper limit with preferable V content is 0.100%.
- Al acts as a deoxidizing element in the H-section steel of the present disclosure.
- the Al content is set to 0.005% or more.
- the upper limit of the Al content is set to 0.100%.
- Ti is an element that forms TiN and fixes N in the steel.
- the lower limit of the Ti content is set to 0.001%.
- TiN has an effect of refining austenite by a pinning effect. Therefore, the preferable lower limit of the Ti content is 0.007%.
- the upper limit of the Ti content is 0.025%.
- the upper limit with preferable Ti content is 0.020%.
- B is an element that increases the hardenability and brings about an increase in strength of the steel material.
- the lower limit of the B content is set to more than 0.0005%.
- a preferable lower limit of the B content is 0.0006%.
- the upper limit of the B content is set to 0.0020%.
- the upper limit with preferable B content is 0.0015%.
- N is an element that forms TiN and VN and contributes to the refinement of the structure and precipitation strengthening. Therefore, the lower limit of the N content may be 0.0001% and 0.0010% may be the lower limit. However, when the N content is excessive, the toughness of the base material is lowered, which causes a material defect due to surface cracking during casting and strain aging of the manufactured steel material. Therefore, the upper limit of N content is 0.0120%. Preferably, the preferable upper limit of N content is 0.0080%.
- P, S, and O are impurities, and their content is not particularly limited. However, since P and S cause weld cracking due to solidification segregation and a decrease in toughness, the content of P and S is preferably reduced.
- the upper limit of the P content is preferably limited to 0.03%.
- the upper limit with more preferable P content is 0.01%.
- limit the upper limit of S content is 0.02%.
- the lower limit of P content and S content is not specifically limited, It may exceed 0%. For example, it may be 0.0001% or more from the viewpoints of dephosphorization cost reduction and desulfurization cost reduction.
- the upper limit of the O content is preferably 0.0050%.
- a more preferable upper limit of the O content is 0.0030%.
- the lower limit value of the O content is not particularly limited, but may be over 0% or 0.0001% or more.
- Si may be contained.
- Mo, W, Ca, Zr, Mg, and REM may be included. These elements may or may not be contained. Therefore, the lower limit of these elements is 0%.
- Si is a deoxidizing element and contributes to the improvement of strength.
- the upper limit of the Si content is 0.08%.
- the upper limit with preferable Si content is 0.05%.
- the lower limit of the Si content is not particularly limited.
- the lower limit of the Si content may be greater than 0% or 0.01%.
- Mo 0 to 0.20%
- Mo is an element that improves the hardenability by dissolving in steel.
- the Mo content is preferably 0.01% or more, and more preferably 0.05% or more.
- the upper limit of the Mo content is 0.20%.
- W is an element that improves the hardenability by dissolving in steel.
- the W content is preferably 0.01% or more, and more preferably 0.10% or more.
- the upper limit of W content is 0.50%.
- Ca is an element effective for controlling the form of sulfide, suppresses the formation of coarse MnS, and contributes to the improvement of toughness.
- the Ca content is preferably 0.0001% or more, and more preferably 0.0010% or more.
- the upper limit of Ca content is 0.0050%.
- the upper limit with more preferable Ca content is 0.0030%.
- Zr 0 to 0.0050% Zr precipitates as carbides and nitrides and contributes to precipitation strengthening of steel.
- the Zr content is preferably 0.0001% or more, and more preferably 0.0010% or more.
- the carbide and nitride of Zr may be coarsened and the toughness may be lowered. Therefore, the upper limit of the Zr content is 0.0050%.
- Mg and REM rare earth elements; that is, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, etc. are used for the purpose of improving the base metal toughness and the welded HAZ toughness. It may contain at least one element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. The lower limit of these elements is 0%. However, when these elements are contained excessively, the effect of improving the base metal toughness and the welded HAZ toughness cannot be obtained.
- the lower limit of the Mg content is preferably 0.0001%.
- the upper limit of the Mg content is 0.0050% or less.
- the upper limit with preferable Mg content is 0.0032%.
- the minimum of REM content shall be 0.001%.
- the upper limit of the REM content is 0.005% or less.
- the upper limit with preferable REM content is 0.003%.
- the balance consists of Fe and impurities.
- the impurity refers to a component contained in the raw material or a component mixed in the manufacturing process and not intentionally contained in the steel.
- the carbon equivalent Ceq obtained by the following formula (1) is specified in the range of 0.300 to 0.480 from the viewpoint of securing the tensile strength. If Ceq is less than 0.300, the hardenability becomes insufficient and the tensile strength becomes insufficient. Preferably, the lower limit of Ceq is set to 0.350. On the other hand, when Ceq exceeds 0.480, the hardenability increases excessively, the strength becomes excessive, and the toughness decreases. Preferably, the upper limit of Ceq is 0.450.
- Ceq is an index of hardenability (carbon equivalent), and is obtained by the following formula (1).
- C, Mn, Cr, Mo, V, Ni, and Cu represent the content (mass%) of each element in steel. Elements not contained are set to 0.
- C, Mn, Cr, Mo, V, Ni, and Cu represent the content (% by mass) of each element. When it is not contained, 0 is set. That is, in Formula (1), when H-section steel contains the element of C, Mn, Cr, Mo, V, Ni, and Cu, the content (mass%) of each element to contain is substituted. If there is an element not contained, 0 is substituted.
- a portion including the measurement position 7 shown in FIG. 1 is taken as a test piece as a position where average toughness is obtained, and an average crystal grain size, an area fraction of MA, and toughness are obtained. To evaluate.
- FIG. 1 is a schematic cross-sectional view orthogonal to the rolling direction of the H-section steel 4.
- the H-shaped steel 4 is composed of a pair of plate-like flanges 5 facing each other, and a plate-like web 6 provided so as to be orthogonal to the flanges 5 and to connect the centers in the width direction of the opposed surfaces of the flanges 5. Is provided.
- the X-axis direction is defined as the width direction of the flange 5
- the Y-axis direction is defined as the thickness direction of the flange 5
- the Z-axis direction is defined as the rolling direction (length direction of the flange 5).
- the widthwise length of the flange 5 and F when the thickness of the flange 5 and t 2, the widthwise end face 5a of the flange 5 (1/6) position of F (in Figure 1, a F / 6 hereinafter), and the thickness direction outer surface 5b of the flange 5 (1/4) position of t 2 (in FIG. 1, a measurement position 7 to t 2/4 the drawing) .
- the surface orthogonal to the width direction of the flange 5 centering on the measurement position 7 is a surface for measuring the average crystal grain size and the area fraction of MA.
- the flange 5 along either one place of the measurement position 7 A cross section perpendicular to the width direction (X direction) is taken as a measurement surface. Then, the average crystal grain size is measured in a 1 mm square region centering on the measurement position 7 along the rolling direction of the section, and the MA area fraction is measured in a 500 ⁇ m square region.
- the average crystal grain size is a cross section at a position 1 ⁇ 4 from the tip in the rolling direction (Z direction) of the H-section steel at any one of the four measurement positions 7 on the top, bottom, left, and right of the flange 5. Measure with.
- the surface 5b on the outer side in the thickness direction of the flange 5 is one surface in the thickness direction of the flange 5 and is the surface not in contact with the web 6, and is an end surface indicated by reference numeral 5b shown in FIG. It is. Moreover, the width direction end surface 5a of the flange 5 is an end surface which the code
- the crystal grain size in the steel material structure can be discriminated by observation by EBSD (electron beam backscatter diffraction method).
- the crystal grain size is a circle-equivalent diameter.
- EBSD electron beam backscatter diffraction method
- the average crystal grain size is calculated for all the metal structures included in the grain boundary (hereinafter simply referred to as the average crystal grain size).
- the average crystal grain size is a weighted average calculated by weighting each crystal grain size by the area of the crystal grain.
- the average crystal grain size in the steel structure is set to 38 ⁇ m or less.
- the toughness decreases.
- the condition of the average crystal grain size is an important factor for ensuring toughness at ⁇ 20 ° C. in a steel having a tensile strength of 490 MPa or more, which is a target for the H-shaped steel of the present disclosure. This has been clarified through experiments.
- the lower limit of the average crystal grain size is not particularly limited.
- the lower limit of the average crystal grain size may be 5 ⁇ m, for example, in terms of manufacturability.
- the area fraction of MA in the steel structure can be measured by observing an observation sample collected from the steel with a repeller reagent, observing it with an optical microscope, and extracting the MA with known image analysis software. . Specifically, in a sample for observation corroded with a repeller reagent, a 500 ⁇ m square surface perpendicular to the width direction of the flange 5 with the steel measurement position 7 as the center is photographed with an optical microscope at 200 times. Then, for the photographed image, MA is extracted by image analysis software “Image-Pro”, and the area fraction of the MA is measured.
- the area fraction of MA is a cross section at a position 1 ⁇ 4 from the tip in the rolling direction of the H-section steel (Z direction) at any one of the four measurement positions 7 on the top, bottom, left, and right of the flange 5. Measure with.
- the area fraction of MA in the steel structure is set to 1.2% or less.
- the area fraction of MA is an important factor for ensuring toughness at ⁇ 20 ° C. in a steel having a tensile strength of 490 MPa or more, which is a target for the H-shaped steel of the present disclosure. This has been clarified through experiments. It is preferable that the area fraction of MA is small in terms of suppressing toughness reduction.
- the area fraction of MA is preferably 1.0% or less, and more preferably 0.8% or less.
- the area fraction of MA may be 0%.
- the metal structure of the steel material is pearlite 0 to 10% and MA 0 to 1.2% in terms of securing toughness at the measurement position 7, and the remaining balance is ferrite (polygonal). Ferrite), bainite, and acicular ferrite.
- the balance is preferably made of ferrite (polygonal ferrite) and at least one of bainite and acicular ferrite in terms of securing strength and low temperature toughness.
- the area fraction of ferrite (polygonal ferrite) in the balance is not particularly limited, and may be, for example, 10 to 90%.
- the test piece 9 at the time of evaluating toughness by the Charpy test can be exemplified by a rectangular parallelepiped sampled such that the measurement position 7 is the center of the cross section in the rolling direction and the longitudinal direction is parallel to the rolling direction.
- the surface on which the notch is formed in the test piece 9 is one of the surfaces parallel to the end surface 5a in the width direction of the flange 5 (the surfaces 11 and 13 shown in FIG. 2).
- the test piece 9 may be collected from any position in the rolling direction as long as the measurement position 7 is the center in the width direction of the test piece (the center in the X-axis direction shown in FIG. 2).
- the notch direction is the width direction of the flange 5 (X-axis direction shown in FIG. 2).
- test piece at the time of evaluating yield strength or 0.2% yield strength by a tensile test will be described.
- a test piece for evaluating yield strength or 0.2% yield strength by a tensile test is shown in FIG. 1 from the width direction end face 5a of the flange 5 toward the width direction of the flange 5 (X-axis direction shown in FIG. 1).
- the test piece was cut out with the (1/6) F position as the center in the width direction of the test piece.
- a tensile test is performed.
- the longitudinal direction of the test piece is parallel to the rolling direction (Z-axis direction shown in FIG.
- test piece 1 1), and from the entire thickness direction (the total thickness) of the thickness direction of the flange 5 (Y-axis direction shown in FIG. 1). Cut it out.
- the thickness in the width direction of the test piece is in the range specified in JIS Z 2241 (2011). It should be noted that the test piece has any position in the rolling direction as long as the position of (1/6) F is the center in the width direction of the test piece from the end surface 5a of the flange 5 in the width direction of the flange 5. May be taken from
- the thickness t 2 of the flange 5 of the H-section steel 4 of the present disclosure is 25 to 140 mm.
- the reason why the lower limit of the thickness t 2 is set to 25 mm is that, for example, a strength member having a thickness t 2 of the flange 5 of 25 mm or more is required for the H-section steel 4 used in a high-rise building structure.
- a preferable lower limit of the thickness t 2 of the flange 5 is 40 mm.
- the reason why the upper limit of the thickness t 2 of the flange 5 is 140 mm is that when the thickness t 2 of the flange 5 exceeds 140 mm, the amount of hot working is insufficient and it is difficult to achieve both strength and toughness.
- a preferable upper limit of the thickness t 2 of the flange 5 of the H-section steel 4 is 125 mm. Therefore, the thickness t 2 of the flange 5 may be 25 to 125 mm or 40 to 125 mm.
- the thickness t 1 of the web 6 of the H-section steel 4 is not particularly limited, but is preferably 15 to 125 mm.
- the ratio of the thickness of the flange 5 to the thickness of the web 6 (t 2 / t 1 ) is preferably set to 0.5 to 2.0 assuming that the H-section steel 4 is manufactured by hot rolling. . If the ratio of the thickness of the flange 5 to the thickness of the web 6 (t 2 / t 1 ) exceeds 2.0, the web 6 may be deformed into a wavy shape. On the other hand, when the ratio of the thickness of the flange 5 to the thickness of the web 6 (t 2 / t 1 ) is less than 0.5, the flange 5 may be deformed into a wavy shape.
- the target value of the mechanical properties of the H-section steel 4 according to the H-section steel of the present disclosure is the yield strength or the 0.2% yield strength at room temperature in the test piece when evaluating the above-described yield strength or 0.2% yield strength. Is 385 MPa or more, and the tensile strength is 490 MPa or more.
- the yield strength or 0.2% yield strength is a stress-strain curve, and indicates that the yield strength is obtained when the yield phenomenon appears, and the 0.2% yield strength is obtained when the yield phenomenon does not appear. That is, when the yield phenomenon appears, the yield strength is 385 MPa or more, and when the yield phenomenon does not appear, the 0.2% proof stress is 385 MPa or more.
- the target value of Charpy absorbed energy at ⁇ 20 ° C. in the H-section steel 4 of the present disclosure is 200 J or more in the test piece 9 described above. If the strength is too high, the toughness may be impaired. Therefore, the yield strength at normal temperature or the 0.2% yield strength is preferably 530 MPa or less, and the tensile strength is preferably 690 MPa or less. In the present disclosure, normal temperature refers to a range of 20 ° C. ⁇ 5 ° C.
- the preferable manufacturing method of the H-section steel 4 of this indication has the following processes. 1) A step of heating a steel slab having the above component composition (chemical composition) to 1100 to 1350 ° C. 2) Rolling is started after heating, and the cumulative rolling reduction A at a surface temperature of 900 ° C. to 1100 ° C. or less is more than 10% at a position of (1/6) F from the flange width direction end face in the width direction of the flange. Rolling, rolling at 750 ° C. to less than 900 ° C. with a cumulative rolling reduction B of 10% or more, and finishing the rolling with a surface temperature of 750 ° C.
- the chemical composition of the molten steel is adjusted so as to have the above-described composition, and then cast to obtain a steel slab.
- Casting is not particularly limited, and a beam blank having a shape close to the H-section steel 4 to be manufactured may be used. From the viewpoint of productivity, continuous casting is preferable.
- the thickness of a steel piece shall be 200 mm or more from a viewpoint of productivity. In consideration of the reduction of segregation and the uniformity of the heating temperature before hot rolling, the thickness of the steel slab is preferably 350 mm or less.
- the lower limit of the heating temperature of the steel slab is 1100 ° C.
- the heating temperature of the steel slab is less than 1100 ° C.
- the lower limit of the heating temperature of the steel slab is preferably 1150 ° C.
- the upper limit of the heating temperature of the steel slab is 1350 ° C.
- the hot rolling is started.
- ferrite, bainite, and the like are refined by austenite grain refinement so that the average crystal grain size is 38 ⁇ m or less. Therefore, the reduction rate when performing hot rolling is such that the surface temperature is 900 ° C. to 1100 at a position of (1/6) F from the width direction end face 5a of the flange 5 in FIG.
- the cumulative rolling reduction A at 10 ° C. is more than 10%
- the cumulative rolling reduction B at 750 ° C. to less than 900 ° C. is 10% or more.
- the hot rolling may be performed, for example, as shown in FIG.
- finish rolling having a cumulative reduction ratio B is performed.
- the cumulative rolling reductions A and B are the difference between the flange thickness before rolling and the flange thickness after rolling divided by the flange thickness before rolling.
- the hardenability may be reduced.
- ferrite transformation may start and YS or TS may decrease. Therefore, the lower limit of the rolling finishing temperature is 750 ° C. at the surface temperature.
- the rolling step the rolling is completed by setting the surface temperature to 750 ° C. or more and the thickness of the flange 5 to 25 to 140 mm (may be 25 to 125 mm).
- the upper limit of the rolling finishing temperature is preferably 850 ° C.
- YS means yield strength or 0.2% proof stress.
- TS is the tensile strength.
- accelerated cooling is applied.
- the cooling may be performed continuously or intermittently with air cooling interposed therebetween.
- the average cooling rate at the measurement position 7 shown in FIG. 1 is set to 0.4 ° C./s or more.
- the cooling rate is derived by calculation based on the shape of the steel material after rolling, the starting temperature of accelerated cooling, and the recuperated temperature after stopping accelerated cooling.
- the target strength cannot be obtained at an average cooling rate of less than 0.4 ° C./s.
- the average cooling rate is preferably 2.0 ° C./s or less.
- setting the average cooling rate to 2.0 ° C./s or less is an example of a preferred embodiment, and the upper limit of the average cooling rate is not limited.
- a process in which primary rolling and cooling to 500 ° C. or lower, followed by heating to 1100 to 1350 ° C. and secondary rolling may be adopted.
- the hot rolling may be water cooling rolling between passes.
- the water cooling between passes is aimed at the temperature fall in a temperature range higher than the temperature at which austenite undergoes phase transformation.
- the H-section steel 4 produced by hot rolling under the above conditions is excellent in strength and low temperature toughness. Further, by containing Nb and V, ferrite, bainite and the like are refined, and the H-section steel 4 excellent in strength and low-temperature toughness is obtained. More specifically, in the H-section steel 4, the flange 5 has a thickness of 25 to 140 mm (may be 25 to 125 mm). In addition, the H-section steel 4 has a yield strength or 0.2% yield strength in the tensile test of 385 MPa or more, a tensile strength of 490 MPa or more, and a Charpy absorbed energy at ⁇ 20 ° C. in the test piece 9 of 200 J or more. Show.
- the manufactured H-section steel 4 becomes a high-strength, extremely-thick H-section steel 4 having excellent low-temperature toughness.
- the manufacturing method of the H-section steel 4 of this indication does not require an advanced steelmaking technique and accelerated cooling, and can aim at reduction of manufacturing load, shortening of a work period, etc. Accordingly, the industrial contribution is extremely significant, such as improving the reliability of large buildings without impairing the economy.
- H-section steel of the present disclosure will be specifically described based on examples, the H-section steel of the present disclosure is not limited to the examples.
- the manufacturing process of H-section steel 4 is shown in FIG.
- the steel slab heated in the heating furnace 1 was carried out in a universal rolling device row including a rough rolling mill 2a, an intermediate rolling mill 2b, and a finishing rolling mill 2c. After completion of hot rolling, accelerated cooling was applied continuously or intermittently with air cooling interposed therebetween.
- accelerated cooling was applied continuously or intermittently with air cooling interposed therebetween.
- water cooling between the rolling passes is performed by using a water cooling device 3 provided before and after the intermediate universal rolling mill (intermediate rolling mill 2b), and spray cooling and reverse rolling of the flange outer surface. Went.
- a specimen for microscopic observation was collected from the H-section steel 4 so as to include a surface perpendicular to the width direction of the flange 5 with the measurement position 7 shown in FIG. 1 as the center. did.
- the surface was subjected to EBSD observation, and the average crystal grain size was measured.
- the MA area fraction of the surface is measured using a specimen for microscopic observation taken from the H-section steel 4 so as to include a surface perpendicular to the width direction of the flange 5 with the measurement position 7 as the center. did.
- a Charpy test was performed at ⁇ 20 ° C. using a Charpy test piece (see FIG.
- the tensile test was performed in accordance with JIS Z 2241 (2011). Yield point was obtained when the yield behavior was exhibited, and 0.2% proof stress was obtained when the yield behavior was not exhibited.
- the test piece for the tensile test was JIS1A, and the measurement temperature was 20 ° C. ⁇ 5 ° C.
- the Charpy impact test was performed at ⁇ 20 ° C. according to JIS Z 2242 (2005).
- the target values of mechanical properties are that yield strength at normal temperature or 0.2% yield strength (YS) is 385 MPa or more, and tensile strength (TS) is 490 MPa or more.
- the target value of Charpy absorbed energy (vE -20 ) at -20 ° C is 200 J or more.
- the notch shape of the Charpy test was V notch and the notch depth was 2 mm.
- Table 3 to Table 6 show the absorbed energy (vE -20 ) of the Charpy test at.
- the reduction rate when performing hot rolling in Table 3 and Table 5 is from the width direction end surface 5a of the flange 5 of FIG. 1 toward the width direction of the flange 5 (X-axis direction shown in FIG. 1). 1/6)
- the average cooling rate at the measurement position 7 is calculated by computer simulation from the measured values of the flange thickness t 2 , the water cooling start temperature, and the recuperation temperature of the H-section steel 4.
- manufacturing No. 5, 8, 14, 15, 18, and 19 (Tables 3 and 4), and 24-39 (Tables 5 and 6) are any one of chemical composition, Ceq, cumulative rolling reduction A, cumulative rolling reduction B, rolling finishing temperature, average cooling rate, average crystal grain size, and area fraction of MA.
- Ceq cumulative rolling reduction A
- cumulative rolling reduction B rolling finishing temperature
- average cooling rate average crystal grain size
- area fraction of MA one or more are outside the scope of the H-section steel of the present disclosure. Therefore, any one or more of YS, TS, and Charpy absorbed energy at ⁇ 20 ° C. did not satisfy the target value.
- the metal structure of each example was 10% or less of pearlite and 1.2% of MA, and the rest other than these consisted of ferrite (polygonal ferrite) and at least one of bainite and acicular ferrite.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Architecture (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Structural Engineering (AREA)
- Civil Engineering (AREA)
- Heat Treatment Of Steel (AREA)
- Metal Rolling (AREA)
Abstract
Description
特許文献2:日本国特開2006-322019号公報
特許文献3:日本国特開平11-335735号公報
特許文献4:日本国特開2016-141834号公報
特許文献5:日本国特開平8-197103号公報
特許文献6:日本国特開2006-249475号公報
特許文献7:国際公開2001-075182号
しかしながら、特許文献1~5には、強度および低温靭性に優れ、かつ極厚のH形鋼を得るための構成及び製造方法が記載されていないため、このような特性を有するH形鋼が得られなかった。また、特許文献6に開示されるH形鋼は、低温靭性が十分ではなかった。さらに、特許文献7に開示されるH形鋼は、主にフェライト相とパーライト相から形成されるため、靭性が安定しないことが判明している。
(1)
質量%で、
C :0.040~0.100%、
Mn:0.50~1.70%、
Cu:0.01~0.50%、
Ni:0.01~0.50%、
Cr:0.01~0.50%、
Nb:0.001~0.050%、
V :0.010~0.120%、
Al:0.005~0.100%、
Ti:0.001~0.025%、
B:0.0005超~0.0020%、
N :0.0001~0.0120%、
Si:0~0.08%、
Mo:0~0.20%、
W :0~0.50%、
Ca:0~0.0050%
Zr:0~0.0050%
Mg:0~0.0050%
REM:0~0.005%、並びに、
残部:Feおよび不純物からなり、
下記式(1)によって求められる炭素当量Ceqが0.300~0.480であり、
フランジの厚みが25~140mmであり、
フランジの幅方向長さをF、厚みをt2とすると、
フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置であって、かつ、フランジの厚さ方向で、フランジの厚さ方向外側の面から(1/4)t2である位置を測定位置の中心とし、フランジの幅方向と直交する面における平均結晶粒径が38μm以下であり、
前記測定位置を中心とし、フランジの幅方向と直交する面における鋼材組織中のマルテンサイト-オーステナイト混合組織(MA)の面積分率が1.2%以下であり、
フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置であって、かつ、フランジの厚さ方向の全厚に対して測定した、フランジの圧延方向の降伏強度または0.2%耐力が385MPa以上であり、引張強度が490MPa以上であり、
前記測定位置における-20℃でのシャルピー試験の吸収エネルギーが200J以上である、H形鋼。
式(1) Ceq=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15
ここで、C、Mn、Cr、Mo、V、Ni、及びCuは各元素の含有量(質量%)を表す。含有されない場合は0とする。
(2)
(1)に記載のH形鋼を製造する方法であって、
(1)に記載の成分組成を有する鋼片を1100~1350℃に加熱する工程と、
前記加熱後に圧延を開始し、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置において、表面温度900℃以上、1100℃以下での累積圧下率Aが10%超で圧下し、900℃未満、750℃以上での累積圧下率Bが10%以上で圧延する圧延を行い、表面温度が750℃以上でフランジの厚みを25~140mmとして圧延を終了する工程と、
前記圧延後、フランジの幅方向長さをF、厚みをt2とすると、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置であって、かつ、フランジの厚さ方向で、フランジの厚さ方向外側の面から(1/4)t2の位置において、平均冷却速度が0.4℃/s以上である加速冷却を、連続的にまたは間に空冷を挟んで断続的に行う工程と、
を有するH形鋼の製造方法。
(3)
前記加速冷却は、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置における、冷却停止後の復熱温度が600℃以下となるまで加速冷却する、(2)に記載のH形鋼の製造方法。
本開示において、成分(元素)の含有量を示す「%」は、「質量%」を意味する。
本開示において、「工程」との用語は、独立した工程だけではなく、他の工程と明確に区別できない場合であってもその工程の所期の目的が達成されるのであれば、本用語に含まれる。
また、フランジの厚みが25~140mmである。
さらに、フランジの幅方向長さをF、厚みをt2とすると、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置であって、かつ、フランジの厚さ方向で、フランジの厚さ方向外側の面から(1/4)t2である位置を測定位置の中心とし、フランジの幅方向と直交する面におけるフェライト平均結晶粒径が38μm以下である。
前記測定位置を中心とし、フランジの幅方向と直交する面における鋼材組織中のマルテンサイト-オーステナイト混合組織(MA)の面積分率が1.2%以下である。
そして、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置であって、かつ、フランジの厚さ方向の全厚に対して測定した、フランジの圧延方向の降伏強度または0.2%耐力が385MPa以上であり、引張強度が490MPa以上である。
前記測定位置における-20℃でのシャルピー試験の吸収エネルギーが200J以上である。
上述したように、フランジの厚みが25mm以上である極厚H形鋼には、室温か、せいぜい0℃での靭性が要求されていた。しかしながら、現在では寒冷地等での使用を考慮して、より低温(-20℃程度)での靭性が要求される場合がある。また、極厚H形鋼の重量低減を図るため、降伏強度の高い(具体的には、降伏強度又は0.2%耐力が385MPa以上)鋼材の需要が高まっている。
以上が本開示のH形鋼を創出するに至った経緯である。
まず、成分組成(化学組成)の限定理由について説明する。
Cは、鋼の強化に有効な元素であり、本開示のH形鋼ではC含有量の下限値を0.040%とする。C含有量の好ましい下限値は、0.050%である。一方、C含有量が0.100%を超えると、セメンタイト及びMAの生成量が過剰となり、靭性の低下を招く。そのため、C含有量の上限を0.100%とする。C含有量の好ましい上限は0.080%である。
Mnは、強度の向上に寄与するため、本開示のH形鋼ではMn含有量の下限を0.50%とする。より強度を高めるには、Mn含有量の下限を1.00%にすることが好ましい。一方、Mn含有量が1.70%を超えると、焼入性が過剰に上昇し、MAの生成を助長して靭性を損なう。そのため、Mn含有量の上限を1.70%とする。Mn含有量の好ましい上限は1.60%である。
Cuは、焼入性を向上させ、引張強度の向上に寄与する。この効果を得るには、Cu含有量を0.01%以上とする。Cu含有量の好ましい下限は0.10%である。しかし、Cu含有量が過剰になると、靭性の低下を招くことがある。そのため、Cu含有量の上限は0.50%とする。Cu含有量の好ましい上限は0.30%である。
Niは、鋼中に固溶して焼入性を高める元素であり、引張強度の向上に寄与する。引張強度の向上のために、Ni含有量を0.01%以上とする。Ni含有量の好ましい下限値は0.10%である。しかし、Ni含有量が0.50%超では焼入性を過剰に向上させ、MAの生成を助長し靭性を低下させる。従って、Ni含有量の上限を0.50%とする。Ni含有量の好ましい上限は0.30%である。
Crは、焼入性を上昇させて引張強度の向上に寄与する元素である。引張強度の向上のために、Cr含有量を0.01%以上とする。Cr含有量の好ましい下限は0.05%である。しかし、Cr含有量が0.50%超では、焼入性を過剰に向上させ、MAの生成を助長し靭性を低下させる。従って、Cr含有量の上限を0.50%とする。Cr含有量の好ましい上限は0.30%である。
Nbは、熱間圧延を行うときに、オーステナイトの再結晶を抑制し、鋼材中に加工歪を蓄積させることでフェライト及びベイナイトの細粒化に寄与し、さらに、析出強化により強度の向上に寄与する。これらの効果を得るために、Nb含有量を0.001%以上とする。Nb含有量の好ましい下限は0.010%である。ただし、Nbを過度に含有すると、MAの生成を助長し、著しい靭性の低下を招くことがある。そのため、Nb含有量の上限を0.050%とする。Nb含有量の好ましい上限は0.040%である。
Vは、炭窒化物を形成して析出強化に寄与する。さらに、オーステナイトの粒内に析出したVの炭窒化物は、フェライト及びベイナイトの変態核として作用し、フェライト及びベイナイトの結晶粒を微細化する効果も有する。これらの効果を得るために、V含有量を0.010%以上とする。V含有量の好ましい下限は0.030%であり、より好ましい下限は0.050%である。しかし、Vを過剰に含有すると、析出物の粗大化に起因して靭性を損なうことがある。そのため、V含有量の上限を0.120%とする。V含有量の好ましい上限は0.100%である。
Alは、本開示のH形鋼では脱酸元素として作用する。脱酸の効果を得るために、Al含有量を0.005%以上とする。一方、Alを過剰に含有すると、Al酸化物が粗大化して脆性破壊の基点となり、靭性が低下する。そのため、Al含有量の上限を0.100%とする。
Tiは、TiNを形成して、鋼中のNを固定する元素である。この効果を得るため、本開示のH形鋼では、Ti含有量の下限を0.001%とする。また、TiNは、ピンニング効果によって、オーステナイトを細粒化する効果を有する。そのため、Ti含有量の好ましい下限は0.007%である。一方、Ti含有量が0.025%を超えると、粗大なTiNが生成し、靭性を損なう。そのため、Ti含有量の上限を0.025%とする。Ti含有量の好ましい上限は0.020%である。
Bは、焼入性を高めて鋼材の強度上昇をもたらす元素である。この効果を得るため、本開示のH形鋼では、B含有量の下限を0.0005%超とする。B含有量の好ましい下限は0.0006%である。一方、B含有量が過剰になると、MAの生成を助長し、靭性を低下させるため、B含有量の上限を0.0020%とする。B含有量の好ましい上限は0.0015%である。
Nは、TiN及びVNを形成し、組織の細粒化及び析出強化に寄与する元素である。そのため、N含有量の下限を0.0001%とし、0.0010%を下限としてもよい。しかし、N含有量が過剰になると、母材の靭性が低下し、鋳造を行うときの表面割れ及び製造された鋼材の歪時効による材質不良の原因となる。そのため、N含有量の上限を0.0120%とする。好ましくは、N含有量の好ましい上限は0.0080%である。
P、S、及びOは不純物であり、これらの含有量は特に限定されない。しかし、P及びSは、凝固偏析による溶接割れ及び靭性低下の原因となるので、P及びSの含有量は低減することが好ましい。P含有量の上限は0.03%に制限することが好ましい。P含有量のより好ましい上限は0.01%である。また、S含有量の上限は、0.02%に制限することが好ましい。なお、P含有量及びS含有量の下限値は特に限定されず、0%超でもよい。例えば、脱燐コスト低減および脱硫コスト低減の点から、それぞれ0.0001%以上であってもよい。また、Oは過剰に含有させると、固溶O(固溶酸素)の影響及び酸化物粒子の粗大化によって靭性が低下する。そのため、O含有量の上限を0.0050%とすることが好ましい。O含有量のより好ましい上限は0.0030%である。なお、O含有量の下限値は特に限定されないが、0%超でもよく、0.0001%以上であってもよい。
Siは、脱酸元素であり、強度の向上にも寄与する。本開示のH形鋼では、Siの含有量が大きいと、MAの生成を助長して靭性の劣化をもたらすため、Si含有量の上限を0.08%とする。Si含有量の好ましい上限は0.05%である。Si含有量は、MAの生成を抑制する点で、少ないほど好ましい。Siを含有する場合、Si含有量の下限は特に限定されない。例えば、Siを含有する場合におけるSi含有量の下限は0%超であってもよく、0.01%であってもよい。
Moは、鋼中に固溶して焼入性を高める元素である。この効果を得るためには、Mo含有量を0.01%以上とすることが好ましく、0.05%以上とすることがより好ましい。しかし、0.20%超のMoを含有させると、MAの生成を助長して靭性の低下を招くことがある。そのため、Mo含有量の上限を0.20%とする。
Wは、鋼中に固溶して焼入性を高める元素である。この効果を得るためには、W含有量を0.01%以上とすることが好ましく、0.10%以上とすることがより好ましい。しかし、0.50%超のWを含有させると、MAの生成を助長して靭性の低下を招くことがある。そのため、W含有量の上限を0.50%とする。
Caは、硫化物の形態制御に有効な元素であり、粗大なMnSの生成を抑制し、靭性の向上に寄与する。この効果を得るためには、Ca含有量を0.0001%以上とすることが好ましく、0.0010%以上とすることがより好ましい。一方、0.0050%を超えるCaを含有させると、靭性が低下することがある。そのため、Ca含有量の上限は0.0050%とする。Ca含有量のより好ましい上限は0.0030%である。
Zrは、炭化物および窒化物として析出し、鋼の析出強化に寄与する。この効果を得るためには、Zr含有量を0.0001%以上とすることが好ましく、0.0010%以上とすることがより好ましい。一方、0.0050%を超えるZrを含有させると、Zrの炭化物および窒化物の粗大化を招き靭性が低下することがある。そのため、Zr含有量の上限は0.0050%とする。
その他、本開示のH形鋼では、母材靭性及び溶接HAZ靭性の向上を目的として、Mg及びREM(希土類元素;即ち、Sc、Y、La、Ce、Pr、Nd、Pm、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、及びLuからなる群から選択される少なくとも1種の元素を指す。)の元素の1種または2種以上を含有していてもよい。これらの元素の下限値は0%である。ただし、これら元素を過剰に含有すると、母材靭性及び溶接HAZ靭性の向上効果が得られない。そのため、Mgを含有する場合、Mg含有量の下限は0.0001%とすることがよい。Mg含有量の上限は0.0050%以下とする。Mg含有量の好ましい上限は0.0032%である。また、REMを含有する場合、REM含有量の下限は0.001%とすることがよい。REM含有量の上限は0.005%以下である。REM含有量の好ましい上限は0.003%である。
また、本開示のH形鋼の化学組成において、残部はFeおよび不純物からなる。ここで、不純物とは、原材料に含まれる成分、または、製造の工程で混入する成分であって、意図的に鋼に含有させたものではない成分を指す。
式(1) Ceq=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15
ここで、C、Mn、Cr、Mo、V、Ni、及びCuは各元素の含有量(質量%)を表す。含有されない場合は0とする。つまり、式(1)において、H形鋼が、C、Mn、Cr、Mo、V、Ni、及びCuの元素を含有する場合は、含有する各元素の含有量(質量%)を代入する。また、含有しない元素がある場合は、0を代入する。
H形鋼4は、互いに対向する一対の板状のフランジ5と、フランジ5と直交するように、かつフランジ5の対向面の幅方向中心を連結するように設けられた、板状のウェブ6を備える。
図1において、X軸方向をフランジ5の幅方向と定義し、Y軸方向をフランジ5の厚さ方向と定義し、Z軸方向を圧延方向(フランジ5の長さ方向)と定義する。
引張試験により、降伏強度または0.2%耐力を評価する際の試験片は、図1において、フランジ5の幅方向端面5aから、フランジ5の幅方向(図1に示すX軸方向)に向かって、(1/6)Fの位置を、試験片の幅方向中心として切り出した試験片である。この試験片を用いて、引張試験を行う。試験片は、試験片の長手方向が圧延方向(図1に示すZ軸方向)と平行であり、また、フランジ5の厚さ方向(図1に示すY軸方向)の全部(全厚)から切り出すようにすればよい。試験片の幅方向の厚さは、JIS Z 2241(2011)に規定の範囲とする。なお、上記試験片は、フランジ5の幅方向端面5aから、フランジ5の幅方向に向かって、(1/6)Fの位置が、試験片の幅方向中心であれば、圧延方向におけるどの位置から採取してもよい。
本開示のH形鋼4のフランジ5の厚みt2は、25~140mmとする。厚みt2の下限を25mmとしたのは、例えば、高層建築構造物に用いられるH形鋼4に、フランジ5の厚みt2が25mm以上の強度部材が求められているためである。フランジ5の厚みt2の好ましい下限は40mmである。一方、フランジ5の厚みt2の上限を140mmとしたのは、フランジ5の厚みt2が140mmを超えると、熱間加工の加工量が不足し強度と靭性の両立が難しいためである。H形鋼4のフランジ5の厚みt2の好ましい上限は125mmである。そのため、フランジ5の厚みt2は、25~125mmであってもよく、40~125mmであってもよい。H形鋼4のウェブ6の厚みt1は特に規定しないが、15~125mmであることが好ましい。
ここで、降伏強度または0.2%耐力とは、応力-歪曲線で、降伏現象が現れる場合は降伏強度を求め、降伏現象が現れない場合は0.2%耐力を求めることを示す。つまり、降伏現象が現れる場合は降伏強度が385MPa以上であり、降伏現象が現れない場合は0.2%耐力が385MPa以上であることを意味する。
本開示のH形鋼4の好ましい製造方法は、下記の工程を有する。
1)前述の成分組成(化学組成)を有する鋼片を1100~1350℃に加熱する工程。
2)加熱後に圧延を開始し、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置において、表面温度900℃~1100℃以下での累積圧下率Aが10%超で圧下し、750℃~900℃未満での累積圧下率Bが10%以上で圧延する圧延を行い、表面温度が750℃以上でフランジの厚みを25~140mmとして圧延を終了する工程。
3)圧延後、フランジの幅方向長さをF、厚みをt2とすると、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置であって、かつ、フランジの厚さ方向で、フランジの厚さ方向外側の面から(1/4)t2の位置において、平均冷却速度が0.4℃/s以上である加速冷却を、連続的にまたは間に空冷を挟んで断続的に行う工程。
以下、各工程について、具体的に説明する。
製造No.8は、加速冷却の際の図1の測定位置7での平均冷却速度が0.4℃/s未満であったため、YSおよびTSが目標を満足しなかった。
製造No.14およびNo.18は、900℃~1100℃での圧下率(累積圧下率A)が不十分であった。そのため、平均結晶粒径が本開示のH形鋼の範囲外となり、-20℃でのシャルピー吸収エネルギーが目標値に達しなかった。
製造No.15およびNo.19は、900℃未満~750℃以上での圧下率(累積圧下率B)が不十分であった。そのため、平均結晶粒径が本開示のH形鋼の範囲外となり、-20℃でのシャルピー吸収エネルギーが目標値に達しなかった。
1 加熱炉
2a 粗圧延機
2b 中間圧延機
2c 仕上圧延機
3 中間圧延機前後の水冷装置
4 H形鋼
5 フランジ
5a フランジの幅方向端面
5b フランジの厚さ方向外側の面
6 ウェブ
7 靭性および鋼材組織の測定位置
9 試験片
本明細書に記載された全ての文献、特許出願、および技術規格は、個々の文献、特許出願、および技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。
Claims (3)
- 成分組成が、質量%で、
C :0.040~0.100%、
Mn:0.50~1.70%、
Cu:0.01~0.50%、
Ni:0.01~0.50%、
Cr:0.01~0.50%、
Nb:0.001~0.050%、
V :0.010~0.120%、
Al:0.005~0.100%、
Ti:0.001~0.025%、
B :0.0005超~0.0020%、
N :0.0001~0.0120%、
Si:0~0.08%、
Mo:0~0.20%、
W :0~0.50%、
Ca:0~0.0050%、
Zr:0~0.0050%、
Mg:0~0.0050%
REM:0~0.005%、並びに、
残部:Feおよび不純物からなり、
下記式(1)によって求められる炭素当量Ceqが0.300~0.480であり、
フランジの厚みが25~140mmであり、
フランジの幅方向長さをF、厚みをt2とすると、
フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置であって、かつ、フランジの厚さ方向で、フランジの厚さ方向外側の面から(1/4)t2である位置を測定位置の中心とし、フランジの幅方向と直交する面における平均結晶粒径が38μm以下であり、
前記測定位置を中心とし、フランジの幅方向と直交する面における鋼材組織中のマルテンサイト-オーステナイト混合組織(MA)の面積分率が1.2%以下であり、
フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置であって、かつ、フランジの厚さ方向の全厚に対して測定した、フランジの圧延方向の降伏強度または0.2%耐力が385MPa以上であり、引張強度が490MPa以上であり、
前記測定位置における-20℃でのシャルピー試験の吸収エネルギーが200J以上である、H形鋼。
式(1) Ceq=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15
ここで、C、Mn、Cr、Mo、V、Ni、及びCuは各元素の含有量(質量%)を表す。含有されない場合は0とする。 - 請求項1に記載のH形鋼を製造する方法であって、
請求項1に記載の成分組成を有する鋼片を1100~1350℃に加熱する工程と、
前記加熱後に圧延を開始し、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置において、表面温度900℃以上、1100℃以下での累積圧下率Aが10%超で圧下し、900℃未満、750℃以上での累積圧下率Bが10%以上で圧延する圧延を行い、表面温度が750℃以上でフランジの厚みを25~140mmとして圧延を終了する工程と、
前記圧延後、フランジの幅方向長さをF、厚みをt2とすると、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置であって、かつ、フランジの厚さ方向で、フランジの厚さ方向外側の面から(1/4)t2の位置において、平均冷却速度が0.4℃/s以上である加速冷却を、連続的にまたは間に空冷を挟んで断続的に行う工程と、
を有するH形鋼の製造方法。 - 前記加速冷却は、フランジの幅方向で、フランジの幅方向端面から(1/6)Fの位置における、冷却停止後の復熱温度が600℃以下となるまで加速冷却する請求項2に記載のH形鋼の製造方法。
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SG11201907436YA SG11201907436YA (en) | 2017-03-15 | 2018-03-15 | H-section steel and method of producing the same |
JP2019506276A JP6787479B2 (ja) | 2017-03-15 | 2018-03-15 | H形鋼およびその製造方法 |
US16/488,810 US11041231B2 (en) | 2017-03-15 | 2018-03-15 | H-section steel and method of producing the same |
CN201880011844.2A CN110291218B (zh) | 2017-03-15 | 2018-03-15 | H型钢及其制造方法 |
EP18766786.0A EP3597783B1 (en) | 2017-03-15 | 2018-03-15 | H-section steel and method of producing the same |
CA3054279A CA3054279A1 (en) | 2017-03-15 | 2018-03-15 | H-section steel and method of producing the same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2017049844 | 2017-03-15 | ||
JP2017-049844 | 2017-03-15 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2018169020A1 true WO2018169020A1 (ja) | 2018-09-20 |
Family
ID=63523905
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2018/010339 WO2018169020A1 (ja) | 2017-03-15 | 2018-03-15 | H形鋼およびその製造方法 |
Country Status (7)
Country | Link |
---|---|
US (1) | US11041231B2 (ja) |
EP (1) | EP3597783B1 (ja) |
JP (1) | JP6787479B2 (ja) |
CN (1) | CN110291218B (ja) |
CA (1) | CA3054279A1 (ja) |
SG (1) | SG11201907436YA (ja) |
WO (1) | WO2018169020A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2020158823A1 (ja) * | 2019-01-31 | 2020-08-06 | Jfeスチール株式会社 | 突起付きh形鋼およびその製造方法 |
JP7440757B2 (ja) | 2020-03-27 | 2024-02-29 | 日本製鉄株式会社 | H形鋼およびその製造方法 |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111733368A (zh) * | 2020-07-10 | 2020-10-02 | 武钢集团昆明钢铁股份有限公司 | 一种隧道支护用高强度抗震工字钢及其制备方法 |
CN112458364B (zh) * | 2020-11-04 | 2021-09-03 | 马鞍山钢铁股份有限公司 | 一种超厚规格热轧h型钢及其生产方法 |
JP7405246B2 (ja) * | 2021-03-03 | 2023-12-26 | Jfeスチール株式会社 | H形鋼 |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08197103A (ja) | 1995-01-23 | 1996-08-06 | Kawasaki Steel Corp | 強度、靭性及び溶接性に優れた極厚h形鋼の製造方法 |
US5858130A (en) * | 1997-06-25 | 1999-01-12 | Bethlehem Steel Corporation | Composition and method for producing an alloy steel and a product therefrom for structural applications |
JPH11335735A (ja) | 1998-03-24 | 1999-12-07 | Sumitomo Metal Ind Ltd | 溶接性、強度および靱性に優れた極厚形鋼の製造法 |
WO2001075182A1 (fr) | 2000-04-04 | 2001-10-11 | Nippon Steel Corporation | Profile en acier lamine en forme de h a microstructure uniforme et proprietes mecaniques uniformes ; procede de fabrication |
JP2003328070A (ja) | 2002-05-14 | 2003-11-19 | Sumitomo Metal Ind Ltd | 極厚鋼材およびその製造方法 |
JP2006249475A (ja) | 2005-03-09 | 2006-09-21 | Jfe Steel Kk | 低温靭性に優れる圧延h形鋼の製造方法 |
JP2006322019A (ja) | 2005-05-17 | 2006-11-30 | Sumitomo Metal Ind Ltd | 熱加工制御型590MPa級H形鋼及びその製造方法 |
JP2016141834A (ja) | 2015-01-30 | 2016-08-08 | 新日鐵住金株式会社 | 靭性に優れた高強度極厚h形鋼及びその製造方法 |
JP2017049844A (ja) | 2015-09-02 | 2017-03-09 | 株式会社らかんスタジオ | 画像処理システム |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4276576B2 (ja) | 2004-04-20 | 2009-06-10 | 新日本製鐵株式会社 | 大入熱溶接熱影響部靭性に優れた厚手高強度鋼板 |
JP2006063443A (ja) * | 2004-07-28 | 2006-03-09 | Nippon Steel Corp | 耐火性に優れたh形鋼およびその製造方法 |
JP5176885B2 (ja) | 2008-11-10 | 2013-04-03 | 新日鐵住金株式会社 | 鋼材及びその製造方法 |
JP4874435B2 (ja) * | 2010-02-08 | 2012-02-15 | 新日本製鐵株式会社 | 厚鋼板の製造方法 |
JP5574059B2 (ja) | 2011-12-15 | 2014-08-20 | 新日鐵住金株式会社 | 低温靭性に優れた高強度h形鋼及びその製造方法 |
CN102605243B (zh) * | 2012-03-15 | 2013-12-25 | 莱芜钢铁集团有限公司 | 风电用h型钢及其生产方法 |
EP2865779B1 (en) * | 2012-11-26 | 2018-03-21 | Nippon Steel & Sumitomo Metal Corporation | H-Section steel and process for producing same |
CN104018073B (zh) * | 2014-06-19 | 2015-11-18 | 马钢(集团)控股有限公司 | 一种耐低温韧性h型钢及其生产工艺 |
JP6354572B2 (ja) * | 2014-10-27 | 2018-07-11 | 新日鐵住金株式会社 | 低温用h形鋼及びその製造方法 |
-
2018
- 2018-03-15 CA CA3054279A patent/CA3054279A1/en not_active Abandoned
- 2018-03-15 EP EP18766786.0A patent/EP3597783B1/en active Active
- 2018-03-15 CN CN201880011844.2A patent/CN110291218B/zh active Active
- 2018-03-15 US US16/488,810 patent/US11041231B2/en active Active
- 2018-03-15 SG SG11201907436YA patent/SG11201907436YA/en unknown
- 2018-03-15 WO PCT/JP2018/010339 patent/WO2018169020A1/ja unknown
- 2018-03-15 JP JP2019506276A patent/JP6787479B2/ja active Active
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08197103A (ja) | 1995-01-23 | 1996-08-06 | Kawasaki Steel Corp | 強度、靭性及び溶接性に優れた極厚h形鋼の製造方法 |
US5858130A (en) * | 1997-06-25 | 1999-01-12 | Bethlehem Steel Corporation | Composition and method for producing an alloy steel and a product therefrom for structural applications |
JPH11335735A (ja) | 1998-03-24 | 1999-12-07 | Sumitomo Metal Ind Ltd | 溶接性、強度および靱性に優れた極厚形鋼の製造法 |
WO2001075182A1 (fr) | 2000-04-04 | 2001-10-11 | Nippon Steel Corporation | Profile en acier lamine en forme de h a microstructure uniforme et proprietes mecaniques uniformes ; procede de fabrication |
JP2003328070A (ja) | 2002-05-14 | 2003-11-19 | Sumitomo Metal Ind Ltd | 極厚鋼材およびその製造方法 |
JP2006249475A (ja) | 2005-03-09 | 2006-09-21 | Jfe Steel Kk | 低温靭性に優れる圧延h形鋼の製造方法 |
JP2006322019A (ja) | 2005-05-17 | 2006-11-30 | Sumitomo Metal Ind Ltd | 熱加工制御型590MPa級H形鋼及びその製造方法 |
JP2016141834A (ja) | 2015-01-30 | 2016-08-08 | 新日鐵住金株式会社 | 靭性に優れた高強度極厚h形鋼及びその製造方法 |
JP2017049844A (ja) | 2015-09-02 | 2017-03-09 | 株式会社らかんスタジオ | 画像処理システム |
Non-Patent Citations (1)
Title |
---|
See also references of EP3597783A4 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2020158823A1 (ja) * | 2019-01-31 | 2020-08-06 | Jfeスチール株式会社 | 突起付きh形鋼およびその製造方法 |
JPWO2020158823A1 (ja) * | 2019-01-31 | 2021-02-18 | Jfeスチール株式会社 | 突起付きh形鋼およびその製造方法 |
JP7440757B2 (ja) | 2020-03-27 | 2024-02-29 | 日本製鉄株式会社 | H形鋼およびその製造方法 |
Also Published As
Publication number | Publication date |
---|---|
CA3054279A1 (en) | 2018-09-20 |
SG11201907436YA (en) | 2019-09-27 |
EP3597783A4 (en) | 2020-11-04 |
JPWO2018169020A1 (ja) | 2019-12-12 |
CN110291218B (zh) | 2021-06-22 |
CN110291218A (zh) | 2019-09-27 |
JP6787479B2 (ja) | 2020-11-18 |
EP3597783A1 (en) | 2020-01-22 |
EP3597783B1 (en) | 2022-06-08 |
US20210140024A1 (en) | 2021-05-13 |
US11041231B2 (en) | 2021-06-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2018169020A1 (ja) | H形鋼およびその製造方法 | |
JP6468408B2 (ja) | H形鋼及びその製造方法 | |
EP2975149B1 (en) | H-shaped steel and process for manufacturing same | |
KR101139605B1 (ko) | 고온 특성과 인성이 우수한 강재 및 그 제조 방법 | |
WO2013089156A1 (ja) | 低温靭性に優れた高強度h形鋼及びその製造方法 | |
JP6763141B2 (ja) | Lpgタンク用鋼板の製造方法 | |
EP3085803A1 (en) | H-shaped steel and method for producing same | |
JP6809524B2 (ja) | 超低降伏比高張力厚鋼板およびその製造方法 | |
JP6409598B2 (ja) | 靭性に優れた高強度極厚h形鋼及びその製造方法 | |
JP5402560B2 (ja) | 鋼と圧延鋼材の製造方法 | |
JP6988836B2 (ja) | 超低降伏比高張力厚鋼板およびその製造方法 | |
JP6645107B2 (ja) | H形鋼及びその製造方法 | |
KR20090122371A (ko) | 고온 특성과 인성이 우수한 강재 및 그 제조 방법 | |
EP3133181A1 (en) | Steel h-beam and method for manufacturing same | |
JPWO2011065479A1 (ja) | 高強度極厚h形鋼及びその製造方法 | |
WO2014175122A1 (ja) | H形鋼及びその製造方法 | |
JP5369462B2 (ja) | 低降伏比高張力鋼板およびその製造方法 | |
WO2017150665A1 (ja) | 低温用h形鋼及びその製造方法 | |
JP6354571B2 (ja) | 圧延h形鋼及びその製造方法 | |
JP2007277629A (ja) | 極厚鋼材及びその製造方法 | |
KR20190111920A (ko) | 압연 h형강 및 그 제조 방법 | |
JP2023031269A (ja) | 超低降伏比高張力厚鋼板およびその製造方法 | |
KR102412013B1 (ko) | 열연 강판 | |
JP7077802B2 (ja) | 低降伏比耐火鋼板 | |
JP2017186594A (ja) | 低温用h形鋼及びその製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 18766786 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2019506276 Country of ref document: JP Kind code of ref document: A |
|
ENP | Entry into the national phase |
Ref document number: 3054279 Country of ref document: CA |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2018766786 Country of ref document: EP Effective date: 20191015 |