WO2015181911A1 - 熱延鋼板及びその製造方法 - Google Patents
熱延鋼板及びその製造方法 Download PDFInfo
- Publication number
- WO2015181911A1 WO2015181911A1 PCT/JP2014/064150 JP2014064150W WO2015181911A1 WO 2015181911 A1 WO2015181911 A1 WO 2015181911A1 JP 2014064150 W JP2014064150 W JP 2014064150W WO 2015181911 A1 WO2015181911 A1 WO 2015181911A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- steel sheet
- rolling
- less
- cooling
- hot
- Prior art date
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/60—Aqueous agents
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/613—Gases; Liquefied or solidified normally gaseous material
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
-
- 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
- C22C38/001—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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- 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
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium 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
- C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/008—Martensite
Definitions
- the present invention relates to a high-strength hot-rolled steel sheet excellent in appearance and balance between elongation and hole expansibility and having a tensile strength of 590 MPa or more and a method for producing the same.
- Patent Document 1 proposes a hot-rolled steel sheet having a martensite structure fraction of 3% or more and less than 10%. Patent Document 1 discloses that a hot rolled steel sheet having an excellent balance between elongation and hole expansibility can be obtained by precipitation strengthening ferrite with Ti and Nb to improve strength.
- Patent Document 2 a steel having a composite structure of ferrite and martensite in which Al is added to prevent the generation of Si scale which causes deterioration of chemical conversion treatment and the ratio of ferrite in the microstructure is 40% or more. Is disclosed.
- an object of the present invention is to provide a high-strength hot-rolled steel sheet having a tensile strength of 590 MPa or more and a method for producing the same, which are excellent in appearance and have an excellent balance between elongation and hole expansibility.
- excellent appearance means that there is little generation of a scale pattern on the surface
- excellent balance between elongation and hole expandability means that the elongation is 20% or more and the hole expansion ratio is 100% or more. Indicates having at the same time.
- the present inventors have made various studies on means for solving the above problems.
- the microstructure contains martensite, the strength is improved, but there is a concern that the hole expandability is lowered. Therefore, in order to improve the strength, it is conceivable to use precipitation strengthening of Ti or Nb as an alternative to strength improvement (transformation strengthening) by martensite.
- precipitation strengthening of Ti or Nb as an alternative to strength improvement (transformation strengthening) by martensite.
- Ti or Nb is contained, a texture is formed during hot rolling.
- Al is contained as an alternative to Si that causes the generation of scale patterns in order to improve the appearance, coarse martensite is formed, and the hole expandability deteriorates.
- the present inventors have newly found that it is important to control the austenite structure immediately before transformation.
- the present invention was obtained based on the above findings.
- the gist of the present invention is as follows.
- the chemical components are mass%, C: 0.02 to 0.10%, Si: 0.005 to 0.1%, Mn: 0 0.5 to 2.0%, P: 0.1% or less, S: 0.01% or less, Al: 0.2 to 0.8%, N: 0.01% or less, Ti: 0.01 to 0 11%, Nb: 0 to 0.10%, Ca: 0 to 0.0030%, Mo: 0.02 to 0.5%, Cr: 0.02 to 1.0%, and the balance Fe And the sum of the Si content and the Al content is more than 0.20% and less than 0.81%; the microstructure has an area ratio of 90 to 99% ferrite, 1 -10% martensite and bainite is limited to 5% or less; the martensite grain size is 1-10 ⁇ m; parallel to the rolling surface of the steel sheet; One rolling direction in parallel ⁇ 211 ⁇ ⁇ 011> orientation X-ray random intensity ratio of be 3.0 or less; tensile strength is not
- the chemical components are Nb: 0.01% to 0.10%, Ca: 0.0005 to 0.0030%, Mo: 0.00% in terms of mass%.
- One or more of 02 to 0.5% and Cr: 0.02 to 1.0% may be contained.
- a method for producing a hot-rolled steel sheet according to another aspect of the present invention includes a casting step of obtaining a slab by continuously casting the steel having the chemical component described in (1) or (2) above; A heating step for heating the slab to a temperature range of 1200 ° C. or higher; a rough rolling step for rough rolling the heated slab; and a plurality of rolling mills arranged in series after the rough rolling step.
- a primary cooling step that starts after a second to 1.0 second and water-cools the steel sheet to a temperature range of 600 to 750 ° C. at a cooling rate of 30 ° C./second or more; Air-cooling process to air-cool for 10 seconds ; After the cooling step, the steel sheet, the secondary cooling step and the water-cooled to 200 ° C. or less at a cooling rate of more than 30 ° C. / sec; comprises; a winding step winding the steel sheet after the secondary cooling step.
- the ferrite structural fraction is 90% or more and 99% or less, and the martensite particle size is 1 ⁇ m or more and 10 ⁇ m or less.
- the structure fraction is 1% or more and 10% or less, the X-ray random strength ratio of ⁇ 211 ⁇ ⁇ 011> orientation parallel to the rolling surface and parallel to the rolling direction is 3.0 or less, and the tensile strength is 590 MPa or more.
- a hot-rolled steel sheet is obtained. This hot-rolled steel sheet is excellent in appearance and balance between elongation and hole expansibility.
- the recrystallization of austenite can be promoted and the texture can be improved by setting the finish rolling temperature to 880 ° C. or higher and 1000 ° C. or lower.
- the final reduction rate (reduction rate in the final pass) is set to 20% or more, and after completion of rolling, water cooling is started within 0.01 seconds and within 1.0 seconds, thereby completing recrystallization in a short time.
- fine recrystallized austenite can be formed.
- fine ferrite is formed by performing air cooling after that.
- a high-strength hot-rolled steel sheet having a predetermined microstructure and an X-ray random strength ratio and excellent in appearance and excellent in balance between elongation and hole expansibility and having a tensile strength of 590 MPa or more. can be manufactured.
- the hot-rolled steel sheet according to this embodiment is a high-strength hot-rolled steel sheet having a tensile strength of 590 MPa or more.
- the microstructure in order to improve the hole expandability, has a ferrite structure fraction (area ratio) of 90% or more and a martensite structure fraction. It is effective to set the ratio (area ratio) to 10% or less.
- the structure fraction and the particle size of each structure can be obtained, for example, by performing image analysis on a structure photograph obtained with an optical microscope photograph (field of view: field of view of 500 ⁇ 500 ⁇ m) of a properly corroded steel sheet. it can.
- a steel sheet containing 0.5% or more of Si is air-cooled in a run-out table (hereinafter referred to as ROT) in a hot rolling process ( It is conceivable to apply intermediate air cooling to promote ferrite transformation.
- ROT run-out table
- Si causes a scale pattern due to the Si scale. Therefore, when Si is contained, poor appearance when using a steel plate becomes a problem.
- the hot rolled steel sheet according to the present embodiment ferrite transformation is promoted with Al as an alternative to Si.
- the finish temperature is set to 880 to 1000 ° C.
- the final pass reduction ratio is set to 20% or more
- primary cooling is started in 0.01 to 1.0 seconds after finish rolling. In this primary cooling, cooling is performed to 600 to 750 ° C. at a cooling rate of 30 ° C./second or more. After primary cooling, air cool for 3 to 10 seconds, and after air cooling, perform secondary cooling to 200 ° C.
- the ferrite structure fraction is 90 to 99%
- the martensite grain size is 1 to 10 ⁇ m
- the martensite structure fraction is 1 to 10%
- the steel sheet texture is parallel to the rolling surface.
- C 0.02 to 0.10% C is an important element for improving the strength of the steel sheet.
- the lower limit of the C content is 0.02%.
- a preferable lower limit of the C content is 0.04%.
- the upper limit of C content is 0.10%.
- Si 0.005 to 0.1%
- Si is an element necessary for preliminary deoxidation. Therefore, the lower limit of the Si content is set to 0.005%.
- the upper limit of the Si content is set to 0.1%.
- the Si content is preferably less than 0.1%, more preferably 0.07% or less, and even more preferably 0.05% or less.
- Mn 0.5 to 2.0%
- Mn is an element that contributes to increasing the strength of the steel sheet by improving hardenability and solid solution strengthening.
- the lower limit of the Mn content is 0.5%.
- the upper limit of the Mn content is set to 2.0%.
- P 0.1% or less
- P is an impurity, which is an element that adversely affects workability and weldability and also reduces fatigue characteristics. Therefore, the lower the P content, the better. However, the lower limit may be 0.0005% in view of the dephosphorization cost. If the P content exceeds 0.1%, the adverse effect becomes significant, so the P content is limited to 0.1% or less.
- S 0.01% or less S generates inclusions such as MnS, which are harmful to the isotropic toughness. Therefore, the lower the S content, the better. However, the lower limit may be set to 0.0005% because of the desulfurization cost. If the S content exceeds 0.01%, the adverse effect becomes significant, so the S content is limited to 0.01% or less. When particularly severe low temperature toughness is required, it is preferable to limit the S content to 0.006% or less.
- Al 0.2 to 0.8%
- Al is an important element for the hot-rolled steel sheet according to the present embodiment.
- the lower limit of the Al content is 0.2%.
- the upper limit of the Al content is set to 0.8%.
- N 0.01% or less
- N is an element that forms precipitates with Ti in a temperature range higher than S.
- N content is limited to 0.01% or less.
- Ti 0.01 to 0.11%
- Ti is an element that improves the strength of the steel sheet by precipitation strengthening.
- the lower limit of the Ti content is set to 0.01%.
- the upper limit of Ti content is 0.11%.
- Si and Al are elements that promote ferrite transformation. If Si + Al, which is the sum of the Si content and the Al content, is 0.20% or less, ferrite transformation does not proceed during intermediate air cooling, and the desired ferrite structure fraction cannot be obtained during ROT cooling. On the other hand, when Si + Al is 0.81% or more, the ferrite transformation temperature becomes excessively high and ferrite transformation occurs during rolling, so that the anisotropy of the texture becomes strong. Si + Al is preferably more than 0.20% and not more than 0.60%.
- the hot-rolled steel sheet according to the present embodiment basically contains the above-described chemical components and the balance is made of Fe and impurities. However, one or more selected from Nb, Ca, Mo, and Cr may be further included in the following range in order to reduce manufacturing variation and further improve the strength. In addition, since it is not always necessary to add these chemical elements to the steel sheet, the lower limit is 0%.
- Nb 0.01 to 0.10%
- Nb can increase the strength of the steel sheet by reducing the crystal grain size of the hot-rolled steel sheet and by precipitation strengthening of NbC.
- the Nb content is preferably 0.01% or more.
- the Nb content exceeds 0.10%, the effect is saturated. Therefore, the upper limit of Nb content is 0.10%.
- Ca 0.0005 to 0.0030%
- Ca has the effect of dispersing a large number of fine oxides in the molten steel to refine the structure.
- Ca is an element that improves the hole expansibility of the steel sheet by fixing S in the molten steel as spherical CaS and suppressing the formation of stretched inclusions such as MnS.
- the Ca content is preferably 0.0005% or more.
- the upper limit of the Ca content is set to 0.0030%.
- Mo 0.02 to 0.5%
- Mo is an element effective for precipitation strengthening of ferrite.
- the Mo content is desirably 0.02% or more.
- the upper limit of the Mo content is 0.5%.
- Cr 0.02 to 1.0% Cr is an effective element for improving the strength of the steel sheet.
- the Cr content is preferably 0.02% or more.
- the upper limit of Cr content is 1.0%.
- a composite structure steel that is a steel sheet in which a hard structure such as martensite is dispersed in a ferrite that is soft and excellent in elongation.
- Such a composite structure steel has high elongation while having high strength.
- high strain concentrates in the vicinity of the hard structure and the crack propagation speed is increased, so that there is a drawback that the hole expandability is low.
- the martensite particle size is set to 10 ⁇ m or less and the martensite fraction (area ratio) in the microstructure is 10% or less. Is effective.
- the area ratio of martensite needs to be 1% or more.
- bainite is inferior in elongation and hole expansibility to ferrite, and the strength increase is lower than martensite. Therefore, it is desirable to limit the area ratio of bainite to 5% or less because it is difficult to achieve both elongation and hole expansibility. In the hot-rolled steel sheet according to the present embodiment, it is not necessary to define the area ratio of the structure other than ferrite, martensite, and bainite.
- the steel having the above-described chemical components is continuously cast to obtain a continuous cast slab (hereinafter referred to as slab) (casting process).
- slab a continuous cast slab
- the slab Prior to hot rolling, the slab is heated to 1200 ° C. or higher (heating step).
- the slab Prior to hot rolling, the slab is heated to 1200 ° C. or higher (heating step).
- the slab is heated at less than 1200 ° C., TiC is not sufficiently dissolved in the slab, and Ti required for precipitation strengthening of ferrite is insufficient.
- the heating temperature is 1300 ° C. or higher, the amount of scale generated and the maintenance cost of the heating furnace increase, which is not preferable.
- Rough rolling is performed on the heated slab (rough rolling process), and continuous finish rolling is performed in a finishing mill line in which a plurality of rolling mills are arranged in series (finish rolling process).
- final rolling final rolling reduction is 20% or more
- final finishing rolling finishing temperature FT temperature at the completion of the final pass
- a rolling reduction of 20% or more is required as the rolling reduction of the final pass.
- the martensite becomes coarse and the hole expansibility becomes inferior.
- the finish rolling temperature is less than 880 ° C.
- the recrystallization of austenite does not proceed, the texture of the steel sheet develops, the X-ray random intensity ratio in the ⁇ 211 ⁇ ⁇ 011> orientation parallel to the rolling surface and parallel to the rolling direction is Since it exceeds 3.0, the hole expandability is inferior.
- the finish rolling temperature is higher than 1000 ° C., the crystal grain size of austenite becomes coarse and the dislocation density decreases rapidly, so that the ferrite transformation is significantly delayed. As a result, a ferrite structure fraction of 90% or more cannot be obtained.
- the finish rolling temperature is preferably 900 ° C. or higher.
- primary cooling is performed (primary cooling step). This primary cooling starts between 0.01 and 1.0 seconds after completion of finish rolling.
- water cooling is performed, but in order to complete recrystallization of austenite after rolling, it is necessary to perform air cooling (cooling) for 0.01 seconds or more from the completion of finish rolling to the start of primary cooling.
- air cooling cooling
- the time from the completion of finish rolling to the start of primary cooling is preferably 0.02 seconds or more, more preferably 0.05 seconds or more.
- the air cooling time is long, coarsening of recrystallized austenite crystal grains occurs, ferrite transformation is greatly delayed, and coarse martensite is formed.
- the primary cooling is started within 1.0 seconds after the finish rolling is completed.
- the primary cooling after finish rolling is performed at a cooling rate of 30 ° C./second or more so that the cooling stop temperature is in the temperature range of 600 to 750 ° C.
- intermediate air cooling is performed in this temperature range for 3 to 10 seconds (air cooling process). Since fine austenite has a high crystal grain growth rate, if the cooling rate is less than 30 ° C./second, the grains grow during cooling and the structure becomes coarse. On the other hand, if the cooling rate of primary cooling is too fast, temperature distribution tends to occur in the thickness direction of the steel sheet.
- the cooling rate of the primary cooling is preferably set to 100 ° C./second or less. If the cooling stop temperature and the temperature range for air cooling are less than 600 ° C., the ferrite transformation is delayed, a high ferrite fraction cannot be obtained, and the elongation deteriorates.
- secondary cooling is performed to cool the steel sheet to 200 ° C. or less at a cooling rate of 30 ° C./second or more (secondary cooling step) and winding (winding step).
- the cooling rate of the secondary cooling is less than 30 ° C./second, bainite transformation proceeds and martensite cannot be obtained. In this case, the tensile strength decreases and the elongation becomes inferior.
- the cooling rate of secondary cooling is too fast, a temperature distribution tends to occur in the thickness direction of the steel sheet. If there is a temperature distribution in the plate thickness direction, there is a concern that the grain size of ferrite and martensite will change between the steel plate center portion and the surface layer portion, resulting in large material variations.
- the cooling rate of the secondary cooling is preferably 100 ° C./second or less.
- the cooling stop temperature exceeds 200 ° C., the martensite self-tempering effect occurs.
- self-tempering occurs, the tensile strength decreases and the elongation becomes inferior.
- Table 1 Steel containing the components shown in Table 1 was melted in a converter and formed into a slab having a thickness of 230 mm by continuous casting. Thereafter, the slab was heated to a temperature of 1200 ° C. to 1250 ° C., subjected to rough rolling and finish rolling with a continuous hot rolling device, wound up after ROT cooling, and manufactured a hot-rolled steel sheet.
- Table 2 shows the steel type symbols used, the hot rolling conditions, and the steel plate thickness.
- “FT6” is the temperature at the completion of the final finishing pass
- “Cooling start time” is the time from finish rolling to the start of primary cooling
- Primary cooling is the time from finish rolling to the intermediate air cooling temperature.
- Average cooling rate “intermediate temperature” is the intermediate air cooling temperature after primary cooling
- “intermediate time” is the intermediate air cooling time after primary cooling
- “secondary cooling” is the average cooling rate from intermediate air cooling to winding
- “winding” Take-off temperature” is the temperature after the end of secondary cooling.
- the steel plate thus obtained was subjected to a structural fraction and texture analysis of ferrite, bainite and martensite using an optical microscope.
- the particle size of martensite was also investigated.
- the area ratio was obtained by performing image analysis on the structure photograph obtained with a field of view of 500 ⁇ 500 ⁇ m using an optical microscope after nital corrosion.
- the martensite structure fraction and particle size were determined by image analysis for the structure photograph obtained with a 500 ⁇ 500 ⁇ m field of view using an optical microscope after repeller corrosion.
- the X-ray random intensity ratio in the ⁇ 211 ⁇ ⁇ 011> direction parallel to the rolling surface and parallel to the rolling direction is obtained at the 1/4 thickness portion, which is 1/4 position from the surface in the thickness direction. evaluated.
- the pixel measurement interval is 1/5 or less of the average particle diameter, and is measured in an area where 5000 or more crystal grains can be measured. From the distribution of ODF (Orientation Distribution Function) The X-ray random intensity ratio was measured. An X-ray random intensity ratio of 3.0 or less was accepted.
- the hole expansion rate ⁇ (%) was evaluated by the method specified in ISO 16630.
- Evaluation of the steel sheet appearance was performed by cutting the steel sheet 500 mm in the longitudinal direction at a position of 10 m on the outer periphery of the hot rolled coil, and measuring the area ratio of the scale pattern.
- a scale pattern area ratio of 10% or less was designated as “G: GOOD”.
- B: BAD the case where the area ratio of the scale pattern was more than 10%.
- Table 3 shows the evaluation results of the structure fraction (area ratio), martensite particle size, texture, material, and appearance of each structure.
- the present invention example has a tensile strength of 590 MPa or more, a ferrite structure fraction of 90% or more, a martensite particle size of 10 ⁇ m or less, and a structure fraction of 1% or more and 10% or less.
- the X-ray random intensity ratio in the ⁇ 211 ⁇ ⁇ 011> orientation parallel to the rolling surface and parallel to the rolling direction is 3.0 or less. In other words, all of the examples of the present invention are excellent in the balance between appearance, elongation and hole expansibility.
- No. No. 5 had a finishing temperature of less than 880 ° C., the anisotropy of the steel sheet texture was strong, and the hole expandability was inferior.
- No. No. 16 had an intermediate air cooling time of more than 10 seconds, so that the bainite transformation proceeded and the martensite structure fraction could not be obtained, so that the elongation and hole expansibility were inferior.
- the composition has a predetermined chemical component, the proportion of the structure is 90% or more and 99% or less of the ferrite, and the martensite particle size is 1 ⁇ m or more and 10 ⁇ m or less.
- the rate is 1% or more and 10% or less
- the X-ray random strength ratio in the ⁇ 211 ⁇ ⁇ 011> orientation parallel to the rolling surface and parallel to the rolling direction is 3.0 or less
- the tensile strength is 590 MPa or more.
- a hot-rolled steel sheet is obtained. This hot-rolled steel sheet is excellent in appearance and balance between elongation and hole expansibility.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
また、特許文献1に記載の技術ではSiが0.5%以上添加される。そのため、熱間圧延時に生成したスケールによって、鋼板に筋模様(以下、スケール模様という)が生成するので、優れた外観が得られない。
本発明において、外観に優れるとは、表面のスケール模様の生成が少ないことを示し、伸びと穴拡げ性とのバランスに優れるとは、20%以上の伸びと100%以上の穴拡げ率とを同時に有することを示す。
ミクロ組織がマルテンサイトを含むと、強度が向上するが、穴拡げ性の低下が懸念される。それゆえ、強度を向上させるために、マルテンサイトによる強度向上(変態強化)の代替として、TiやNbの析出強化を利用することが考えられる。しかしながら、TiやNbを含有させると、熱間圧延中に集合組織が形成される。
また、外観の改善ために、スケール模様生成の原因となるSiの代替としてAlを含有させると、粗大なマルテンサイトが形成され、穴拡げ性が劣化する。本発明者らは、これら2つの課題を解決させるためには、変態直前のオーステナイト組織を制御することが重要であることを新たに見出した。
具体的には、仕上圧延の最終パスにおける圧下率を20%以上とし、かつ仕上圧延温度を880℃以上、1000℃以下とすることによって、オーステナイトの再結晶を促進させることができ、これにより、集合組織の改善を図ることができることを見出した。さらに、仕上圧延終了後、0.01秒~1.0秒の間に鋼板の水冷を開始することで、短時間で再結晶を完了させることができ、これにより微細な再結晶オーステナイトを作りこむことができることを見出した。微細な再結晶オーステナイトからの変態では、フェライトの核生成サイトが多く、かつ素早く変態が進む。そのため、上記冷却完了後に空冷を行うことで細かいフェライトが形成され、空冷中に残留するオーステナイトも微細に残存する。その結果、変態後のマルテンサイトを微細化することが可能となる。
本実施形態に係る熱延鋼板は、引張強度590MPa以上の高強度熱延鋼板を対象とする。このような高強度熱延鋼板において、穴拡げ性の向上を実現するためには、そのミクロ組織(金属組織)において、フェライトの組織分率(面積率)を90%以上、マルテンサイトの組織分率(面積率)を10%以下にすることが効果的である。各組織の組織分率及び粒径は、例えば、適切に腐食を行った鋼板の光学顕微鏡写真(視野:500×500μmの視野)で得られた組織写真に対し、画像解析を行って求めることができる。このような組織を得る手段として、例えば特許文献1に示すように、0.5%以上のSiを含有させた鋼板に対し、熱間圧延工程のランアウトテーブル(以下、ROTという)中で空冷(中間空冷)を施し、フェライト変態を促進させる方法が考えられる。しかしながら、SiはSiスケールを起因としたスケール模様を発生させる原因となる。そのため、Siを含有させると、鋼板使用時の外観不良が課題となる。
一方で、Siを添加しない場合にはフェライト変態を促進させるために仕上圧延温度を低温化させる必要が生じる。しかしながら、仕上圧延温度を低温化すると鋼板の集合組織の発達を招く。具体的には、圧延面に平行で、かつ圧延方向に平行な{211}<110>が発達する。このような集合組織が発達すると、塑性変形の異方性が強くなり、穴拡げ性が劣化する。
つまり、Siを添加しない鋼板で伸びと穴拡げ性とのバランスを向上させることは、従来達成できていなかった。
また、仕上圧延において、仕上温度を880~1000℃、最終パスの圧下率を20%以上とし、仕上圧延終了後、0.01~1.0秒の間に一次冷却を開始する。この一次冷却では、30℃/秒以上の冷却速度で600~750℃まで冷却する。一次冷却後、3~10秒空冷し、空冷後、30℃/秒以上の冷却速度で200℃以下まで二次冷却を行い、巻き取る。上述の製造方法により、フェライトの組織分率が90~99%、マルテンサイトの粒径が1~10μmで、マルテンサイトの組織分率が1~10%であり、鋼板集合組織が圧延面に平行で、圧延方向に平行な{211}<011>方位のX線ランダム強度比が3.0以下、引張強度が590MPa以上の熱延鋼板を得ることができる。この熱延鋼板は、外観、及び伸びと穴拡げ性とのバランスに優れる。
まず、化学成分の限定理由について述べる。
Cは鋼板の強度を向上させるために重要な元素である。この効果を得るため、C含有量の下限を0.02%とする。C含有量の好ましい下限は0.04%である。一方で、C含有量が0.10%を超えると靭性が劣化し、鋼板としての基本的な特性が確保できない。そのため、C含有量の上限を0.10%とする。
Siは予備脱酸に必要な元素である。そのため、Si含有量の下限を0.005%とする。一方で、Siは外観不良を引き起こす原因となる元素であるため、Si含有量の上限を0.1%とする。Si含有量は、好ましくは、0.1%未満であり、より好ましくは0.07%以下であり、さらに好ましくは、0.05%以下である。
Mnは焼入れ性向上及び固溶強化によって鋼板の強度上昇に寄与する元素である。目的の強度を得るため、Mn含有量の下限を0.5%とする。しかしながら、Mn含有量が過剰であると靭性の等方性に有害なMnSが生成する。そのため、Mn含有量の上限を2.0%とする。
Pは不純物であり、加工性や溶接性に悪影響を及ぼすとともに、疲労特性も低下させる元素である。そのため、P含有量は低いほど望ましいが、脱燐コストの関係からその下限を0.0005%としてもよい。P含有量が0.1%を超えると、その悪影響が顕著となるため、P含有量を0.1%以下に制限する。
Sは、靭性の等方性に有害なMnS等の介在物を生成させる。そのため、S含有量は低いほど望ましいが、脱硫コストの関係からその下限を0.0005%としてもよい。S含有量が、0.01%を超えるとその悪影響が顕著となるため、S含有量を0.01%以下に制限する。特に厳しい低温靭性が要求される場合には、S含有量を0.006%以下に制限することが好ましい。
Alは本実施形態に係る熱延鋼板に重要な元素である。仕上圧延後のROTでの冷却中にフェライト変態を促進させるために、Al含有量の下限を0.2%とする。しかし、Al含有量が過剰になると、クラスタ状に析出したアルミナが生成され、靭性が劣化する。そのため、Al含有量の上限を0.8%とする。
NはSよりも高い温度域でTiと析出物を形成する元素である。N含有量が過剰であると、Sを固定するのに有効なTiを減少させるばかりでなく、粗大なTi窒化物を形成して鋼板の靭性を劣化させる。したがってN含有を0.01%以下に制限する。
Tiは析出強化により鋼板の強度を向上させる元素である。フェライトを析出強化し、優れた伸びと穴拡げ性とのバランスを得るために、Ti含有量の下限を0.01%とする。しかしながら、Ti含有量が0.11%を超えるとTiNを起因とした介在物が生成し、穴拡げ性が劣化する。そのため、Ti含有量の上限を0.11%とする。
Si及びAlはどちらもフェライト変態を促進させる元素である。Si含有量とAl含有量との合計であるSi+Alが0.20%以下では中間空冷中にフェライト変態が進まず、ROT冷却中に目的のフェライト組織分率を得ることができない。一方、Si+Alが0.81%以上では、フェライト変態温度が過度に高くなり、圧延中にフェライト変態が起こるため、集合組織の異方性が強くなる。Si+Alは、好ましくは、0.20%超、0.60%以下である。
Nbは熱延鋼板の結晶粒径を小さくすること及びNbCの析出強化により鋼板の強度を高めることができる。これらの効果を得る場合、Nb含有量を0.01%以上とすることが好ましい。一方、Nb含有量が0.10%を超えると、その効果は飽和する。そのため、Nb含有量の上限を0.10%とする。
Caは溶鋼中に微細な酸化物を多数分散させ、組織を微細化する効果を有する。また、Caは、溶鋼中のSを球形のCaSとして固定して、MnSなどの延伸介在物の生成を抑制することにより、鋼板の穴拡げ性を向上させる元素である。これらの効果を得る場合、Ca含有量を0.0005%以上にすることが好ましい。一方、Ca含有量が0.0030%を超えてもその効果は飽和するため、Ca含有量の上限を0.0030%とする。
Moはフェライトを析出強化させるのに有効な元素である。この効果を得る場合、Mo含有量を0.02%以上にすることが望ましい。ただし、Mo含有量が過剰になると、スラブの割れ感受性が高まってスラブの取り扱いが困難になる。そのため、Mo含有量の上限を0.5%とする。
Crは鋼板の強度を向上させるのに有効な元素である。この効果を得る場合、Cr含有量を0.02%以上とすることが好ましい。ただし、Cr含有量が過剰になると、伸びが低下する。そのためCr含有量の上限を1.0%とする。
また、ベイナイトは、フェライトに対して伸びと穴拡げ性が劣位で、マルテンサイトよりも強度上昇が低くなる。従って、伸びと穴拡げ性の両立が困難になるという理由で、ベイナイトの面積率は5%以下に制限することが望ましい。本実施形態に係る熱延鋼板において、フェライト、マルテンサイト、ベイナイト以外の組織について、その面積率を規定する必要はない。
なお、より確実にオーステナイトを再結晶させるには、仕上圧延温度は、900℃以上にすることが好ましい。
Claims (3)
- 化学成分が、質量%で、
C :0.02~0.10%、
Si:0.005~0.1%、
Mn:0.5~2.0%、
P :0.1%以下、
S :0.01%以下、
Al:0.2~0.8%、
N :0.01%以下、
Ti:0.01~0.11%、
Nb:0~0.10%、
Ca:0~0.0030%、
Mo:0.02~0.5%、
Cr:0.02~1.0%、
を含有し、残部Feおよび的不純物からなり、
Si含有量と、Al含有量との合計が、0.20%超、0.81%未満であり;
ミクロ組織が、面積率で、90~99%のフェライトと、1~10%のマルテンサイトとを有し、かつベイナイトが5%以下に制限され;
前記マルテンサイトの粒径が1~10μmであり;
鋼板の圧延面に平行で、かつ圧延方向に平行な{211}<011>方位のX線ランダム強度比が3.0以下であり;
引張強度が590MPa以上である;
ことを特徴とする熱延鋼板。 - 前記化学成分が、質量%で
Nb:0.01%~0.10%、
Ca:0.0005~0.0030%、
Mo:0.02~0.5%、
Cr:0.02~1.0%
のうち1種以上を含有する
ことを特徴とする請求項1に記載の熱延鋼板。 - 請求項1又は2に記載の化学成分を有する鋼を連続鋳造することによってスラブを得る鋳造工程と;
前記スラブを1200℃以上の温度域まで加熱する加熱工程と;
加熱された前記スラブに粗圧延を行う粗圧延工程と;
前記粗圧延工程後に、前記スラブを、直列に配置された複数の圧延機を有する仕上圧延機列で、最終パスの圧下率が20%以上、仕上圧延温度が880~1000℃となるように連続仕上圧延して鋼板を得る仕上圧延工程と;
前記仕上圧延工程完了から0.01秒~1.0秒後に開始され、前記鋼板を、30℃/秒以上の冷却速度で600~750℃の温度範囲まで水冷する一次冷却工程と;
前記一次冷却工程後、前記鋼板を、3~10秒間空冷する空冷工程と;
前記空冷工程後、前記鋼板を、30℃/秒以上の冷却速度で200℃以下まで水冷する二次冷却工程と;
前記二次冷却工程後に前記鋼板を巻き取る巻き取り工程と;
を備えることを特徴とする熱延鋼板の製造方法。
Priority Applications (10)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PL14893619T PL3150733T3 (pl) | 2014-05-28 | 2014-05-28 | Blacha stalowa cienka walcowana na gorąco i sposób jej wytwarzania |
CN201480079185.8A CN106460109B (zh) | 2014-05-28 | 2014-05-28 | 热轧钢板及其制造方法 |
US15/313,484 US10513749B2 (en) | 2014-05-28 | 2014-05-28 | Hot-rolled steel sheet and production method of therefor |
BR112016027395A BR112016027395B1 (pt) | 2014-05-28 | 2014-05-28 | chapa de aço laminada a quente e método de produção da mesma |
JP2016523028A JP6191769B2 (ja) | 2014-05-28 | 2014-05-28 | 熱延鋼板及びその製造方法 |
KR1020167032529A KR101914848B1 (ko) | 2014-05-28 | 2014-05-28 | 열연 강판 및 그 제조 방법 |
EP14893619.8A EP3150733B1 (en) | 2014-05-28 | 2014-05-28 | Hot-rolled steel sheet and production method therefor |
ES14893619T ES2793938T3 (es) | 2014-05-28 | 2014-05-28 | Chapa de acero laminada en caliente y método de producción de la misma |
PCT/JP2014/064150 WO2015181911A1 (ja) | 2014-05-28 | 2014-05-28 | 熱延鋼板及びその製造方法 |
MX2016015397A MX2016015397A (es) | 2014-05-28 | 2014-05-28 | Hoja de acero laminada en caliente y metodo de produccion de esta. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2014/064150 WO2015181911A1 (ja) | 2014-05-28 | 2014-05-28 | 熱延鋼板及びその製造方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2015181911A1 true WO2015181911A1 (ja) | 2015-12-03 |
Family
ID=54698292
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2014/064150 WO2015181911A1 (ja) | 2014-05-28 | 2014-05-28 | 熱延鋼板及びその製造方法 |
Country Status (10)
Country | Link |
---|---|
US (1) | US10513749B2 (ja) |
EP (1) | EP3150733B1 (ja) |
JP (1) | JP6191769B2 (ja) |
KR (1) | KR101914848B1 (ja) |
CN (1) | CN106460109B (ja) |
BR (1) | BR112016027395B1 (ja) |
ES (1) | ES2793938T3 (ja) |
MX (1) | MX2016015397A (ja) |
PL (1) | PL3150733T3 (ja) |
WO (1) | WO2015181911A1 (ja) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018179388A1 (ja) * | 2017-03-31 | 2018-10-04 | 新日鐵住金株式会社 | 熱間圧延鋼板 |
CN109642278A (zh) * | 2016-08-18 | 2019-04-16 | 新日铁住金株式会社 | 热轧钢板 |
WO2019088104A1 (ja) * | 2017-10-30 | 2019-05-09 | 新日鐵住金株式会社 | 熱延鋼板及びその製造方法 |
EP3556887A4 (en) * | 2016-12-19 | 2019-10-23 | Posco | HOT-ROLLED STEEL SHEET FOR ELECTRIC RESISTANCE-WELDED STEEL PIPE HAVING EXCELLENT WELDABILITY AND METHOD FOR MANUFACTURING THE SAME |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR102374941B1 (ko) * | 2017-11-24 | 2022-03-16 | 닛폰세이테츠 가부시키가이샤 | 열연 강판 및 그 제조 방법 |
CN114086073A (zh) * | 2021-11-19 | 2022-02-25 | 安徽工业大学 | 一种热轧高强结构钢的生产方法 |
WO2024115602A1 (en) * | 2022-11-29 | 2024-06-06 | Tata Steel Ijmuiden B.V. | Method for reducing cracking during continuous casting of aluminium alloyed steel |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1161327A (ja) * | 1997-08-06 | 1999-03-05 | Nippon Steel Corp | 耐衝突安全性と成形性に優れた自動車用高強度鋼板とその製造方法 |
JP2005120438A (ja) * | 2003-10-17 | 2005-05-12 | Nippon Steel Corp | 延性及び化成処理性に優れた高強度熱延鋼板及びその製造方法 |
JP2014037594A (ja) * | 2012-08-20 | 2014-02-27 | Nippon Steel & Sumitomo Metal | 熱延鋼板 |
Family Cites Families (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA2283924C (en) | 1997-03-17 | 2006-11-28 | Nippon Steel Corporation | Dual-phase type high-strength steel sheets having high impact energy absorption properties and a method of producing the same |
DE60045303D1 (de) * | 1999-09-29 | 2011-01-13 | Jfe Steel Corp | Stahlblech und verfahren zu dessen herstellung |
JP3990553B2 (ja) | 2000-08-03 | 2007-10-17 | 新日本製鐵株式会社 | 形状凍結性に優れた高伸びフランジ性鋼板およびその製造方法 |
US7070673B2 (en) * | 2002-07-02 | 2006-07-04 | United Technologies Corporation | Method for repairing loose molded-in bushings |
JP4180909B2 (ja) | 2002-12-26 | 2008-11-12 | 新日本製鐵株式会社 | 穴拡げ性、延性及び化成処理性に優れた高強度熱延鋼板及びその製造方法 |
DE60324333D1 (de) | 2002-12-26 | 2008-12-04 | Nippon Steel Corp | Dünnes stahlblech mit hoher festigkeit und hervorragender lochdehnbarkeit, biegbarkeit sowie hervorragenden chemischen behandlungseigenschaften und herstellungsverfahren dafür |
JP4430444B2 (ja) | 2004-03-26 | 2010-03-10 | 新日本製鐵株式会社 | 形状凍結性に優れた低降伏比型高強度熱延鋼板とその製造方法 |
JP4238153B2 (ja) | 2004-02-02 | 2009-03-11 | 新日本製鐵株式会社 | 均一外観性に優れた高強度電気亜鉛めっき鋼板およびその製造方法 |
JP4384523B2 (ja) | 2004-03-09 | 2009-12-16 | 新日本製鐵株式会社 | 形状凍結性に極めて優れた低降伏比型高強度冷延鋼板およびその製造方法 |
JP5000281B2 (ja) | 2006-12-05 | 2012-08-15 | 新日鐵住金ステンレス株式会社 | 加工性に優れた高強度ステンレス鋼板およびその製造方法 |
JP4840270B2 (ja) | 2007-06-29 | 2011-12-21 | 住友金属工業株式会社 | 熱延鋼板およびその製造方法 |
JP5740847B2 (ja) | 2009-06-26 | 2015-07-01 | Jfeスチール株式会社 | 高強度溶融亜鉛めっき鋼板およびその製造方法 |
JP4811528B2 (ja) | 2009-07-28 | 2011-11-09 | Jfeスチール株式会社 | 高強度冷延鋼板およびその製造方法 |
JP5499664B2 (ja) | 2009-11-30 | 2014-05-21 | 新日鐵住金株式会社 | 疲労耐久性に優れた引張最大強度900MPa以上の高強度冷延鋼板及びその製造方法、並びに、高強度亜鉛めっき鋼板及びその製造方法 |
BR112012022573B1 (pt) | 2010-03-10 | 2018-07-24 | Nippon Steel & Sumitomo Metal Corp | chapa de aço laminada a quente de alta resistência e método de produção da mesma. |
JP2011184788A (ja) * | 2010-03-11 | 2011-09-22 | Nippon Steel Corp | 伸びと穴拡げ性のバランスに優れた鋼板及びその製造方法 |
JP5533144B2 (ja) | 2010-03-31 | 2014-06-25 | 新日鐵住金株式会社 | 溶融めっき冷延鋼板およびその製造方法 |
WO2011142356A1 (ja) | 2010-05-10 | 2011-11-17 | 新日本製鐵株式会社 | 高強度鋼板及びその製造方法 |
EA022435B1 (ru) | 2010-08-23 | 2015-12-30 | Ниппон Стил Энд Сумитомо Метал Корпорейшн | Холоднокатаный стальной лист и способ его получения |
WO2012128228A1 (ja) | 2011-03-18 | 2012-09-27 | 新日本製鐵株式会社 | 熱延鋼板及びその製造方法 |
MX2013011750A (es) | 2011-04-13 | 2013-11-04 | Nippon Steel & Sumitomo Metal Corp | Laminas de acero laminadas en frio, de alta resistencia, que tienen deformabilidad local excelente y metodo de fabricacion de las mismas. |
JP5712771B2 (ja) | 2011-04-28 | 2015-05-07 | 新日鐵住金株式会社 | 圧延直角方向のヤング率に優れた鋼板及びその製造方法 |
CN103562428B (zh) | 2011-05-25 | 2015-11-25 | 新日铁住金株式会社 | 冷轧钢板及其制造方法 |
JP5327301B2 (ja) | 2011-09-15 | 2013-10-30 | Jfeスチール株式会社 | 延性と深絞り性に優れた高強度鋼板およびその製造方法 |
WO2013065346A1 (ja) | 2011-11-01 | 2013-05-10 | Jfeスチール株式会社 | 曲げ特性と低温靭性に優れた高強度熱延鋼板およびその製造方法 |
KR101617115B1 (ko) | 2012-01-05 | 2016-04-29 | 신닛테츠스미킨 카부시키카이샤 | 열연 강판 및 그 제조 방법 |
JP5825189B2 (ja) | 2012-04-24 | 2015-12-02 | 新日鐵住金株式会社 | 伸びと穴拡げ性と低温靭性に優れた高強度熱延鋼板及びその製造方法 |
US9211216B2 (en) * | 2012-06-29 | 2015-12-15 | Kimberly-Clark Worldwide, Inc. | Tampon method of manufacture |
JP6359534B2 (ja) | 2012-08-03 | 2018-07-18 | タタ、スティール、アイモイデン、ベスローテン、フェンノートシャップTata Steel Ijmuiden Bv | 熱間圧延鋼ストリップを製造するためのプロセスおよびそれにより製造された鋼ストリップ |
PL2896710T3 (pl) * | 2012-12-19 | 2019-02-28 | Nippon Steel & Sumitomo Metal Corporation | Blacha stalowa cienka walcowana na gorąco i sposób jej wytwarzania |
MX2018006061A (es) * | 2015-11-19 | 2018-09-21 | Nippon Steel & Sumitomo Metal Corp | Lamina de acero laminada en caliente de alta resistencia y metodo de fabricacion de la misma. |
-
2014
- 2014-05-28 JP JP2016523028A patent/JP6191769B2/ja active Active
- 2014-05-28 BR BR112016027395A patent/BR112016027395B1/pt not_active IP Right Cessation
- 2014-05-28 CN CN201480079185.8A patent/CN106460109B/zh active Active
- 2014-05-28 KR KR1020167032529A patent/KR101914848B1/ko active IP Right Grant
- 2014-05-28 US US15/313,484 patent/US10513749B2/en active Active
- 2014-05-28 ES ES14893619T patent/ES2793938T3/es active Active
- 2014-05-28 EP EP14893619.8A patent/EP3150733B1/en active Active
- 2014-05-28 PL PL14893619T patent/PL3150733T3/pl unknown
- 2014-05-28 WO PCT/JP2014/064150 patent/WO2015181911A1/ja active Application Filing
- 2014-05-28 MX MX2016015397A patent/MX2016015397A/es unknown
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1161327A (ja) * | 1997-08-06 | 1999-03-05 | Nippon Steel Corp | 耐衝突安全性と成形性に優れた自動車用高強度鋼板とその製造方法 |
JP2005120438A (ja) * | 2003-10-17 | 2005-05-12 | Nippon Steel Corp | 延性及び化成処理性に優れた高強度熱延鋼板及びその製造方法 |
JP2014037594A (ja) * | 2012-08-20 | 2014-02-27 | Nippon Steel & Sumitomo Metal | 熱延鋼板 |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109642278B (zh) * | 2016-08-18 | 2020-12-25 | 日本制铁株式会社 | 热轧钢板 |
CN109642278A (zh) * | 2016-08-18 | 2019-04-16 | 新日铁住金株式会社 | 热轧钢板 |
US11255005B2 (en) | 2016-08-18 | 2022-02-22 | Nippon Steel Corporation | Hot-rolled steel sheet |
EP3502292A4 (en) * | 2016-08-18 | 2020-03-04 | Nippon Steel Corporation | HOT-ROLLED STEEL SHEET |
US11535907B2 (en) | 2016-12-19 | 2022-12-27 | Posco Co., Ltd | Hot rolled steel plate for electric resistance welded steel pipe having excellent weldability, and manufacturing method thereof |
EP3556887A4 (en) * | 2016-12-19 | 2019-10-23 | Posco | HOT-ROLLED STEEL SHEET FOR ELECTRIC RESISTANCE-WELDED STEEL PIPE HAVING EXCELLENT WELDABILITY AND METHOD FOR MANUFACTURING THE SAME |
JPWO2018179388A1 (ja) * | 2017-03-31 | 2019-11-07 | 日本製鉄株式会社 | 熱間圧延鋼板 |
US10900100B2 (en) | 2017-03-31 | 2021-01-26 | Nippon Steel Corporation | Hot rolled steel sheet |
WO2018179388A1 (ja) * | 2017-03-31 | 2018-10-04 | 新日鐵住金株式会社 | 熱間圧延鋼板 |
EP3604586A4 (en) * | 2017-03-31 | 2020-08-12 | Nippon Steel Corporation | HOT ROLLED STEEL SHEET |
JPWO2019088104A1 (ja) * | 2017-10-30 | 2020-04-16 | 日本製鉄株式会社 | 熱延鋼板及びその製造方法 |
TWI688665B (zh) * | 2017-10-30 | 2020-03-21 | 日商日本製鐵股份有限公司 | 熱軋鋼板及其製造方法 |
CN110785507B (zh) * | 2017-10-30 | 2021-07-30 | 日本制铁株式会社 | 热轧钢板及其制造方法 |
US11198929B2 (en) | 2017-10-30 | 2021-12-14 | Nippon Steel Corporation | Hot rolled steel sheet and method for producing same |
CN110785507A (zh) * | 2017-10-30 | 2020-02-11 | 日本制铁株式会社 | 热轧钢板及其制造方法 |
WO2019088104A1 (ja) * | 2017-10-30 | 2019-05-09 | 新日鐵住金株式会社 | 熱延鋼板及びその製造方法 |
Also Published As
Publication number | Publication date |
---|---|
US20170159149A1 (en) | 2017-06-08 |
CN106460109B (zh) | 2019-01-29 |
EP3150733A1 (en) | 2017-04-05 |
ES2793938T3 (es) | 2020-11-17 |
JPWO2015181911A1 (ja) | 2017-04-20 |
CN106460109A (zh) | 2017-02-22 |
BR112016027395B1 (pt) | 2020-05-05 |
KR101914848B1 (ko) | 2018-11-02 |
EP3150733B1 (en) | 2020-04-22 |
US10513749B2 (en) | 2019-12-24 |
KR20160145794A (ko) | 2016-12-20 |
JP6191769B2 (ja) | 2017-09-06 |
PL3150733T3 (pl) | 2020-08-24 |
MX2016015397A (es) | 2017-02-22 |
EP3150733A4 (en) | 2017-11-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5821861B2 (ja) | 外観に優れ、伸びと穴拡げ性のバランスに優れた高強度熱延鋼板及びその製造方法 | |
JP6191769B2 (ja) | 熱延鋼板及びその製造方法 | |
JP5821912B2 (ja) | 高強度冷延鋼板およびその製造方法 | |
JP6354271B2 (ja) | 低温靭性と均一伸びと穴拡げ性に優れた引張強度780MPa以上の高強度熱延鋼板及びその製造方法 | |
JP6760407B2 (ja) | 熱間圧延鋼板及びその製造方法 | |
JP6682967B2 (ja) | 厚鋼板およびその製造方法 | |
WO2016135794A1 (ja) | 高強度冷延鋼板およびその製造方法 | |
JP2005290547A (ja) | 延性および伸びフランジ性に優れた高炭素熱延鋼板およびその製造方法 | |
WO2014097559A1 (ja) | 低降伏比高強度冷延鋼板およびその製造方法 | |
JP6260198B2 (ja) | 伸びと穴拡げ性のバランスに優れた高強度熱延鋼板及びその製造方法 | |
JP6460258B2 (ja) | 高強度熱延鋼板及びその製造方法 | |
WO2019088104A1 (ja) | 熱延鋼板及びその製造方法 | |
WO2013088666A1 (ja) | 高降伏比高強度冷延鋼板とその製造方法 | |
JP2009001909A (ja) | 高強度冷延鋼板の製造方法 | |
JP4696853B2 (ja) | 加工性に優れた高炭素冷延鋼板の製造方法および高炭素冷延鋼板 | |
JP5483562B2 (ja) | 伸びと伸びフランジ性のバランスに優れた高強度冷延鋼板 | |
JP6822604B2 (ja) | 薄鋼板およびその製造方法 | |
WO2020080339A1 (ja) | 薄鋼板およびその製造方法 | |
TWI531662B (zh) | 熱軋鋼板及其製造方法 | |
JP2016211047A (ja) | 熱延鋼板およびその製造方法 | |
WO2018168618A1 (ja) | 高強度冷延鋼板とその製造方法 | |
KR102412013B1 (ko) | 열연 강판 | |
KR101657835B1 (ko) | 프레스 성형성이 우수한 고강도 열연강판 및 그 제조방법 |
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: 14893619 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2016523028 Country of ref document: JP Kind code of ref document: A |
|
ENP | Entry into the national phase |
Ref document number: 20167032529 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 15313484 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: IDP00201608041 Country of ref document: ID Ref document number: MX/A/2016/015397 Country of ref document: MX |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
REEP | Request for entry into the european phase |
Ref document number: 2014893619 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2014893619 Country of ref document: EP |
|
REG | Reference to national code |
Ref country code: BR Ref legal event code: B01A Ref document number: 112016027395 Country of ref document: BR |
|
ENP | Entry into the national phase |
Ref document number: 112016027395 Country of ref document: BR Kind code of ref document: A2 Effective date: 20161122 |