WO2022139309A1 - 가공성이 우수한 냉연강판 및 그 제조방법 - Google Patents
가공성이 우수한 냉연강판 및 그 제조방법 Download PDFInfo
- Publication number
- WO2022139309A1 WO2022139309A1 PCT/KR2021/019101 KR2021019101W WO2022139309A1 WO 2022139309 A1 WO2022139309 A1 WO 2022139309A1 KR 2021019101 W KR2021019101 W KR 2021019101W WO 2022139309 A1 WO2022139309 A1 WO 2022139309A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- steel sheet
- rolled steel
- less
- cold
- hot
- Prior art date
Links
- 239000010960 cold rolled steel Substances 0.000 title claims description 62
- 238000004519 manufacturing process Methods 0.000 title claims description 37
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 100
- 239000010959 steel Substances 0.000 claims abstract description 100
- 239000012535 impurity Substances 0.000 claims abstract description 10
- 238000001953 recrystallisation Methods 0.000 claims description 41
- 238000000137 annealing Methods 0.000 claims description 28
- 238000000034 method Methods 0.000 claims description 27
- 238000005096 rolling process Methods 0.000 claims description 19
- 238000005097 cold rolling Methods 0.000 claims description 13
- 238000007747 plating Methods 0.000 claims description 11
- 230000002787 reinforcement Effects 0.000 claims description 11
- 238000005728 strengthening Methods 0.000 claims description 9
- 238000005098 hot rolling Methods 0.000 claims description 8
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- 239000013078 crystal Substances 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 4
- 229910052758 niobium Inorganic materials 0.000 claims description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims description 4
- 238000004804 winding Methods 0.000 claims description 4
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 238000009713 electroplating Methods 0.000 claims description 3
- 229910052718 tin Inorganic materials 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 230000000052 comparative effect Effects 0.000 description 74
- 238000012545 processing Methods 0.000 description 69
- 238000011161 development Methods 0.000 description 56
- 230000018109 developmental process Effects 0.000 description 56
- 239000011572 manganese Substances 0.000 description 26
- 230000000704 physical effect Effects 0.000 description 10
- 239000006104 solid solution Substances 0.000 description 10
- 239000000463 material Substances 0.000 description 9
- 230000003014 reinforcing effect Effects 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 238000003754 machining Methods 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 238000005482 strain hardening Methods 0.000 description 6
- 230000032683 aging Effects 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- 238000007792 addition Methods 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- 238000011084 recovery Methods 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 230000001376 precipitating effect Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 230000035882 stress Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 230000003679 aging effect Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/01—Layered products comprising a layer of metal all layers being exclusively metallic
- B32B15/013—Layered products comprising a layer of metal all layers being exclusively metallic one layer being formed of an iron alloy or steel, another layer being formed of a metal other than iron or aluminium
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/008—Heat treatment of ferrous alloys containing Si
-
- 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
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0236—Cold rolling
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
- C21D8/0273—Final recrystallisation annealing
-
- 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
- C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
- C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
- C21D8/0436—Cold rolling
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
-
- 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
- C22C38/40—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
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
Definitions
- One embodiment of the present invention relates to a cold-rolled steel sheet having excellent workability and a method for manufacturing the same. More particularly, it relates to a cold-rolled steel sheet having excellent workability before and after machining, and thus making it easy to make parts in the middle stage of machining, and a method for manufacturing the same.
- Cold-rolled steel sheet is manufactured and used as a final structure through several stages of mechanical or thermal processing after manufacturing.
- mechanical processing ductility is lowered and machinability deteriorates. Therefore, after primary mechanical processing, machinability is improved again through thermal processing in the intermediate stage, and then the final shape is obtained through secondary mechanical processing in many cases.
- the mechanical properties immediately after manufacturing the cold rolled steel sheet but also the mechanical properties after mechanical processing and thermal processing are important.
- ductility for primary mechanical processing is required, and after thermal processing, not only ductility for secondary mechanical processing, but also final strength after mechanical processing must be secured.
- ductility may decrease due to aging from thermal processing to final processing, low aging characteristics of a certain level or higher are required to secure sufficient workability.
- solid solution strengthening is the simplest method for increasing strength, and is a method of adding an alloying element capable of solid solution.
- Solid solution strengthening can be effectively used to secure the strength of the final product because the effect is maintained even after thermal processing during processing.
- substitution-type elements such as Mn and Si, which are generally used to obtain the desired effect, have to be added in large amounts to reduce economic feasibility, and in the case of interstitial elements such as C and N, there is an increase in the tendency to cause deterioration of workability due to aging. .
- Precipitation strengthening is a method of increasing strength through fine precipitates that are stable at high temperatures.
- a precipitate that is very stable at high temperature interferes with recrystallization, a very high temperature or a long time is required to cause recrystallization, which is not suitable.
- a method of manufacturing high-strength steel by finely precipitating TiN, NbC, and TiC using Ti and Nb, which has a high recrystallization temperature improvement effect, and performing recovery annealing has been proposed. high and economical.
- hard phase control it is a method of forming a metastable phase to a desired degree mainly through a fast cooling rate when manufacturing a steel sheet.
- a method of securing high strength of 800 MPa or more by utilizing a hard phase has been proposed. This method is difficult to maintain during recrystallization, and in order to obtain a phase after recrystallization, the cooling rate during thermal processing also requires precise control, so it is difficult to utilize it for thermal processing.
- the formability is significantly lowered.
- An embodiment of the present invention is to provide a cold-rolled steel sheet excellent in workability and a method for manufacturing the same. More specifically, it is an object of the present invention to provide a cold-rolled steel sheet and a manufacturing method thereof, which are excellent in both workability before and after machining, so that it is easy to make parts in the middle stage of machining.
- the cold-rolled steel sheet having excellent workability is C: 0.012 to 0.060% by weight, Si: 0.03% or less (excluding 0%), Mn: 0.1 to 0.4%, Al: 0.015 to 0.050% , P: 0.015% or less (excluding 0%), S: 0.015% or less (excluding 0%), and N: 0.006% or less (excluding 0%), the balance being Fe and other unavoidable impurities includes
- the cold-rolled steel sheet having excellent workability according to an embodiment of the present invention may have a reinforcing index defined by the following Equation 1 of 1.0 to 3.0.
- the cold-rolled steel sheet having excellent workability according to an embodiment of the present invention may have a grain aspect ratio of 1.25 to 2.50 defined by Equation 2 below.
- Grain aspect ratio (average grain diameter in rolling direction) / (average grain diameter in thickness direction)
- the cold-rolled steel sheet having excellent workability according to an embodiment of the present invention may have a recrystallization area ratio of 3% or less.
- the cold-rolled steel sheet having excellent workability according to an embodiment of the present invention may have an average grain size of 8 to 12 ⁇ m.
- the cold-rolled steel sheet having excellent workability has Cu: 0.003% or less, Nb: 0.01% by weight or less, Sb: 0.03% by weight or less, Sn: 0.03% by weight or less, Ni: 0.03% by weight or less, Cr: 0.03 wt% or less, Ti: 0.01 wt% or less, and Mo: 0.03 wt% or less may further include one or more.
- the cold-rolled steel sheet having excellent workability according to an embodiment of the present invention may have a dislocation density of 2.5X10 15 /m 2 or less.
- the plated steel sheet according to an embodiment of the present invention includes a cold-rolled steel sheet and a plating layer positioned on one or both surfaces of the cold-rolled steel sheet.
- the method for manufacturing a cold-rolled steel sheet having excellent workability is C: 0.012 to 0.060% by weight, Si: 0.03% or less (excluding 0%), Mn: 0.1 to 0.4%, Al: 0.015 to 0.050%, P: 0.015% or less (excluding 0%), S: 0.015% or less (excluding 0%), and N: 0.006% or less (excluding 0%), the balance being Fe and Preparing a hot-rolled steel sheet by hot-rolling a slab containing other unavoidable impurities and having a reinforcing index of 1.0 to 3.0 defined by Equation 1 below; manufacturing a hot-rolled steel sheet by hot-rolling the slab; winding the hot-rolled steel sheet at 600 to 700°C; Cold rolling the wound hot-rolled steel sheet at a reduction ratio of 20 to 60% to prepare a cold-rolled steel sheet, and annealing the cold-rolled steel sheet at a temperature of 400 to 580°C.
- the step of heating the slab at 1150° C. or higher may be further included.
- hot finish rolling may be performed at Ar 3 or higher.
- the step of temper rolling the annealing plate at a reduction ratio of 0.4 to 2.0% may be further included.
- a method of manufacturing a plated steel sheet according to an embodiment of the present invention includes manufacturing a cold rolled steel sheet; and hot-dip plating or electroplating on one or both surfaces of the cold-rolled steel sheet to form a plating layer.
- a cold-rolled steel sheet for processing that is easy to mechanically process the steel sheet itself, further increases ductility after thermal processing, and has appropriate strength, so that it is easy to perform additional mechanical processing.
- first, second and third etc. are used to describe, but are not limited to, various parts, components, regions, layers and/or sections. These terms are used only to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, a first part, component, region, layer or section described below may be referred to as a second part, component, region, layer or section without departing from the scope of the present invention.
- % means weight %, and 1 ppm is 0.0001 weight %.
- the meaning of further including the additional element means that the remaining iron (Fe) is included by replacing the additional amount of the additional element.
- One embodiment of the present invention relates to a cold-rolled steel sheet used as various structural materials after forming through mechanical and thermal processing. A certain level of strength must be secured. To this end, it is necessary to simultaneously consider changes in physical properties due to mechanical processing and thermal processing as well as the physical properties of the initial material to facilitate step-by-step processing while satisfying the final physical properties.
- a cold rolled steel sheet having the above target physical properties can be manufactured by optimizing the types of alloy elements, their contents, and manufacturing conditions, and led to the present invention.
- the cold-rolled steel sheet having excellent workability is C: 0.012 to 0.060% by weight, Si: 0.03% or less (excluding 0%), Mn: 0.1 to 0.4%, Al: 0.015 to 0.050% , P: 0.015% or less (excluding 0%), S: 0.015% or less (excluding 0%), and N: 0.006% or less (excluding 0%), the balance being Fe and other unavoidable impurities includes
- the component composition of the cold-rolled steel sheet provided in an embodiment of the present invention will be described in detail.
- the content of each component means wt%.
- C When the content of C is low, it is difficult to use as a structural material due to low strength, and in order to excessively lower the content, a refining process is additionally required to decrease productivity, so it may be included in 0.012% by weight or more.
- C can effectively increase the strength even with a small content, but when it is excessive, the workability can be greatly reduced, so the upper limit thereof can be limited to 0.060% by weight or less. More specifically, C may be included in an amount of 0.0035 wt% or less. More specifically, C may be included in an amount of 0.0130 to 0.0550 wt%.
- Si is an element that can be used as a decarburization agent and cannot be completely excluded because it can contribute to the improvement of strength by solid solution strengthening. However, if it is excessive, Si-based oxide may be generated on the surface during annealing, which may cause defects during plating, thereby reducing plating properties. Therefore, in consideration of this, the upper limit may be limited to 0.03 wt% or less. More specifically, Si may be included in an amount of 0.015 wt%. More specifically, Si may be included in an amount of 0.005 to 0.015 wt%.
- Mn is an element that prevents hot shortness due to solid solution S by combining with solid solution S in steel and precipitating as MnS. In order to achieve this effect, it may be included in an amount of 0.1 wt % or more. In addition, it has the effect of increasing the strength of steel together with C by being dissolved in the steel. However, if excessive, the workability of the steel is deteriorated, so it can be limited to 0.4 wt% or less. More specifically, Mn may be included in an amount of 0.150 to 0.390 wt%.
- the correlation between C and Mn content is important for securing strength and workability. It was found that desired strength and workability can be obtained when the reinforcement index defined by the following Relation 1 as an index indicating the reinforcement effect is 1.000 to 3.000.
- the reinforcement index may be 1.500 to 2.700.
- Al is an element with a very large deoxidation effect, and by reacting with N in steel to precipitate AlN, the formability due to solid solution N is prevented from being deteriorated. Therefore, it may contain 0.015 wt% or more of Al. However, when a large amount is added, since the ductility is rapidly reduced, the content may be limited to 0.05 wt% or less. More specifically, it may contain 0.020 to 0.048 wt% of Al.
- P in a certain amount does not significantly reduce the ductility of the steel and is an element that can increase the strength. However, when added in excess of 0.015 wt%, it segregates at grain boundaries to excessively harden the steel and decrease the elongation, so it is limited to 0.015 wt% or less can do. More specifically, P may be included in an amount of 0.015% by weight or less. More specifically, P may be included in an amount of 0.0010 to 0.0100 wt%.
- the upper limit of S can be limited to 0.015% by weight. More specifically, S may include 0.0010 to 0.0100 wt%.
- N is contained as an unavoidable element in steel, but N present in a solid solution causes aging and greatly reduces workability. It is preferable to limit the upper limit to 0.0060% by weight or less in order to minimize deterioration of ductility due to the occurrence of aging. More specifically, N may be included in an amount of 0.0035 wt% or less. More specifically, it may include 0.0010 to 0.0050 wt% of N.
- the cold-rolled steel sheet having excellent workability according to an embodiment of the present invention is Cu: 0.003% or less, Nb: 0.01 wt% or less, Sb: 0.03 wt% or less, Sn: 0.03 wt% or less Ni: 0.03 wt% or less, Cr: 0.03 Weight % or less and Mo: 0.03 wt % or less may further include one or more.
- the remainder preferably includes Fe and unavoidable impurities, and the steel of the present invention does not exclude the addition of other compositions.
- the unavoidable impurities may be unintentionally mixed from raw materials or the surrounding environment in a normal steel manufacturing process, and this cannot be excluded.
- the unavoidable impurities can be understood by those skilled in the art of steel manufacturing.
- the cold-rolled steel sheet having excellent workability according to an embodiment of the present invention may have a grain aspect ratio of 1.25 to 2.50 defined by Equation 2 below.
- Grain aspect ratio (average grain diameter in rolling direction) / (average grain diameter in thickness direction)
- the average grain diameter in the rolling direction can be obtained by dividing the number of grains existing in the corresponding length with respect to the rolling direction of any length.
- the average grain diameter in the thickness direction can also be obtained by dividing the number of grains present with respect to the thickness of the steel sheet.
- the grain aspect ratio is too small, it is difficult to secure the desired strength and the recrystallization driving force is small, so recrystallization may be difficult during heat treatment. If the grain aspect ratio is too large, the difference in workability between the rolling direction and the rolling right angle direction is excessive, which may cause a problem in that the formability deteriorates. More specifically, the grain aspect ratio may be 1.30 to 2.00.
- the cold-rolled steel sheet having excellent workability may have a dislocation density of 2.50X10 15 /m 2 or less.
- the dislocation density can be measured through X-ray diffraction (XRD). If the dislocation density is too high, cracks may occur during machining. More specifically, the dislocation density may be 1.00 to 2.00 X10 15 /m 2 .
- the cold-rolled steel sheet having excellent workability may have a recrystallization area ratio of 3% or less.
- recrystallization and non-recrystallization are distinguished through optical observation through confirmation of newly nucleated and grown crystal grains from the stretched tissue by rolling.
- the recrystallization area ratio can be measured based on a plane parallel to the rolling plane (ND plane) of the steel sheet. If the area ratio is too high, the strength is lowered and recrystallization may not occur in the recrystallized region due to insufficient recrystallization driving force after processing. More specifically, the recrystallization area ratio may be 2.5% or less.
- the cold-rolled steel sheet having excellent workability may have an average grain size of 8.0 to 12.0 ⁇ m. If the average grain size is too low and small, a problem of excessively high strength may occur. If the average grain size is too large, the local material deviation is large and defects may occur during machining.
- the average grain size can be measured based on a plane parallel to the rolling plane (ND plane), and can be determined by measuring the diameter of the circle with respect to a circle having the same area as the crystal grain. More specifically, the average grain size may be 8.3 to 11.5 ⁇ m.
- the cold-rolled steel sheet according to an embodiment of the present invention is excellent in strength and workability at the same time, and, at the same time, is excellent in strength and workability even after processing.
- the yield strength before processing may be 650.0 MPa or less, and the elongation may be 7.0% or more. More specifically, the yield strength before processing may be 450.0 to 650.0 MPa, and the elongation may be 7.5 to 12.0%.
- the yield strength after processing may be 180.0 MPa or more, and the elongation may be 25.0% or more. More specifically, the yield strength after processing may be 180.0 to 250.0 MPa, and the elongation may be 25.0 to 35.0%.
- the processing may be a processing in which the temperature is raised at a rapid rate of 50°C/sec to 740°C after mechanical processing with 20% elongation, and then slowly cooled to 25°C at -5°C/sec.
- the plated steel sheet according to an embodiment of the present invention includes a cold-rolled steel sheet and a plating layer positioned on one or both surfaces of the cold-rolled steel sheet.
- a method of manufacturing a cold-rolled steel sheet having excellent workability includes the steps of: manufacturing a hot-rolled steel sheet by hot rolling a slab; winding the hot-rolled steel sheet; It includes the steps of manufacturing a cold-rolled steel sheet by cold rolling the hot-rolled steel sheet and annealing the cold-rolled steel sheet.
- a slab is hot-rolled to manufacture a hot-rolled steel sheet.
- the alloy composition of the slab is the same as that of the cold-rolled steel sheet described above, the overlapping description will be omitted. Since the alloy composition does not substantially change during the cold-rolled steel sheet manufacturing process, the alloy composition of the slab and the cold-rolled steel sheet is substantially the same.
- the slab may be reheated to a temperature of 1150° C. or higher before hot rolling. Since most of the precipitates present in the steel must be re-dissolved, a temperature of 1150° C. or higher may be required. More specifically, it may be heated to 1200° C. or higher in order to well dissolve the precipitate.
- a hot-rolled steel sheet is manufactured by hot finish rolling the annealed slab at a temperature of Ar 3 or higher.
- the reason for limiting the hot rolling finishing temperature to Ar 3 or higher is to perform rolling in the austenite single phase region.
- Ar 3 temperature may be calculated by the following formula.
- Ar 3 910-(310 ⁇ [C])-(80 ⁇ [Mn])-(20 ⁇ [Cu])-(15 ⁇ [Cr])-(55 ⁇ [Ni])-(80 ⁇ [Mo] ])-(0.35 ⁇ (25.4-8))
- [C], [Mn], [Cu], [Cr], [Ni] and [Mo] are the contents (% by weight) of C, Mn, Cu, Cr, Ni and Mo in the steel sheet, respectively. If not included, it is counted as 0.
- the finish rolling temperature may be 900° C. or higher.
- the hot-rolled steel sheet is wound at 600 to 700°C.
- the size of the crystal grains of the hot-rolled steel sheet changes according to the coiling temperature. When the temperature is low, the grains are fine, and when the temperature is high, the grains are coarse.
- the size of the grain size of the hot-rolled steel sheet is important. In the present invention, since complete recrystallization does not occur during the annealing process after cold rolling, the grain size of the hot-rolled steel sheet directly affects the properties of the final steel sheet. In order to obtain the desired workability and strength of the steel sheet, it is preferable to control the coiling temperature of the hot-rolled steel sheet to 600.0 to 700.0 °C. More specifically, the coiling temperature may be 610.0 to 690.0 °C.
- the hot-rolled steel sheet is cold-rolled.
- a cold rolled steel sheet is manufactured by cold rolling at a reduction ratio of 20.0 to 60.0%.
- the reduction ratio not only determines the final thickness of the cold rolled steel sheet, but can also increase the strength of the steel sheet by work hardening during cold rolling.
- a cold reduction ratio of 20% or more is required.
- it is excessively high processing is difficult due to high strength, or the strength is greatly reduced by promoting recrystallization during annealing.
- the annealing temperature should be further lowered, but if it is excessively lower than the annealing temperature of a conventional steel sheet, the difference in annealing temperature between the steel sheets increases when producing several types of steel sheets, thereby reducing productivity.
- the cold-rolled steel sheet is annealed at a temperature of 400.0 to 580.0 °C.
- the annealing temperature is lower than the normal recrystallization annealing temperature, and corresponds to the recovery annealing temperature for removing some of the dislocations accumulated in the steel during cold rolling. This is to improve elongation by removing a significant amount of dislocations accumulated during cold rolling through recovery.
- annealing at less than 400°C dislocations generated during cold rolling do not sufficiently disappear, resulting in poor ductility, and when it exceeds 580°C, recrystallization occurs and strength is greatly reduced. More specifically, it may be annealed at a temperature of 430.0 to 575.0 °C.
- the plated steel sheet may be manufactured by hot-dip plating or electroplating on one or both surfaces of the cold-rolled steel sheet to form a plating layer.
- the slab was reheated to 1230° C. and hot-rolled at 900° C. or higher, and winding, cold rolling, and annealing were performed according to the manufacturing conditions in Table 2 below to obtain an annealed steel sheet having a thickness of 1 mm.
- the annealing was carried out in a coil state through the continuous annealing method to raise the temperature to the corresponding temperature, hold it for 1 minute, and then cool it to room temperature.
- Comparative Steel 3 cracks occurred during hot rolling, so cold rolling and annealing were not performed, thereby omitting subsequent physical property measurement.
- the strengthening index, grain aspect ratio, dislocation density, recrystallization area ratio, and average grain size were measured and calculated as shown in Table 3 below.
- the reinforcing index was defined as in Relation 1 below, and was calculated from the components of the steel.
- the average grain size was measured from the observation of the optical microstructure, and the area of the recrystallized grains was measured to measure the recrystallized area ratio and presented together.
- the grain aspect ratio defined by the following Relation 2 was statistically calculated from observation of the optical microstructure, and the dislocation density was measured and expressed through XRD (X-ray diffraction).
- Grain aspect ratio (average grain diameter in rolling direction) / (average grain diameter in thickness direction)
- Developed steels 1 to 14 in Table 4 suitably satisfy the reinforcing index, grain aspect ratio, dislocation density, recrystallization area ratio, and grain size, and have a yield strength of 650 MPa or less and an elongation of 7% or more, suitable for mechanical processing into structural materials. level.
- all of the developed steels have a yield strength of 180 MPa or more and an elongation of 25% or more after the above-described mechanical and thermal processing. An elongation of less than 25% is unsuitable for complex molding, and a yield strength of less than 180 MPa is unsuitable for maintaining shape as a structural material.
- Comparative Steel 1 has a C content of less than 0.012 wt% and a reinforcing index of less than 1.0. Accordingly, the yield strength after processing is less than 180 MPa, which is not suitable. Conversely, Comparative Steel 2 had a C content of more than 0.060% by weight and a reinforcing index of 3.0. Accordingly, the yield strength of the annealed steel sheet exceeds 650 MPa and the elongation is less than 7%, making it difficult to form as described above.
- Comparative Steel 3 had a Mn content of less than 0.1 wt%, and cracks occurred in the hot-rolled steel sheet due to brittleness caused by S during hot rolling. When S in the steel combines with Mn and sufficiently precipitates in the form of MnS, brittleness is suppressed, but when Mn is insufficient, brittleness appears strongly. Comparative Steel 4 had Mn exceeding 0.4% by weight, reinforcing index exceeding 3.0, yield strength exceeding 650 MPa, and elongation was as low as less than 7%.
- Comparative Steel 5 had an N content of more than 0.006% by weight, and thus had good physical properties before processing and excellent yield strength of 180 MPa or more after processing.
- Comparative steels 6 and 7 have a reinforcing index of less than 1.0 and a yield strength of less than 180 MPa after processing, making it difficult to maintain the shape. Conversely, it can be seen that Comparative Steels 8 to 9 have a reinforcing index exceeding 3.0, so that the strength of the annealed steel sheet exceeds 650M and the elongation is low as less than 7%.
- Comparative Steel 10 had a coiling temperature of less than 600 °C, and as the coiling temperature was lowered, the grain size was formed as small as 7.8 ⁇ m. In this case, the crystal grains generated during the recrystallization process during thermal processing after mechanical processing are also formed small, so that the strength is high enough, but the elongation is low at 25% or less, which is not suitable.
- Comparative Steel 11 has a very large grain size of 13.7 ⁇ m as the coiling temperature exceeds 700° C. In the case of large grains, recrystallization does not occur easily even when thermally processed. Accordingly, the mechanically processed stress is not sufficiently relieved, so the strength is very high, but the elongation is greatly lowered to less than 20%, making it difficult to use.
- Comparative Steel 12 has a low cold reduction ratio of less than 20% and a low grain aspect ratio of less than 1.25.
- the initial strength is low and the elongation is high, which is advantageous for mechanical processing.
- recrystallization does not occur sufficiently during thermal processing, so the elongation after processing is low to 15% or less, making it unsuitable for use.
- the grain aspect ratio exceeds 2.5 and the dislocation density exceeds 2.5X10 15 /m 2 .
- the recrystallization driving force is high, recrystallization occurs partially during annealing of the cold-rolled steel sheet.
- the recrystallization area ratio exceeds 3%.
- the recrystallization driving force for recrystallization to occur even after mechanical processing and thermal processing is relatively low in the portion where the recrystallized grains are formed after annealing of the cold-rolled steel sheet because most of the stress is relieved. Due to these reasons, it can be seen that the elongation is lowered to less than 20% as recrystallization does not occur sufficiently after thermal processing.
- Comparative Steel 14 the annealing temperature of the cold-rolled steel sheet is lower than 400°C, so recovery does not occur sufficiently, and the grain size is small. Accordingly, the elongation after annealing is lowered to less than 7%, and the workability is deteriorated. Conversely, Comparative Steel 15 has a recrystallization area ratio exceeding 3% due to active partial recrystallization due to an annealing temperature exceeding 580°C. Accordingly, it can be seen that the recrystallization after thermal processing does not occur because the recrystallization driving force is not sufficient even after mechanical processing in the portion where recrystallization has occurred, as described above, so that the elongation is as low as 20% or less.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
성분 (중량%) | |||||||
C | Si | Mn | Al | P | S | N | |
비교강1 | 0.0101 | 0.014 | 0.165 | 0.035 | 0.0060 | 0.0077 | 0.0023 |
개발강1 | 0.0131 | 0.011 | 0.200 | 0.044 | 0.0078 | 0.0074 | 0.0023 |
개발강2 | 0.0250 | 0.011 | 0.193 | 0.042 | 0.0063 | 0.0077 | 0.0023 |
개발강3 | 0.0420 | 0.006 | 0.212 | 0.047 | 0.0079 | 0.0064 | 0.0034 |
개발강4 | 0.0520 | 0.010 | 0.211 | 0.050 | 0.0066 | 0.0074 | 0.0033 |
비교강2 | 0.0620 | 0.008 | 0.206 | 0.031 | 0.0061 | 0.0077 | 0.0036 |
비교강3 | 0.0156 | 0.013 | 0.050 | 0.044 | 0.0072 | 0.0070 | 0.0034 |
개발강5 | 0.0404 | 0.011 | 0.142 | 0.043 | 0.0066 | 0.0069 | 0.0032 |
개발강6 | 0.0371 | 0.010 | 0.256 | 0.029 | 0.0079 | 0.0066 | 0.0028 |
개발강7 | 0.0404 | 0.009 | 0.389 | 0.041 | 0.0063 | 0.0070 | 0.0026 |
비교강4 | 0.0450 | 0.009 | 0.450 | 0.035 | 0.0079 | 0.0071 | 0.0029 |
개발강8 | 0.0376 | 0.008 | 0.208 | 0.031 | 0.0078 | 0.0072 | 0.0051 |
비교강5 | 0.0385 | 0.015 | 0.204 | 0.040 | 0.0069 | 0.0064 | 0.0068 |
비교강6 | 0.0131 | 0.012 | 0.120 | 0.024 | 0.0074 | 0.0070 | 0.0036 |
비교강7 | 0.0115 | 0.009 | 0.126 | 0.047 | 0.0075 | 0.0065 | 0.0025 |
비교강8 | 0.0520 | 0.013 | 0.250 | 0.022 | 0.0075 | 0.0061 | 0.0023 |
비교강9 | 0.0480 | 0.010 | 0.380 | 0.030 | 0.0072 | 0.0075 | 0.0028 |
비교강10 | 0.0385 | 0.015 | 0.199 | 0.027 | 0.0069 | 0.0066 | 0.0022 |
개발강9 | 0.0407 | 0.006 | 0.219 | 0.027 | 0.0079 | 0.0078 | 0.0039 |
개발강10 | 0.0439 | 0.014 | 0.207 | 0.027 | 0.0062 | 0.0072 | 0.0039 |
비교강11 | 0.0448 | 0.011 | 0.200 | 0.024 | 0.0062 | 0.0066 | 0.0037 |
비교강12 | 0.0424 | 0.014 | 0.203 | 0.022 | 0.0073 | 0.0060 | 0.0030 |
개발강11 | 0.0369 | 0.011 | 0.220 | 0.048 | 0.0061 | 0.0066 | 0.0031 |
개발강12 | 0.0370 | 0.014 | 0.201 | 0.022 | 0.0078 | 0.0067 | 0.0031 |
비교강13 | 0.0418 | 0.014 | 0.205 | 0.039 | 0.0080 | 0.0079 | 0.0024 |
비교강14 | 0.0361 | 0.011 | 0.211 | 0.039 | 0.0079 | 0.0065 | 0.0034 |
개발강13 | 0.0395 | 0.007 | 0.188 | 0.048 | 0.0067 | 0.0080 | 0.0023 |
개발강14 | 0.0449 | 0.012 | 0.186 | 0.044 | 0.0074 | 0.0078 | 0.0035 |
비교강15 | 0.0442 | 0.012 | 0.207 | 0.035 | 0.0071 | 0.0070 | 0.0020 |
구분 | 권취온도 (℃) | 냉간 압하율 (%) | 소둔 온도 (℃) |
비교강1 | 654.3 | 40.6 | 543.5 |
개발강1 | 650.9 | 40.1 | 542.8 |
개발강2 | 652.9 | 40.3 | 536.1 |
개발강3 | 652.9 | 40.9 | 545.0 |
개발강4 | 653.1 | 40.7 | 533.2 |
비교강2 | 649.3 | 40.6 | 531.0 |
비교강3 | 651.1 | - | - |
개발강5 | 646.3 | 40.8 | 543.1 |
개발강6 | 652.7 | 40.2 | 546.4 |
개발강7 | 648.4 | 40.5 | 540.3 |
비교강4 | 647.8 | 40.0 | 543.2 |
개발강8 | 650.5 | 39.3 | 540.9 |
비교강5 | 647.8 | 39.1 | 549.6 |
비교강6 | 651.6 | 40.1 | 546.5 |
비교강7 | 654.9 | 39.9 | 545.3 |
비교강8 | 649.9 | 39.5 | 536.7 |
비교강9 | 651.3 | 38.5 | 539.6 |
비교강10 | 580.2 | 40.0 | 545.0 |
개발강9 | 611.5 | 40.2 | 546.6 |
개발강10 | 689.8 | 39.9 | 530.6 |
비교강11 | 720.4 | 40.3 | 537.6 |
비교강12 | 653.6 | 16.8 | 535.3 |
개발강11 | 650.7 | 24.4 | 530.8 |
개발강12 | 645.0 | 55.4 | 530.8 |
비교강13 | 651.3 | 60.5 | 535.3 |
비교강14 | 650.0 | 40.8 | 385.1 |
개발강13 | 654.4 | 40.4 | 431.5 |
개발강14 | 650.9 | 39.6 | 572.5 |
비교강15 | 652.4 | 39.4 | 590.8 |
구분 | 강화지수 | 결정립 형상비 | 전위밀도 | 재결정 면적비 | 평균 결정립경 |
(관계식 1) | (관계식 2) | (X1015/m2) | (면적%) | (μm) | |
비교강1 | 0.805 | 1.60 | 1.17 | 0 | 11.8 |
개발강1 | 1.018 | 1.76 | 1.33 | 0 | 11.3 |
개발강2 | 1.601 | 1.60 | 1.20 | 0 | 10.2 |
개발강3 | 2.483 | 1.68 | 1.43 | 0 | 10.0 |
개발강4 | 2.982 | 1.72 | 1.45 | 0 | 9.1 |
비교강2 | 3.472 | 1.62 | 1.47 | 0 | 8.8 |
비교강3 | - | - | - | - | - |
개발강5 | 2.277 | 1.71 | 1.32 | 0 | 9.1 |
개발강6 | 2.317 | 1.74 | 1.32 | 0 | 8.5 |
개발강7 | 2.724 | 1.62 | 1.49 | 0 | 8.6 |
비교강4 | 3.067 | 1.65 | 1.40 | 0 | 8.1 |
개발강8 | 2.257 | 1.63 | 1.13 | 0 | 10.3 |
비교강5 | 2.293 | 1.76 | 1.37 | 0 | 9.2 |
비교강6 | 0.873 | 1.57 | 1.43 | 0 | 11.2 |
비교강7 | 0.803 | 1.68 | 1.31 | 0 | 11.4 |
비교강8 | 3.053 | 1.72 | 1.29 | 0 | 8.3 |
비교강9 | 3.089 | 1.68 | 1.42 | 0 | 8.4 |
비교강10 | 2.287 | 1.73 | 1.13 | 0 | 7.8 |
개발강9 | 2.431 | 1.72 | 1.26 | 0 | 8.3 |
개발강10 | 2.571 | 1.69 | 1.32 | 0 | 11.5 |
비교강11 | 2.605 | 1.58 | 1.23 | 0 | 13.7 |
비교강12 | 2.485 | 1.21 | 0.65 | 0 | 10.6 |
개발강11 | 2.242 | 1.32 | 1.18 | 0 | 9.0 |
개발강12 | 2.213 | 2.31 | 1.11 | 2.5 | 8.5 |
비교강13 | 2.462 | 2.58 | 2.80 | 3.6 | 8.1 |
비교강14 | 2.186 | 1.68 | 1.15 | 0 | 7.8 |
개발강13 | 2.317 | 1.64 | 1.37 | 0 | 10.2 |
개발강14 | 2.580 | 1.59 | 1.17 | 1.6 | 10.3 |
비교강15 | 2.586 | 1.52 | 1.39 | 6.8 | 10.6 |
구분 | 소둔 강판의 기계적 물성 | 가공 후 기계적 물성 | ||
항복강도(MPa) | 연신율(%) | 항복강도(MPa) | 연신율(%) | |
비교강1 | 441.5 | 12.8 | 174.1 | 33.6 |
개발강1 | 466.8 | 10.5 | 186.5 | 31.5 |
개발강2 | 492.2 | 8.8 | 216.5 | 28.2 |
개발강3 | 562.7 | 8.5 | 223.3 | 28.3 |
개발강4 | 640.5 | 7.6 | 232.2 | 26.1 |
비교강2 | 672.5 | 6.5 | - | - |
비교강3 | - | - | - | - |
개발강5 | 520.5 | 8.9 | 186.9 | 29.0 |
개발강6 | 560.5 | 8.6 | 218.0 | 27.3 |
개발강7 | 632.0 | 7.5 | 227.9 | 28.6 |
비교강4 | 665.3 | 6.4 | - | - |
개발강8 | 538.9 | 8.2 | 235.5 | 26.5 |
비교강5 | 534.4 | 9.4 | 272.1 | 22.1 |
비교강6 | 431.3 | 10.9 | 168.5 | 34.5 |
비교강7 | 435.5 | 11 | 172.0 | 33.6 |
비교강8 | 670.5 | 6.8 | - | - |
비교강9 | 668.8 | 6.5 | - | - |
비교강10 | 638.5 | 7.3 | 265.5 | 24.8 |
개발강9 | 625.0 | 7.8 | 240.0 | 26.8 |
개발강10 | 505.5 | 9.5 | 218.2 | 27.5 |
비교강11 | 490.5 | 11.5 | 385.6 | 16.5 |
비교강12 | 449.6 | 8.4 | 480.6 | 13.5 |
개발강11 | 495.5 | 8.3 | 210.3 | 29.6 |
개발강12 | 521.1 | 8.4 | 232.5 | 25.8 |
비교강13 | 485.5 | 13.5 | 285.5 | 19.6 |
비교강14 | 600.1 | 6.5 | - | - |
개발강13 | 535.1 | 7.6 | 219.2 | 26.9 |
개발강14 | 530.5 | 11.5 | 199.9 | 30.0 |
비교강15 | 380.6 | 16.8 | 371.5 | 18.9 |
Claims (9)
- 중량%로 C: 0.012 내지 0.060%, Si: 0.03% 이하(0%를 제외함), Mn: 0.1 내지 0.4%, Al: 0.015 내지 0.050%, P: 0.015% 이하(0%를 제외함), S: 0.015% 이하(0%를 제외함) 및 N: 0.006% 이하(0%를 제외함)를 포함하고, 잔부는 Fe 및 기타 불가피한 불순물을 포함하고,하기 식 1로 정의되는 강화지수가 1.0 내지 3.0이고,하기 식 2로 정의되는 결정립 형상비가 1.25 내지 2.50이고,재결정 면적비가 3% 이하이고,평균 결정립경이 8 내지 12㎛인 가공성이 우수한 냉연강판.[식 1]강화지수 = [([C]/12.011)× 6 + ([Mn]/54.938)] × 100(식 1에서 [C], [Mn]은 각 성분함량의 중량%를 의미한다.)[식 2]결정립 형상비 = (압연방향 평균 결정립 직경) / (두께방향 평균 결정립 직경)
- 제1항에 있어서,Cu: 0.003% 이하, Nb: 0.01 중량% 이하, Sb: 0.03 중량% 이하, Sn: 0.03 중량% 이하, Ni: 0.03 중량% 이하, Cr: 0.03 중량% 이하 및 Mo: 0.03 중량% 이하 중 1종 이상을 더 포함하는 가공성이 우수한 냉연강판.
- 제1항에 있어서,전위밀도가 2.5X1015/m2이하인 가공성이 우수한 냉연강판.
- 제1항에 기재된 냉연강판 및 상기 냉연강판의 일면 또는 양면에 위치하는 도금층을 포함하는 도금 강판.
- 중량%로 C: 0.012 내지 0.060%, Si: 0.03% 이하(0%를 제외함), Mn: 0.1 내지 0.4%, Al: 0.015 내지 0.050%, P: 0.015% 이하(0%를 제외함), S: 0.015% 이하(0%를 제외함) 및 N: 0.006% 이하(0%를 제외함)를 포함하고, 잔부는 Fe 및 기타 불가피한 불순물을 포함하고, 하기 식 1로 정의되는 강화지수가 1.0 내지 3.0인 슬라브를 열간압연하여 열연강판을 제조하는 단계;슬라브를 Ar3 이상에서 열간 마무리 압연하여 열연강판을 제조하는 단계;상기 열연강판을 600 내지 700℃에서 권취하는 단계;권취된 열연강판을 20 내지 60% 압하율로 냉간압연하여 냉연강판을 제조하는 단계 및상기 냉연강판을 400 내지 580℃의 온도에서 소둔하는 단계를 포함하는 가공성이 우수한 냉연강판의 제조방법.[식 1]강화지수 = [([C]/12.011)× 6 + ([Mn]/54.938)] × 100(식 1에서 [C], [Mn]은 각 성분함량의 중량%를 의미한다.)
- 제5항에 있어서,상기 열연강판을 제조하는 단계 이전에 슬라브를 1150℃ 이상에서 가열하는 단계를 더 포함하는 가공성이 우수한 냉연강판의 제조방법.
- 제5항에 있어서,상기 열연강판을 제조하는 단계에서 Ar3 이상에서 열간 마무리 압연하는 가공성이 우수한 냉연강판의 제조방법.
- 제5항에 있어서,상기 소둔하는 단계 이후, 소둔판을 0.4 내지 2.0%의 압하율로 조질압연하는 단계를 더 포함하는 가공성이 우수한 냉연강판의 제조방법.
- 제5항에 기재된 방법으로 냉연강판을 제조하는 단계; 및상기 냉연강판의 일면 또는 양면에 용융도금 내지 전기도금하여 도금층을 형성하는 단계를 포함하는 도금 강판의 제조 방법.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2023537690A JP2024500859A (ja) | 2020-12-21 | 2021-12-15 | 加工性に優れた冷間圧延鋼板及びその製造方法 |
EP21911376.8A EP4265753A4 (en) | 2020-12-21 | 2021-12-15 | COLD-ROLLED STEEL SHEET HAVING EXCELLENT PROCESSABILITY AND METHOD FOR MANUFACTURING SAME |
CN202180086018.6A CN116601314A (zh) | 2020-12-21 | 2021-12-15 | 加工性优异的冷轧钢板及其制造方法 |
US18/268,388 US20240018620A1 (en) | 2020-12-21 | 2021-12-15 | Cold-rolled steel sheet having excellent processability and manufacturing method thereof |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR10-2020-0179383 | 2020-12-21 | ||
KR1020200179383A KR102438481B1 (ko) | 2020-12-21 | 2020-12-21 | 가공성이 우수한 냉연강판 및 그 제조방법 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2022139309A1 true WO2022139309A1 (ko) | 2022-06-30 |
Family
ID=82159598
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/KR2021/019101 WO2022139309A1 (ko) | 2020-12-21 | 2021-12-15 | 가공성이 우수한 냉연강판 및 그 제조방법 |
Country Status (6)
Country | Link |
---|---|
US (1) | US20240018620A1 (ko) |
EP (1) | EP4265753A4 (ko) |
JP (1) | JP2024500859A (ko) |
KR (1) | KR102438481B1 (ko) |
CN (1) | CN116601314A (ko) |
WO (1) | WO2022139309A1 (ko) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20040027981A (ko) * | 2001-08-24 | 2004-04-01 | 신닛뽄세이테쯔 카부시키카이샤 | 가공성이 우수한 강판 및 제조 방법 |
KR20100106843A (ko) * | 2009-03-24 | 2010-10-04 | 주식회사 포스코 | 소부경화성이 우수한 질화물계 고강도 강판과 그 제조방법 |
KR20110105403A (ko) * | 2009-03-05 | 2011-09-26 | 제이에프이 스틸 가부시키가이샤 | 굽힘 가공성이 우수한 냉연 강판, 그 제조 방법 및 그것을 사용한 부재 |
US20140102604A1 (en) * | 2012-10-11 | 2014-04-17 | Thyssenkrupp Steel Usa, Llc | Cold rolled recovery annealed mild steel and process for manufacture thereof |
JP2017057462A (ja) * | 2015-09-16 | 2017-03-23 | 新日鐵住金株式会社 | 無方向性電磁鋼板およびその製造方法 |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101353634B1 (ko) * | 2011-11-18 | 2014-01-21 | 주식회사 포스코 | 용접성과 강도가 우수한 저합금 냉연강판 및 그 제조방법 |
KR101585739B1 (ko) * | 2013-12-25 | 2016-01-14 | 주식회사 포스코 | 충격특성이 우수한 고항복비형 냉연강판 및 그 제조방법 |
-
2020
- 2020-12-21 KR KR1020200179383A patent/KR102438481B1/ko active IP Right Grant
-
2021
- 2021-12-15 JP JP2023537690A patent/JP2024500859A/ja active Pending
- 2021-12-15 CN CN202180086018.6A patent/CN116601314A/zh active Pending
- 2021-12-15 US US18/268,388 patent/US20240018620A1/en active Pending
- 2021-12-15 EP EP21911376.8A patent/EP4265753A4/en active Pending
- 2021-12-15 WO PCT/KR2021/019101 patent/WO2022139309A1/ko active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20040027981A (ko) * | 2001-08-24 | 2004-04-01 | 신닛뽄세이테쯔 카부시키카이샤 | 가공성이 우수한 강판 및 제조 방법 |
KR20110105403A (ko) * | 2009-03-05 | 2011-09-26 | 제이에프이 스틸 가부시키가이샤 | 굽힘 가공성이 우수한 냉연 강판, 그 제조 방법 및 그것을 사용한 부재 |
KR20100106843A (ko) * | 2009-03-24 | 2010-10-04 | 주식회사 포스코 | 소부경화성이 우수한 질화물계 고강도 강판과 그 제조방법 |
US20140102604A1 (en) * | 2012-10-11 | 2014-04-17 | Thyssenkrupp Steel Usa, Llc | Cold rolled recovery annealed mild steel and process for manufacture thereof |
JP2017057462A (ja) * | 2015-09-16 | 2017-03-23 | 新日鐵住金株式会社 | 無方向性電磁鋼板およびその製造方法 |
Non-Patent Citations (1)
Title |
---|
See also references of EP4265753A4 * |
Also Published As
Publication number | Publication date |
---|---|
CN116601314A (zh) | 2023-08-15 |
EP4265753A1 (en) | 2023-10-25 |
KR20220089735A (ko) | 2022-06-29 |
US20240018620A1 (en) | 2024-01-18 |
KR102438481B1 (ko) | 2022-09-01 |
EP4265753A4 (en) | 2024-05-15 |
JP2024500859A (ja) | 2024-01-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2018117646A1 (ko) | 극저온 충격인성이 우수한 후강판 및 이의 제조방법 | |
WO2020060051A1 (ko) | 충격 인성이 우수한 페라이트계 스테인리스 열연 무소둔 강판 및 그 제조방법 | |
WO2017222159A1 (ko) | 가공성이 우수한 고강도 냉연강판 및 그 제조 방법 | |
WO2013154254A1 (ko) | 재질 균일성이 우수한 고탄소 열연강판 및 이의 제조방법 | |
WO2020111857A1 (ko) | 크리프 강도가 우수한 크롬-몰리브덴 강판 및 그 제조방법 | |
WO2010074458A2 (ko) | 딥드로잉성이 우수하고 고항복비를 갖는 고강도 냉연강판, 이를 이용한 용융아연도금강판, 합금화 용융아연도금강판 및 이들의 제조방법 | |
WO2021125724A2 (ko) | 내열성과 성형성이 우수한 냉연강판 및 그 제조방법 | |
WO2022139309A1 (ko) | 가공성이 우수한 냉연강판 및 그 제조방법 | |
WO2022139314A1 (ko) | 무방향성 전기강판 및 그 제조방법 | |
WO2023075287A1 (ko) | 페라이트계 스테인리스강 및 그 제조방법 | |
WO2019039774A1 (ko) | 저온 충격인성이 개선된 페라이트계 스테인리스강 및 이의 제조 방법 | |
WO2023113558A1 (ko) | 프레스 성형성이 우수한 냉연강판, 아연도금강판, 및 이들의 제조 방법 | |
WO2018110866A1 (ko) | 충격 인성이 개선된 페라이트계 스테인리스강 및 이의 제조 방법 | |
WO2022131802A1 (ko) | 재질 균일성이 우수한 고강도 냉연, 도금 강판 및 이들의 제조 방법 | |
WO2020130257A1 (ko) | 연성 및 가공성이 우수한 고강도 강판 및 그 제조방법 | |
WO2024071522A1 (ko) | 초고강도 강판 및 그 제조방법 | |
WO2023234503A1 (ko) | 초고강도 냉연강판 및 그 제조방법 | |
WO2023048495A1 (ko) | 구멍확장성이 우수한 초고강도 냉연강판 및 그 제조방법 | |
WO2024072023A1 (ko) | 냉연강판 및 그 제조방법 | |
WO2021025248A1 (ko) | 고온 내크립 특성이 향상된 페라이트계 스테인리스강 및 그 제조 방법 | |
WO2023234509A1 (ko) | 핫 스탬핑 부품 및 이의 제조 방법 | |
WO2023234508A1 (ko) | 핫 스탬핑 부품 및 이의 제조 방법 | |
WO2024143832A1 (ko) | 고강도 및 고성형성 강판 및 그 제조방법 | |
WO2024058312A1 (ko) | 초고강도 냉연 강판 및 그 제조방법 | |
WO2022119134A1 (ko) | 입계침식이 개선된 페라이트계 스테인리스강 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: 21911376 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 202180086018.6 Country of ref document: CN Ref document number: 18268388 Country of ref document: US Ref document number: 2023537690 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2021911376 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2021911376 Country of ref document: EP Effective date: 20230721 |