WO2013103117A1 - 合金化溶融亜鉛めっき鋼板 - Google Patents
合金化溶融亜鉛めっき鋼板 Download PDFInfo
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- WO2013103117A1 WO2013103117A1 PCT/JP2012/083671 JP2012083671W WO2013103117A1 WO 2013103117 A1 WO2013103117 A1 WO 2013103117A1 JP 2012083671 W JP2012083671 W JP 2012083671W WO 2013103117 A1 WO2013103117 A1 WO 2013103117A1
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- 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
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- 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
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- 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
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- 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
- C21D8/0278—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a particular surface treatment
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- 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
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C18/00—Alloys based on zinc
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
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- 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
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
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- 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
- C23C2/26—After-treatment
- C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
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- 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
- C21D2211/004—Dispersions; Precipitations
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12771—Transition metal-base component
- Y10T428/12785—Group IIB metal-base component
- Y10T428/12792—Zn-base component
- Y10T428/12799—Next to Fe-base component [e.g., galvanized]
Definitions
- the present invention relates to an alloyed hot-dip galvanized steel sheet that realizes chipping resistance and post-coating adhesion suitable for use as a steel sheet for automobiles.
- Hot rolled steel sheets with a tensile strength (TS) of 440 MPa or less have been used for members such as automobile and truck frames and undercarriages. Recently, for the purpose of improving the impact resistance of automobiles and preserving the global environment, they are used for automobiles. High-strength hot-rolled steel sheets are being used as steel sheets are becoming stronger and thinner and lighter. For this reason, there is a demand for a surface-treated steel sheet that has high strength and excellent workability, and has been given rust prevention from the viewpoint of securing the rust prevention power of the vehicle body due to the thinning of the steel sheet, and in particular, corrosion resistance and weldability. There is a demand for an alloyed hot-dip galvanized steel sheet that is superior to the above.
- Patent Document 1 in mass%, C: 0.02 to 0.06%, Si ⁇ 0.3%, Mn: 0.5 to 2.0%, P ⁇ 0.06%, S ⁇ 0 0.005%, Al ⁇ 0.06%, N ⁇ 0.006%, Mo: 0.05 to 0.5%, Ti: 0.03 to 0.14%, the balance being substantially made of Fe By melting steel and performing hot rolling under conditions of finish rolling finish temperature of 880 ° C. or higher and coiling temperature of 570 ° C.
- Ti and Mo having substantially a ferrite single-phase structure and an average particle size of less than 10 nm are obtained.
- Patent Document 2 by mass, C: 0.01 to 0.1%, Si ⁇ 0.3%, Mn: 0.2 to 2.0%, P ⁇ 0.04%, S ⁇ 0 0.02%, Al ⁇ 0.1%, N ⁇ 0.006%, Ti: 0.03 to 0.2%, and one or more of Mo ⁇ 0.5% and W ⁇ 1.0% Steel, the balance being Fe and inevitable impurities are melted, hot-rolled in the austenite single-phase region, wound at 550 ° C. or more, and after producing a single-phase ferrite hot-rolled steel sheet, the scale is further removed.
- the hot dip galvanizing As it is, it is 4.8C + 4.2Si + 0.4Mn + 2Ti ⁇ 2.5 in mass%, and the structure is ferrite with an area ratio of 98% or more, and in atomic ratio, (Mo + W) / In the range satisfying (Ti + Mo + W) ⁇ 0.2, at least one of Ti, Mo and W Precipitates of less than 10nm, including a is characterized by the presence in the dispersion method of producing a hot-dip galvanized high-strength hot-rolled steel sheet is disclosed.
- Patent Document 3 by performing mechanical elongation control or pickling treatment on the hot dip galvanized steel sheet after alloying treatment.
- An alloyed hot-dip galvanized steel sheet having 10 or more cracks per mm on the surface of the hot-dip plating film and excellent in powdering resistance and low-temperature chipping resistance is disclosed.
- Patent Document 4 discloses a method for improving plating adhesion by providing an alloyed hot-dip galvanized film on a cold-rolled steel sheet having predetermined irregularities.
- JP 2002-322543 A JP 2003-321736 A Japanese Patent Laid-Open No. 11-200000 JP-A-4-280953
- Patent Documents 1 to 4 described above have the following problems.
- Patent Documents 1 and 2 in order to precipitate fine carbides including Ti and Mo in ferrite, it is necessary to perform winding at a winding temperature of 550 ° C. or higher (hereinafter also referred to as CT) after finishing rolling. is there.
- CT winding temperature
- an easily oxidizable element When a winding process is performed under such high CT conditions on a base steel sheet containing an element that is easier to oxidize than Fe, such as Si and Mn (hereinafter referred to as an easily oxidizable element), the base steel sheet surface layer portion An internal oxide containing an easily oxidizable element is generated.
- the Zn—Fe alloying reaction is excessively promoted, resulting in a problem that the plating adhesion deteriorates.
- the phenomenon that the coating or plating film peels off due to the impact of chipping caused by pebbles during running may occur, but excessive Zn-Fe alloying reaction also causes deterioration of the chipping resistance of the plating film.
- the surface of the surface is larger than that of cold-rolled steel sheet, so that the zinc phosphate crystal film grows thick in the chemical conversion treatment process that is carried out before coating film formation. There is a problem that the adhesion at the coating film-plating layer interface after coating is poor.
- Patent Document 3 Although the plating adhesion and chipping resistance are improved, cracks are generated in the hot-dipped film at high density, so there is a concern about deterioration of corrosion resistance. Furthermore, an alkali and pickling treatment facility is required as a post-treatment step for generating cracks on the surface of the hot-dip plating film, resulting in a problem of facility cost. Furthermore, in Patent Document 4, when a hot-rolled steel sheet is used as the base material steel sheet, it is difficult to control the surface roughness because the surface unevenness is large. Furthermore, when the surface roughness is increased, the zinc phosphate crystal film is likely to grow thick, and sufficient adhesion with the coating film cannot be ensured.
- the present invention has been made in view of the above circumstances, and an object thereof is to provide an galvannealed steel sheet excellent in chipping resistance and adhesion after coating while ensuring corrosion resistance.
- the present inventors are selected from the group consisting of Ti, Nb, V, Mo, and W in the galvannealed layer of the galvannealed steel sheet. It has been found that by dispersing a precipitate containing one or more kinds, chipping resistance and adhesion after coating are improved while ensuring corrosion resistance. More specifically, the cause of the improvement in chipping resistance is that when the alloyed hot dip galvanized layer receives an impact due to chipping and cracks occur at the plating-steel base metal interface, It is presumed that the predetermined precipitate has a pinning effect at the crack generation portion, and the propagation of the crack is stopped by this pinning effect and does not lead to large peeling.
- the zinc phosphate crystal in the zinc phosphate crystal film which is the underlayer provided in the film, is formed to be a fine crystal film without excessively thick formation, resulting in improved adhesion after coating.
- a predetermined precipitate existing on the surface of the alloyed hot dip galvanized layer, particularly on the surface side of the alloyed hot dip galvanized layer (opposite side of the base steel plate side) becomes a nucleation site of zinc phosphate crystals.
- the alloyed hot-dip galvanized steel sheet of the present invention contains a precipitate containing one or more selected from the group consisting of Ti, Nb, V, Mo, and W in the alloyed hot-dip galvanized layer. Even when a high-strength hot-rolled steel sheet is used as the base material, it has excellent corrosion resistance, chipping resistance, and adhesion after coating, and is extremely effective for applications such as automobile frames and underbody parts.
- the alloyed hot-dip galvanized steel sheet of the present invention has a base steel sheet having a predetermined component composition, and an alloyed hot-dip galvanized layer containing predetermined precipitates provided on the base steel sheet.
- the base steel sheet and the galvannealed layer will be described in detail.
- the "%" display regarding the component mentioned later shall mean the mass% unless there is particular notice.
- the base steel plate in the galvannealed steel plate is C: 0.02% to 0.30%, Si: 0.01% to 2.50%, Mn: 0.1% to 3.0%
- P 0.003% or more and 0.080% or less
- S 0.01% or less
- Al 0.001% or more and 0.200% or less
- Ti 0.03% or more and 0.000% or less.
- Nb 0.001% or more and 0.200% or less
- V 0.001% or more and 0.500% or less
- Mo 0.01% or more and 0.50% or less
- W 0.001% It contains one or more of 0.200% or less and the remainder has a component composition consisting of Fe and inevitable impurities.
- the reasons for limiting the component composition of the base steel sheet will be described.
- C (C: 0.02% to 0.30%) C is an element necessary for precipitating carbides in the base material steel plate and increasing the strength of the base material steel plate, and must be contained in an amount of 0.02% or more. On the other hand, if the C content exceeds 0.30%, weldability deteriorates. Therefore, the C content is 0.02% or more and 0.30% or less.
- Si 0.01% to 2.50%
- Si is effective as a solid solution strengthening element and is preferably contained in an amount of 0.01% or more in order to exhibit a strengthening effect.
- Si exceeds 2.50%
- Si oxide concentrates on the surface of the base steel plate during the CGL (hot dip galvanized steel plate manufacturing equipment) annealing process, causing non-plating defects and poor plating adhesion.
- the Si content is 0.01% or more and 2.50% or less.
- Mn 0.1% to 3.0%
- Mn is added to increase the strength of the base steel plate, and is preferably contained in an amount of 0.1% or more, more preferably 0.6% or more in order to exhibit a strengthening effect.
- Mn exceeds 3.0%, Mn oxide is concentrated on the surface of the base steel sheet during the CGL annealing process, which causes non-plating defects and deterioration of plating adhesion. Therefore, the Mn content is 0.1% or more and 3.0% or less.
- P 0.003% to 0.080%
- P is one of the elements inevitably contained, and is effective for strengthening the steel sheet. The effect is obtained at 0.003% or more, and the cost is required to make the content less than 0.003%. There is concern about the increase.
- P exceeds 0.080% weldability deteriorates and surface quality deteriorates.
- the alloying treatment temperature is not increased, the desired alloying degree cannot be obtained unless the alloying treatment temperature is increased.
- the alloying treatment temperature is increased, the ductility of the base steel sheet is deteriorated and at the same time the alloyed hot-dip galvanized layer. The adhesiveness of the deteriorates. Therefore, the P content is 0.003% or more and 0.08% or less.
- Al 0.001% or more and 0.200% or less
- Al is added for the purpose of deoxidizing molten steel, but if the content is less than 0.001%, the purpose is not achieved. On the other hand, if the content exceeds 0.200%, a large amount of inclusions are generated, which causes wrinkling of the steel sheet. Therefore, the Al content is 0.001% or more and 0.200% or less.
- Ti, Nb, V, Mo, and W are elements necessary for depositing precipitates (particularly carbides) in the base steel sheet, and one or more selected from the group consisting of these elements. Added. Usually, these elements are often contained in the form of precipitates containing these elements in the base steel sheet. Among these elements, Ti is particularly an element that has a high precipitation strengthening ability and is effective from the viewpoint of cost.
- the addition amount is less than 0.03%, the amount of precipitates in the base steel plate necessary for including precipitates (particularly carbides) in the galvannealed layer is insufficient, and 0.40% If the value is exceeded, the effect is saturated and the cost is increased. Therefore, the Ti content is 0.03% or more and 0.40% or less.
- the Nb content is 0.001 to 0.200%
- the V content is 0.001 to 0.500%
- the Mo amount is 0.01 to 0.50%
- the W amount is 0.001 to 0.200%.
- B is an element that is optionally added to improve the hardenability, and is preferably 0% or more and 0.005% or less, more preferably 0.0005% or more and 0 or more, in that the plating adhesion is more excellent together with the quenching promoting effect. 0.005% or less is more preferable.
- the balance of the base steel plate is made of Fe and inevitable impurity elements.
- Inevitable impurities include N, Cr, Cu, Sn, Ni, Ca, Zn, Co, As, Sb, Pb, Se and the like in addition to the above.
- N is an element that forms coarse precipitates such as TiN and causes a reduction in local elongation.
- N is preferably reduced as much as possible. If the N content exceeds 0.01%, formability may be reduced due to coarse nitride formation. Therefore, the N content is preferably 0.01% or less.
- An alloyed hot-dip galvanized layer (hereinafter also referred to simply as a Zn-plated layer) is a plated layer mainly composed of an Fe—Zn alloy formed by diffusion of Fe in a base steel sheet during Zn plating by an alloying reaction. , Provided on the base steel plate.
- the Zn plating layer contains 7 to 15% Fe, and contains at least 0.01% by mass of a precipitate containing one or more selected from the group consisting of Ti, Nb, V, Mo and W. It is the layer which contains above and the balance consists of Zn and inevitable impurities.
- the reasons for limiting the component composition of the Zn plating layer will be described.
- the Fe content in the Zn plating layer is less than 7.0% by mass, the Zn—Fe alloying reaction is insufficient, so that the precipitate does not sufficiently diffuse from the base steel plate to the Zn plating layer. Adhesion improvement effect after painting does not appear.
- the Fe content exceeds 15.0% by mass the Zn-Fe alloying reaction proceeds excessively, and a brittle ⁇ phase is formed near the interface between the Zn plating layer and the base steel sheet, resulting in a deterioration in chipping resistance. To do. Therefore, the Fe content in the Zn plating layer is 7.0 to 15.0%.
- the Fe content in the Zn plating layer can be measured by ICP emission analysis.
- Precipitate containing one or more selected from the group consisting of Ti, Nb, V, Mo and W By dispersing a predetermined amount of a precipitate containing one or more selected from the group consisting of Ti, Nb, V, Mo and W in the Zn plating layer, while ensuring corrosion resistance, chipping resistance, coating An alloyed hot-dip galvanized steel sheet having excellent post-adhesion is obtained.
- the content of precipitates containing Ti, Nb, V, Mo and W present in the Zn plating layer is 0.01% or more. If it is the said range, the galvannealed steel plate which shows a desired characteristic will be obtained.
- the content of precipitates is less than 0.01% by mass, there are few precipitates present in the Zn plating layer, and the effect of improving chipping resistance and adhesion after coating cannot be obtained.
- the upper limit of the content of the precipitate is not particularly limited, but if too much precipitate is contained in the Zn plating layer, the corrosion resistance of the Zn plating layer itself cannot be secured, or there are fine cracks in the Zn plating layer. Since it may arise and a Zn plating layer may become weak, 1.0 mass% or less is desirable.
- a method of selectively dissolving the Zn plating layer and extracting the precipitate as a residue and performing quantitative analysis is excellent, but the analysis method is not particularly limited.
- the precipitate includes one or more selected from the group consisting of Ti, Nb, V, Mo, and W.
- the precipitates are mainly carbides in many cases, but nitrides, carbonitrides, sulfides, etc. are also precipitated depending on chemical components.
- the average particle size of the precipitate is not particularly limited, but is excellent in the pinning effect of cracks generated in the Zn plating layer, has a greater effect of improving chipping resistance, and functions more as each generation site of the zinc phosphate crystal film And it is preferable that it is 50 nm or less from the point with the larger improvement effect of adhesiveness after coating. Of these, 3 to 20 nm is preferable in that the above effect is more excellent.
- the method for measuring the particle size of the precipitate is not particularly limited. For example, after processing the cross section of the Zn plating layer into a thin piece using FIB (focused ion beam), the particle size of each particle is measured by TEM observation. To do.
- the average particle size of the precipitate is obtained by arbitrarily measuring the diameter of 10 or more precipitates and then arithmetically averaging them.
- an equivalent circle diameter is used.
- the “equivalent circle diameter” is a diameter of the circle when the shape of the precipitate is assumed to be a circle having the same projected area as the projected area of the precipitate.
- the distribution state of the precipitates in the Zn plating layer is not particularly limited, and the precipitates may be concentrated near the interface between the Zn plating layer and the base steel plate, or may be dispersed throughout the Zn plating layer.
- the shape of the precipitate is not particularly limited, and may be a spherical shape, an elliptical spherical shape, or the like.
- the adhesion amount of the Zn plating layer is desirably 10 g / m 2 or more in terms of the single-side adhesion amount of the base steel plate from the viewpoint of ensuring corrosion resistance, and is desirably 90 g / m 2 or less in terms of the single-side adhesion amount from the viewpoint of cost and plating adhesion.
- the manufacturing method of the alloyed hot-dip galvanized steel sheet described above is not particularly limited, and any method may be adopted as long as a Zn plating layer containing a predetermined precipitate is formed on a predetermined base material steel sheet.
- the manufacturing method of the galvannealed steel plate shown with the flowchart of FIG. 1 is preferable at the point from which a desired galvannealed steel plate is obtained with sufficient productivity.
- the manufacturing method includes a hot rolling step (S1), a winding step (S2), an annealing step (S3), a plating step (S4), and an alloying treatment step (S5).
- the hot rolling step S1 is a process of heating a steel slab (including an ingot, a slab, and a thin slab) having the component composition of the base steel plate described above in a heating furnace and hot rolling in a rough rolling mill and a finish rolling mill. This is a process of turning the steel piece into a strip-shaped steel plate (strip).
- the steel slab used in the step S1 is, for example, melted molten steel that satisfies the composition of the base steel plate described above by a known melting method such as a converter, an electric furnace, etc. It is manufactured by casting by a known casting method.
- the steel slab When the steel slab is heated in the heating furnace in the step S1, it is preferably heated to a temperature range of 1100 to 1300 ° C, more preferably 1200 to 1250 ° C. If it is in the said range, it is preferable at the point of ensuring of finish rolling temperature.
- the heated steel material is roughly rolled by a roughing mill and then finish-rolled by a finishing mill to form a hot-rolled steel sheet.
- the finish rolling finish temperature in finish rolling is preferably 850 ° C. or higher, and more preferably 900 ° C. or higher. If it is the said temperature range, it is preferable at the point of relaxation of rolling load.
- the thickness of the steel sheet after hot rolling is not particularly limited, but is preferably about 1.4 to 4.0 mm.
- the winding process S2 is a process for winding the steel sheet hot-rolled in the hot rolling process S1.
- a winding temperature in a temperature range of 540 ° C. or lower.
- By carrying out winding at the winding temperature generation of internal oxides containing easily oxidizable elements on the surface of the hot-rolled steel sheet is suppressed, and as a result, chipping resistance of the galvannealed steel sheet and after coating This leads to improved adhesion.
- a minimum of coiling temperature it is preferable that it is 100 degreeC or more. If it is more than this temperature, the water used at the time of cooling after hot rolling can evaporate and it can suppress that water is stored in a coil, As a result, corrosion of a steel plate can be suppressed more.
- the surface cleaning step is a step of pickling or degreasing the surface of the steel sheet obtained in step S2.
- the cold rolling step is a step of cold rolling the steel plate obtained in the above step S2 or the steel plate that has been pickled or degreased. By performing cold rolling, a steel plate having a predetermined thickness can be obtained. Since cold-rolled steel sheets may have rolling oil or iron powder attached thereto, they may be washed with alkali after cold rolling as necessary.
- the annealing step S3 is a step of performing an annealing process on the hot-rolled steel sheet obtained in the winding step S2. Annealing is performed in order to reduce the surface oxide film on the surface of the hot-rolled steel sheet and improve the plateability, and a desired effect can be obtained if it is within the above temperature range.
- the annealing treatment is preferably carried out until the maximum temperature reached by the hot-rolled steel sheet reaches 500 to 800 ° C, and more preferably 650 to 750 ° C. Further, after leaving the annealing step S3, the steel plate is cooled and immersed in the plating bath at a predetermined intrusion plate temperature.
- the cooling rate from the cooling zone to the plating bath during this period is 0.1 to 2.0 ° C. / It is desirable to be sec.
- Ti, Nb, V, Mo, and W in an undeposited state during hot rolling are formed as fine precipitates (particularly fine carbides). It precipitates on the steel sheet surface layer and the inside thereof to obtain a desired strength and increase the amount of precipitates diffused into the Zn plating layer.
- the atmosphere in which the annealing treatment is performed is usually performed in a reducing atmosphere, and more specifically, an atmosphere having an H 2 concentration of 2 to 25 vol% and a dew point of ⁇ 10 ° C. or less is preferable. If the H 2 concentration is less than 2 vol%, the reduction is insufficient and the plating property is lowered. On the other hand, even if the H 2 concentration is higher than 25%, the effect is saturated and the processing cost is increased, which is economically disadvantageous. On the other hand, when the dew point is higher than -10 ° C, the reduction is insufficient and the plating property is lowered.
- the balance other than H 2 is preferably an inert gas such as N 2 .
- the plating step S4 is a step in which a hot-dip galvanized treatment for forming a hot-dip galvanized layer on the surface of the hot-rolled steel plate is performed on the hot-rolled steel plate annealed in the annealing step S3.
- the plating treatment is preferably performed on a continuous hot dip galvanizing line.
- the procedure of the hot dip galvanizing treatment is not particularly limited, and a known method can be used.
- the hot-rolled steel sheet that has undergone the annealing step S3 is preferably cooled to the vicinity of the plating bath temperature (temperature range of 450 to 550 ° C.) and immersed in a hot dip galvanizing bath.
- the intrusion plate temperature is more preferably 470 ° C. or more from the viewpoint of promoting the diffusion of fine precipitates to the plating layer.
- the Al concentration in the hot dip galvanizing bath is preferably 0.10 to 0.22% by mass.
- wiping for adjusting the zinc adhesion amount on the surface of the hot rolled steel sheet may be performed as necessary.
- the alloying treatment step S5 is a step of forming a predetermined Zn plating layer by applying an alloying treatment to the hot-rolled steel sheet that has undergone the plating step S4.
- the temperature range during the alloying treatment is preferably 350 to 550 ° C., more preferably 400 to 520 ° C., and further preferably 450 to 520 ° C. from the viewpoint of promoting the diffusion of fine precipitates to the plating layer.
- the rate of temperature rise until reaching the alloying treatment temperature, the holding time at the alloying treatment temperature, the cooling rate after holding, etc. are not particularly limited.
- the heating means in the alloying treatment may be any means such as radiant heating, high frequency induction heating, energization heating, etc., as long as the Zn plating layer of the above form can be formed.
- the alloyed hot-dip galvanized steel sheet obtained by the above procedure is excellent in workability and corrosion resistance, as well as chipping resistance and adhesion after coating. Further, the surface of the alloyed hot-dip galvanized steel sheet may be subjected to post-treatment such as rust prevention treatment (for example, chromate treatment or chromium-free treatment), phosphate treatment, resin film coating, etc., as necessary. It is possible to apply rust preventive oil.
- rust prevention treatment for example, chromate treatment or chromium-free treatment
- phosphate treatment for example, resin film coating, etc.
- the obtained hot-rolled steel sheet is subjected to annealing treatment, plating treatment and alloying treatment. More specifically, first, in the CGL line, the hot-rolled steel sheet is subjected to the annealing temperatures shown in Table 2 (corresponding to the maximum steel sheet temperature) under a dew point of ⁇ 35 ° C. and 5% H 2 —N 2 atmosphere. Then, reduction annealing before plating is performed, and then the hot-rolled steel sheet is cooled to 470 ° C. at a cooling rate of 0.3 ° C./sec after the cooling zone, and then a hot dip galvanizing bath (bath composition: Zn) with a bath temperature of 460 ° C.
- bath composition bath composition: Zn
- the plating treatment was performed by immersing in -0.13 mass% Al-0.03 mass% Fe). After the hot dip galvanizing treatment, an alloying treatment was carried out at an alloying treatment temperature shown in Table 2 for about 20 seconds to produce an alloyed hot dip galvanized steel sheet.
- the manufactured alloyed hot-dip galvanized steel sheet was processed into thin pieces by using FIB (focused ion beam) and the cross section in the vicinity of the interface between the Zn plating layer and the steel sheet was subjected to TEM observation and composition analysis by EDX. At other levels, carbide deposits were observed in the Zn plating layer. Further, in order to measure the amount of precipitates in the Zn plating layer, electrolytic extraction with 10% acetylacetone-1% tetramethylammonium chloride-methanol electrolyte (AA electrolyte) was performed. At this time, in order to selectively dissolve the Zn plating layer, electrolysis was performed by constant potential electrolysis in which zinc was dissolved and iron was not dissolved. The entire amount of the obtained extraction residue was dissolved, and the amount of precipitates containing Ti, Nb, V, M, and W was measured by ICP analysis.
- FIB focused ion beam
- the Fe content in the Zn plating layer was measured by first dissolving and removing only the Zn plating layer with a 5% HCl aqueous solution to which an inhibitor was added, and then analyzing the Fe concentration in the solution by ICP. Moreover, the plating adhesion amount was measured from the weight difference before and after removing the Zn plating layer. The average particle size of the precipitate in the Zn plating layer was confirmed by processing the section of the Zn plating layer into a thin piece by FIB, then performing TEM observation and performing composition analysis by EDX.
- Chip resistance Regarding the chipping resistance of the alloyed hot-dip galvanized steel sheet, a phosphate chemical conversion treatment was carried out using a commercially available phosphate chemical treatment solution (manufactured by Nihon Parkerizing Co., Ltd.) for a test piece cut to a size of 70 mm ⁇ 150 mm. Then, three-coat coating (total film thickness 100 ⁇ m) of cationic electrodeposition coating (manufactured by Nippon Paint) (film thickness 20 ⁇ 2 ⁇ m), intermediate coating (manufactured by Nippon Paint), and top coating (manufactured by Nippon Paint) gave.
- a commercially available phosphate chemical treatment solution manufactured by Nihon Parkerizing Co., Ltd.
- this coated plate was cooled and held at ⁇ 20 ° C., and a chipping test was performed in which a crushed stone for roads having a diameter of 4 to 6 ⁇ m collided under a condition of an air pressure of 2.0 kgf / cm 2 with a gravel tester. Was measured. The obtained results were judged according to the following criteria, and ⁇ and ⁇ were judged good. The results are shown in Table 2.
- ⁇ Average peel diameter of less than 1.5 mm
- ⁇ Average peel diameter of 1.5 mm or more and less than 3.0 mm
- ⁇ Average peel diameter of 3.0 mm or more
- the above measurements were made and the arithmetic average was obtained.
- a circle equivalent diameter is used.
- the “equivalent circle diameter” is the diameter of the circle when the shape of the peeled portion is assumed to be a circle having the same projected area as the projected area of the peeled portion.
- a phosphate chemical conversion treatment was carried out using a commercially available phosphate chemical treatment solution (manufactured by Nihon Parkerizing Co., Ltd.) for a test piece cut to a size of 70 mm ⁇ 150 mm. Thereafter, cationic electrodeposition coating (manufactured by Nippon Paint Co., Ltd.) (film thickness 20 ⁇ 2 ⁇ m) was applied. Thereafter, this coated plate was immersed in distilled water heated to 40 ° C. for 500 hours, and then subjected to a cross-cut test method of JIS K5400 to measure the coating film residual rate.
- the alloyed hot-dip galvanized steel sheet of the present invention was all excellent in chipping resistance, adhesion after coating, and corrosion resistance. On the other hand, in the comparative examples (levels 8, 12, and 15) not satisfying the scope of the present invention, any evaluation was low.
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Abstract
Description
例えば、特許文献1では、質量%で、C:0.02~0.06%、Si≦0.3%、Mn:0.5~2.0%、P≦0.06%、S≦0.005%、Al≦0.06%、N≦0.006%、Mo:0.05~0.5%、Ti:0.03~0.14%を含み、残部が実質的にFeからなる鋼を溶製し、仕上げ圧延終了温度880℃以上、巻取温度570℃以上の条件で熱間圧延を行うことで、実質的にフェライト単相組織であり、平均粒径10nm未満のTiおよびMoを含む炭化物が分散析出していることを特徴とする、引張強度が590MPa以上の加工性に優れた高張力後鋼板およびその製造方法が開示されている。
また、特許文献2では、質量%で、C:0.01~0.1%、Si≦0.3%、Mn:0.2~2.0%、P≦0.04%、S≦0.02%、Al≦0.1%、N≦0.006%、Ti:0.03~0.2%を含み、かつMo≦0.5%およびW≦1.0%のうち1種以上を含み、残部がFeおよび不可避的不純物からなる鋼を溶製し、オーステナイト単相域で熱間圧延し、550℃以上で巻取り、フェライト単相の熱延鋼板を製造後、さらにスケール除去し、そのまま溶融亜鉛系めっきを施すことで、質量%で、4.8C+4.2Si+0.4Mn+2Ti≦2.5を満たし、組織が面積比率で98%以上のフェライトであり、原子比で、(Mo+W)/(Ti+Mo+W)≧0.2を満たす範囲で、Tiと、MoおよびWのうち1種以上とを含む10nm未満の析出物が分散して存在することを特徴とする、溶融亜鉛系めっき高張力熱延鋼板の製造方法が開示されている。
さらに、特許文献4においては、所定の凹凸を有する冷延鋼板上に、合金化溶融亜鉛めっき皮膜を設けることにより、めっき密着性を向上させる方法が開示されている。
特許文献1および2では、TiとMoなどを含む微細な炭化物をフェライト中に析出させるため、仕上げ圧延終了後、550℃以上の巻取温度(以下、CTとも称する)で巻取りを行う必要がある。Si、Mnなど、Feよりも酸化しやすい元素(以下、易酸化性元素)を含有する母材鋼板に対し、このような高CT条件下で巻取り処理を行った場合、母材鋼板表層部に易酸化性元素を含む内部酸化物が生成される。結果として、その後溶融亜鉛めっき処理や合金化処理において、過度にZn-Fe合金化反応が促進され、めっき密着性が劣化するという問題が生じる。
また、自動車用鋼板では走行中に小石などによるチッピングの衝撃により塗装やめっき皮膜が剥がれるといった現象が起こることがあるが、過度なZn-Fe合金化反応はめっき皮膜の耐チッピング性の劣化も招く。さらに、母材鋼板として熱延鋼板を用いた場合、冷延鋼板と比較して表面の凹凸が大きいことから、塗膜形成の前に実施される化成処理工程においてりん酸亜鉛結晶皮膜が厚く成長しやすく、塗装後の塗膜-めっき層界面における密着性に劣るという問題がある。
さらに、特許文献4では、母材鋼板に熱延鋼板を用いた場合、表面の凹凸が大きいため表面の粗度の制御が困難である。さらに、表面の粗度が大きくなるとりん酸亜鉛結晶皮膜が厚く成長しやすくなり、塗膜との密着性を十分に確保できない。
より具体的には、耐チッピング性が向上する原因としては、合金化溶融亜鉛めっき層がチッピングによる衝撃を受け、めっき-鋼板母材界面にクラックが発生する時、合金化溶融亜鉛めっき層中の所定の析出物がクラック発生部でピン止め効果を有し、このピン止め効果によりクラックの伝播がとまり、大きな剥離に至らないためであると推測される。
また、合金化溶融亜鉛めっき層中に所定の析出物を分散させることで、熱延鋼板のような表面の凹凸の大きな母材鋼板を用いた場合でも、塗装前に合金化溶融亜鉛めっき層上に設けられる下地層であるりん酸亜鉛結晶皮膜中のりん酸亜鉛結晶が過度に厚く形成することなく、微細な結晶皮膜となり、結果として塗装後密着性が向上するという知見も見出した。この理由として、合金化溶融亜鉛めっき層中の特に合金化溶融亜鉛めっき層表層側(母材鋼板側とは反対側)に存在する所定の析出物がりん酸亜鉛結晶の核生成サイトとなることで、高密度で微細なりん酸亜鉛結晶が成長し、塗膜と合金化溶融亜鉛めっき層とのアンカー効果が十分に発揮されたためと考えられる。
本発明は、上記知見に基づいて見出されたもので、その要旨とするところは、以下のとおりである。
Ti:0.03%以上0.40%以下、Nb:0.001%以上0.200%以下、V:0.001%以上0.500%以下、Mo:0.01%以上0.50%以下、およびW:0.001%以上0.200%以下のうちの1種または2種以上を含有し、残部がFeおよび不可避的不純物からなる成分組成を有する母材鋼板と、
前記母材鋼板表面上に設けられた質量%で7~15%のFeを含有する合金化溶融亜鉛めっき層とを有する合金化溶融亜鉛めっき鋼板において、
前記合金化溶融亜鉛めっき層中にTi、Nb、V、MoおよびWからなる群から選ばれる1種または2種以上を含む析出物を少なくとも質量%で0.01%以上含有することを特徴とする合金化溶融亜鉛めっき鋼板。
本発明の合金化溶融亜鉛めっき鋼板は、所定の成分組成を有する母材鋼板と、その母材鋼板上に設けられた所定の析出物を含む合金化溶融亜鉛めっき層とを有する。
以下では、母材鋼板および合金化溶融亜鉛めっき層についてそれぞれ詳述する。
なお、後述する成分に関する「%」表示は特に断らない限り質量%を意味するものとする。
合金化溶融亜鉛めっき鋼板中の母材鋼板は、C:0.02%以上0.30%以下、Si:0.01%以上2.50%以下、Mn:0.1%以上3.0%以下、P:0.003%以上0.080%以下、S:0.01%以下、およびAl:0.001%以上0.200%以下を含有すると共に、Ti:0.03%以上0.40%以下、Nb:0.001%以上0.200%以下、V:0.001%以上0.500%以下、Mo:0.01%以上0.50%以下、およびW:0.001%以上0.200%以下のうちの1種または2種以上を含有し、残部がFeおよび不可避的不純物からなる成分組成を有する。
以下、母材鋼板の成分組成の限定理由について説明する。
Cは母材鋼板中に炭化物を析出させ、母材鋼板の強度を高めるために必要な元素であり、0.02%以上の含有が必要である。一方、Cの含有量が0.30%を超えると溶接性が劣化する。そのため、C含有量は0.02%以上0.30%以下である。
Siは固溶強化元素として有効であり、強化効果が現れるためには0.01%以上含有することが好ましい。一方、Siが2.50%を超えて多量に含有させるとCGL(溶融亜鉛メッキ鋼板製造設備)焼鈍過程においてSiの酸化物が母材鋼板表面に濃化し、不めっき欠陥発生やめっき密着性劣化の原因となる。そのため、Si含有量は0.01%以上2.50%以下である。
Mnは母材鋼板の強度上昇のために添加し、強化効果が現れるためには0.1%以上含有することが好ましく、0.6%以上含有することがさらに好ましい。一方、Mnが3.0%を超えて添加させるとCGL焼鈍過程においてMnの酸化物が母材鋼板表面に濃化し、不めっき欠陥発生やめっき密着性劣化の原因となる。そのため、Mn含有量は0.1%以上3.0%以下である。
Pは不可避的に含有される元素のひとつであり、鋼板の強化に有効であり、その効果は0.003%以上で得られると共に、その含有量を0.003%未満にするためにはコスト増大が懸念される。一方、Pが0.080%を越えて含有されると溶接性が劣化すると共に、表面品質が劣化する。また、合金化処理時には合金化処理温度をより高くしないと所望の合金化度とすることができないが、合金化処理温度を上昇させると母材鋼板の延性が劣化すると同時に合金化溶融亜鉛めっき層の密着性が劣化する。そのため、P含有量は0.003%以上0.08%以下である。
Sは粒界に偏析またはMnSが多量に生成した場合、靭性を低下させるため、含有量を0.01%以下とする必要がある。そして、S含有量の下限は特に限定されず、不純物程度であってもよい。
Alは溶鋼の脱酸を目的に添加されるが、その含有量が0.001%未満の場合、その目的が達成されない。一方、0.200%を越えて含有させると、介在物が多量に発生し、鋼板の疵の原因となる。そのため、Al含有量は0.001%以上0.200%以下である。
(Nb:0.001%以上0.200%以下)
(V:0.001%以上0.500%以下)
(Mo:0.01%以上0.50%以下)
(W:0.001%以上0.200%以下)
Ti、Nb、V、MoおよびWは、母材鋼板中に析出物(特に、炭化物)を析出させるために必要な元素であり、これらの元素からなる群から選ばれる1種または2種以上を添加する。通常、これらの元素は、母材鋼板中でこれらの元素を含む析出物の形で含有される場合が多い。
これらの元素のなかで、特にTiは析出強化能が高く、コストの観点からも有効な元素である。しかしながら、添加量が0.03%未満では合金化溶融亜鉛めっき層中に析出物(特に、炭化物)を含有させるために必要な母材鋼板中の析出物量が不十分であり、0.40%を超えるとその効果は飽和し、コストアップとなる。そのため、Ti含有量は、0.03%以上0.40%以下である。
なお、Nb、V、Mo、Wについても上記Tiの含有範囲の上限および下限に関する同様の理由から、Nb量は0.001~0.200%、V量は0.001~0.500%、Mo量は0.01~0.50%、W量は0.001~0.200%である。
Bは焼き入れ性向上のために加えられる任意に加えられる元素であり、焼き入れ促進効果と共にめっき密着性がより優れる点で、0%以上0.005%以下が好ましく、0.0005%以上0.005%以下がより好ましい。
なお、Nは、TiN等の粗大な析出物を形成し、局部伸び低下を引き起こす元素であり、本発明では、できるだけ低減することが好ましい。Nの含有量が0.01%を超えると、粗大な窒化物形成により成形性を低下させる場合がある。このため、Nの含有量は0.01%以下とすることが好ましい。
合金化溶融亜鉛めっき層(以後、単にZnめっき層とも称する)は、合金化反応によってZnめっき中に母材鋼板中のFeが拡散してできたFe-Zn合金を主体としためっき層であり、上記母材鋼板上に設けられる。該Znめっき層は、7~15%のFeを含有し、Ti、Nb、V、MoおよびWからなる群から選ばれる1種または2種以上を含む析出物を少なくとも質量%で0.01%以上含有し、残部がZnおよび不可避的不純物からなる層である。
以下、Znめっき層の成分組成の限定理由について説明する。
Znめっき層中のFe含有率が7.0質量%未満では、Zn-Fe合金化反応が不十分なため、母材鋼板からZnめっき層へ析出物が十分に拡散せず、耐チッピング性や塗装後密着性向上効果が発現しない。また、Fe含有率が15.0質量%を超えるとZn-Fe合金化反応が過剰に進行し、Znめっき層と母材鋼板の界面付近に脆いΓ相が厚く生成され、耐チッピング性が劣化する。そのため、Znめっき層中におけるFe含有量は、7.0~15.0%である。
なお、Znめっき層中のFe含有量は、ICP発光分析法により測定することができる。
Znめっき層中にTi、Nb、V、MoおよびWからなる群から選ばれる1種または2種以上を含む析出物を所定量分散させることで、耐食性を確保しながらも、耐チッピング性、塗装後密着性に優れる合金化溶融亜鉛めっき鋼板が得られる。
Znめっき層中に存在するTi、Nb、V、MoおよびWを含む析出物の含有量は、0.01%以上である。上記範囲であれば、所望の特性を示す合金化溶融亜鉛めっき鋼板が得られる。
一方、析出物の含有量が0.01質量%未満の場合、Znめっき層中に存在する析出物が少なく、耐チッピング性、塗装後密着性の向上効果が得られない。析出物の含有量の上限は特に限定されないが、あまり多くの析出物をZnめっき層中に含有すると、Znめっき層そのものの耐食性を確保できなくなる場合や、Znめっき層中で微細な亀裂などを生じ、Znめっき層がもろくなる場合があるため、1.0質量%以下が望ましい。
なお、析出物の存在量を確認するには、例えば、Znめっき層を選択的に溶解して析出物を残渣として抽出し、定量分析する方法が優れているが、分析方法は特に限定されない。
なお、析出物の粒径の測定方法は特に限定されず、例えば、FIB(集束イオンビーム)を用いてZnめっき層の断面を薄片に加工した後、TEM観察を行い各粒子の粒径を測定する。
また、上記析出物の平均粒子径は、任意に10個以上の析出物の直径を測定したうえで、これらを算術平均することによって得られる。なお、TEM写真上、析出物が円形状でない場合は、円相当径を用いる。「円相当径」とは、析出物の形状を、析出物の投影面積と同じ投影面積をもつ円と想定したときの当該円の直径である。
また、析出物の形状も特に限定されず、球状、楕円球状等の形状であってもよい。
上述した合金化溶融亜鉛めっき鋼板の製造方法は特に制限されず、所定の母材鋼板上に所定の析出物を含むZnめっき層が形成されれば、いかなる方法を採用してもよい。
なかでも、生産性よく所望の合金化溶融亜鉛めっき鋼板が得られる点で、図1のフローチャートで示される合金化溶融亜鉛めっき鋼板の製造方法が好ましい。該製造方法は、熱間圧延工程(S1)と、巻き取り工程(S2)と、焼鈍工程(S3)と、めっき工程(S4)と、合金化処理工程(S5)とを有する。該製造方法であれば、微細な析出物が存在する母材鋼板に溶融亜鉛めっきを施し、その後の合金化処理によって鋼板表層からZnめっき層中へ析出物を拡散させることができ、結果として、析出物が分散したZnめっき層を得ることができる。
以下、各工程について詳述する。
熱間圧延工程S1は、上述した母材鋼板の成分組成を有する鋼片(インゴット、スラブ、薄スラブを含む)を加熱炉で加熱し、粗圧延機および仕上げ圧延機にて熱間圧延する過程を経て、鋼片を帯状の鋼板(ストリップ)にする工程である。
加熱された鋼素材は、粗圧延機にて粗圧延された後、仕上げ圧延機にて仕上げ圧延を施され熱延鋼板とされる。仕上げ圧延における仕上げ圧延終了温度は、850℃以上が好ましく、900℃以上がより好ましい。上記温度範囲であれば、圧延負荷の緩和の点で好ましい。
巻き取り工程S2は、上記熱間圧延工程S1で熱間圧延された鋼板を、巻き取る工程である。
該工程S2においては、540℃以下の温度域の巻取温度で鋼板を巻き取ることが好ましい。該巻取温度で巻き取りを実施することにより、熱延鋼板表面部での易酸化性元素を含む内部酸化物の生成が抑制され、結果として合金化溶融亜鉛めっき鋼板の耐チッピング性および塗装後密着性の向上につながる。
なお、巻取温度の下限としては、100℃以上であることが好ましい。該温度以上であれば、熱間圧延後の冷却時に使用される水が蒸発し、コイル内に水が貯まることを抑制でき、結果として鋼板の腐食をより抑制することができる。
表面洗浄工程は、上記工程S2で得られた鋼板の表面を酸洗または脱脂する工程である。表面洗浄工程を実施することにより、上記工程S2で得られた鋼板表面上に形成されるスケールの除去や、鋼板表面上の付着物を除去することができ、後述するめっき工程S4でのめっき不良がより抑制され、好ましい。
また、冷間圧延工程は、上記工程S2で得られた鋼板、または、酸洗もしくは脱脂された鋼板を、冷間圧延する工程である。冷間圧延が施されることによって、所定の板厚の鋼板を得ることができる。冷間圧延された鋼板には、圧延油や鉄粉が付着している場合があるため、必要に応じて、冷間圧延後アルカリで洗浄してもよい。
焼鈍工程S3は、上記巻き取り工程S2で得られた熱延鋼板に対して焼鈍処理を施す工程である。焼鈍は、熱延鋼板表面上の表面酸化膜を還元してめっき性を向上させるために行い、上記温度範囲内であれば所望の効果が得られる。
焼鈍処理は、熱延鋼板の最高到達温度が500~800℃になるまで実施することが好ましく、650~750℃がより好ましい。また、焼鈍工程S3を出た後、鋼板を冷却し、所定の侵入板温でめっき浴に浸漬するが、この間の冷却帯からめっき浴までの冷却速度は、0.1~2.0℃/secであることが望ましい。上記温度範囲で焼鈍し、上記冷却速度で冷却を実施することにより、熱間圧延時、未析出のまま固有状態のTi,Nb,V,Mo,Wが微細析出物(特に、微細炭化物)として鋼板表層および内部に析出し、所望の強度を得ると共にZnめっき層中に拡散させる析出物量を増加させる。
H2濃度が2vol%未満では、還元が不十分となりめっき性が低下する。一方、H2濃度が25%を超えて高くなっても、効果が飽和するうえ、処理コストが高くなり経済的に不利となる。また、露点が-10℃を超えて高くなると、還元が不十分となりめっき性が低下する。なお、H2以外の残部はN2などの不活性ガスとすることが好ましい。
めっき工程S4は、上記焼鈍工程S3にて焼鈍された熱延鋼板に対して、熱延鋼板表面に溶融亜鉛めっき層を形成するための溶融亜鉛めっき処理が施される工程である。めっき処理は連続溶融亜鉛めっきラインで行うのが好ましい。
溶融亜鉛めっき処理の手順は特に制限されず、公知の方法を使用できる。なかでも、上記焼鈍工程S3を経た熱延鋼板は、めっき浴温近傍(450~550℃の温度範囲)まで冷却され、溶融亜鉛めっき浴へ浸漬されることが好ましく、特に、めっき浴温への侵入板温は470℃以上とすることがめっき層への微細析出物の拡散を促進する観点でさらに好ましい。
なお、めっき付着量の制御を行いやすくするため、溶融亜鉛めっき浴中のAl濃度は0.10~0.22質量%とすることが好ましい。
合金化処理工程S5は、上記めっき工程S4を経た熱延鋼板に対して合金化処理を施すことにより、所定のZnめっき層を形成する工程である。
合金化処理時の温度範囲としては、350~550℃が好ましく、400~520℃がより好ましく、めっき層への微細析出物の拡散を促進する観点で450~520℃がさらに好ましい。上記温度範囲で合金化処理を行うことにより合金化溶融亜鉛めっき層に所定の析出物が形成され、結果として、得られる合金化溶融亜鉛めっき鋼板の耐チッピング性および塗装後密着性に優れる。
また、該合金化溶融亜鉛めっき鋼板の表面には、必要に応じて、防錆処理(例えば、クロメート処理やクロムフリー処理等)、リン酸塩処理、樹脂皮膜塗布等の後処理を施すことができ、防錆油を塗布することも可能である。
なお、表1中の数値の単位は、質量%である。
より具体的には、まず、CGLラインにて、露点-35℃、5%H2-N2雰囲気下で表2に示す焼鈍温度(鋼板最高到達温度に該当)になるまで熱延鋼板に対してめっき前還元焼鈍処理を行い、次に、熱延鋼板を冷却帯後の冷却速度0.3℃/secで470℃まで冷却した後、浴温460℃の溶融亜鉛めっき浴(浴組成:Zn-0.13質量%Al-0.03質量%Fe)に浸漬して、めっき処理を行った。
溶融亜鉛めっき処理後、表2に示す合金化処理温度で約20秒の合金化処理を行い、合金化溶融亜鉛めっき鋼板を製造した。
また、Znめっき層中の析出物量の測定のため、10%アセチルアセトン-1%テトラメチルアンモニウムクロライド-メタノール系電解液(AA系電解液)による電解抽出を行った。この際、Znめっき層を選択的に溶解するため、亜鉛を溶解し、かつ鉄を溶解しない定電位電解で電解した。得られた抽出残渣を全量溶解し、ICP分析により、Ti,Nb,V,M、Wを含む析出物量を測定した。
Znめっき層中における析出物の平均粒径は、FIBによりZnめっき層の断面を薄片に加工した後、TEM観察を行い、EDXによる組成分析を行うことにより確認を行った。
(加工性)
合金化溶融亜鉛めっき鋼板の加工性は、試料から圧延方向に対して90°方向にJIS5号引張試験片を採取し、JIS Z 2241の規定に準拠して、クロスヘッド速度10mm/min一定で引張試験を行い、引張り強度(TS/MPa)と伸び(EL%)を測定した。TS×EL≧15000のものを良好、TS×EL<15000のものを不良とした。結果を表2に示す。
合金化溶融亜鉛めっき鋼板の耐チッピング性については、寸法70mm×150mmに切り出した試験片について、市販のりん酸塩化成処理液(日本パーカライジング社製)を用いてりん酸塩化成処理を実施して、その後カチオン型電着塗装(日本ペイント社製)(膜厚20±2μm)、中塗り塗装(日本ペイント社製)、上塗り塗装(日本ペイント社製)の3コート塗装(合計膜厚100μm)を施した。その後、この塗装板を-20℃に冷却保持し、グラベロ試験機にて直径4~6μmの道路用砕石を、エアー圧2.0kgf/cm2の条件で衝突させるチッピング試験を行い、平均剥離径を測定した。得られた結果を下記基準で判定し、◎、○を良好と判定した。結果を表2に示す。
◎:平均剥離径1.5mm未満
○:平均剥離径1.5mm以上3.0mm未満
×:平均剥離径3.0mm以上
なお、平均剥離径は、塗装板の任意の剥離部分の直径を3箇所以上測定して、それらを算術平均して求めた。なお、剥離部分が円形状でない場合は、円相当径を用いる。「円相当径」とは、剥離部分の形状を、剥離部分の投影面積と同じ投影面積をもつ円と想定したときの当該円の直径である。
合金化溶融亜鉛めっき鋼板の塗装後密着性については、寸法70mm×150mmに切り出した試験片について、市販のりん酸塩化成処理液(日本パーカライジング社製)を用いてりん酸塩化成処理を実施して、その後カチオン型電着塗装(日本ペイント社製)(膜厚20±2μm)を施した。その後、この塗装板を40℃に加熱した蒸留水中に500時間浸漬した後、JIS K5400の碁盤目試験法に供し、塗膜残存率を測定した。得られた結果を下記基準で判定し、◎、○を良好と判定した。結果を表2に示す。
◎:塗膜残存率100%
○:塗膜残存率90%以上100%未満
×:塗膜残存率90%未満
合金化溶融亜鉛めっき鋼板の耐食性については、寸法70mm×150mmに切り出した試験片について、JIS Z 2371(2000年)に基づく塩水噴霧試験を3日間行い、クロム酸(濃度200g/L、80℃)を用いて腐食生成物を1分間洗浄除去し、片面あたりの試験前後のめっき腐食減量(g/m2・日)を重量法にて測定し、下記基準で評価した。結果を表2に示す。
○(良好):20g/m2・日未満
×(不良):20g/m2・日以上
一方、本発明の範囲を満たさない比較例(水準8、12、15)においては、いずれかの評価が低かった。
Claims (3)
- 質量%で、C:0.02%以上0.30%以下、Si:0.01%以上2.50%以下、Mn:0.1%以上3.0%以下、P:0.003%以上0.080%以下、S:0.01%以下、およびAl:0.001%以上0.200%以下を含有すると共に、
Ti:0.03%以上0.40%以下、Nb:0.001%以上0.200%以下、V:0.001%以上0.500%以下、Mo:0.01%以上0.50%以下、およびW:0.001%以上0.200%以下のうちの1種または2種以上を含有し、残部がFeおよび不可避的不純物からなる成分組成を有する母材鋼板と、
前記母材鋼板表面上に設けられた質量%で7~15%のFeを含有する合金化溶融亜鉛めっき層とを有する合金化溶融亜鉛めっき鋼板において、
前記合金化溶融亜鉛めっき層中にTi、Nb、V、MoおよびWからなる群から選ばれる1種または2種以上を含む析出物を少なくとも質量%で0.01%以上含有することを特徴とする合金化溶融亜鉛めっき鋼板。 - 前記析出物の平均粒子径が50nm以下である、請求項1に記載の合金化溶融亜鉛めっき鋼板。
- 前記析出物が炭化物である、請求項1または2に記載の合金化溶融亜鉛めっき鋼板。
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015187302A (ja) * | 2014-03-12 | 2015-10-29 | 新日鐵住金株式会社 | 鋼板および鋼板の製造方法 |
WO2017110030A1 (ja) * | 2015-12-25 | 2017-06-29 | Jfeスチール株式会社 | 高強度溶融めっき熱延鋼板およびその製造方法 |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5906753B2 (ja) * | 2011-02-24 | 2016-04-20 | Jfeスチール株式会社 | 合金化溶融亜鉛めっき鋼板 |
CN104498825A (zh) * | 2014-12-08 | 2015-04-08 | 青岛海信电器股份有限公司 | 一种钢板及其制作方法和液晶模组 |
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CN114280120A (zh) * | 2021-12-29 | 2022-04-05 | 上海大学 | 一种热镀锌汽车外板表面保护渣型线状缺陷的检测方法 |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04280953A (ja) | 1991-03-11 | 1992-10-06 | Sumitomo Metal Ind Ltd | 合金化溶融亜鉛めっき鋼板及びその製造法 |
JPH0681100A (ja) * | 1992-09-02 | 1994-03-22 | Kobe Steel Ltd | 合金化溶融亜鉛めつき鋼板の製造方法 |
JPH11200000A (ja) | 1998-01-06 | 1999-07-27 | Sumitomo Metal Ind Ltd | 耐低温チッピング性、加工性に優れた合金化溶融亜鉛めっき鋼板およびその製造方法 |
JP2002322543A (ja) | 2001-02-20 | 2002-11-08 | Nkk Corp | 加工性に優れた高張力鋼板ならびにその製造方法および加工方法 |
JP2003321736A (ja) | 2002-04-30 | 2003-11-14 | Jfe Steel Kk | 溶接性に優れた溶融亜鉛系めっき高張力熱延鋼板ならびにその製造方法および加工方法 |
WO2010061957A1 (ja) * | 2008-11-27 | 2010-06-03 | Jfeスチール株式会社 | 溶融亜鉛めっき鋼板およびその製造方法 |
WO2011122030A1 (ja) * | 2010-03-31 | 2011-10-06 | Jfeスチール株式会社 | 加工性に優れた高張力溶融亜鉛めっき鋼板およびその製造方法 |
JP2012188746A (ja) * | 2011-02-24 | 2012-10-04 | Jfe Steel Corp | 合金化溶融亜鉛めっき鋼板 |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0663119B2 (ja) * | 1987-02-19 | 1994-08-17 | 新日本製鐵株式会社 | 抵抗溶接性のすぐれた2層めっき鋼板 |
JP2001152288A (ja) * | 1999-11-19 | 2001-06-05 | Kobe Steel Ltd | 延性に優れる溶融亜鉛めっき鋼板およびその製造方法 |
JP2002309358A (ja) * | 2001-04-16 | 2002-10-23 | Kobe Steel Ltd | 加工性に優れた合金化溶融Znめっき鋼板 |
EP2343393B2 (en) * | 2002-03-01 | 2017-03-01 | JFE Steel Corporation | Surface treated steel plate and method for production thereof |
CN101048527A (zh) * | 2004-10-07 | 2007-10-03 | 杰富意钢铁株式会社 | 热镀锌钢板及其制造方法 |
CN101238234B (zh) * | 2005-08-05 | 2010-12-08 | 杰富意钢铁株式会社 | 高强度钢板及其制造方法 |
EP2009128A1 (en) * | 2007-06-29 | 2008-12-31 | ArcelorMittal France | Galvanized or galvannealed silicon steel |
KR101010971B1 (ko) * | 2008-03-24 | 2011-01-26 | 주식회사 포스코 | 저온 열처리 특성을 가지는 성형용 강판, 그 제조방법,이를 이용한 부품의 제조방법 및 제조된 부품 |
JP5609223B2 (ja) * | 2010-04-09 | 2014-10-22 | Jfeスチール株式会社 | 温間加工性に優れた高強度鋼板およびその製造方法 |
-
2012
- 2012-12-26 EP EP12864523.1A patent/EP2801634B1/en not_active Not-in-force
- 2012-12-26 WO PCT/JP2012/083671 patent/WO2013103117A1/ja active Application Filing
- 2012-12-26 KR KR1020147018067A patent/KR101668638B1/ko active IP Right Grant
- 2012-12-26 JP JP2013552416A patent/JP5783269B2/ja active Active
- 2012-12-26 US US14/370,502 patent/US20140349134A1/en not_active Abandoned
- 2012-12-26 CN CN201280066114.5A patent/CN104040001B/zh active Active
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04280953A (ja) | 1991-03-11 | 1992-10-06 | Sumitomo Metal Ind Ltd | 合金化溶融亜鉛めっき鋼板及びその製造法 |
JPH0681100A (ja) * | 1992-09-02 | 1994-03-22 | Kobe Steel Ltd | 合金化溶融亜鉛めつき鋼板の製造方法 |
JPH11200000A (ja) | 1998-01-06 | 1999-07-27 | Sumitomo Metal Ind Ltd | 耐低温チッピング性、加工性に優れた合金化溶融亜鉛めっき鋼板およびその製造方法 |
JP2002322543A (ja) | 2001-02-20 | 2002-11-08 | Nkk Corp | 加工性に優れた高張力鋼板ならびにその製造方法および加工方法 |
JP2003321736A (ja) | 2002-04-30 | 2003-11-14 | Jfe Steel Kk | 溶接性に優れた溶融亜鉛系めっき高張力熱延鋼板ならびにその製造方法および加工方法 |
WO2010061957A1 (ja) * | 2008-11-27 | 2010-06-03 | Jfeスチール株式会社 | 溶融亜鉛めっき鋼板およびその製造方法 |
WO2011122030A1 (ja) * | 2010-03-31 | 2011-10-06 | Jfeスチール株式会社 | 加工性に優れた高張力溶融亜鉛めっき鋼板およびその製造方法 |
JP2012188746A (ja) * | 2011-02-24 | 2012-10-04 | Jfe Steel Corp | 合金化溶融亜鉛めっき鋼板 |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015187302A (ja) * | 2014-03-12 | 2015-10-29 | 新日鐵住金株式会社 | 鋼板および鋼板の製造方法 |
WO2017110030A1 (ja) * | 2015-12-25 | 2017-06-29 | Jfeスチール株式会社 | 高強度溶融めっき熱延鋼板およびその製造方法 |
JP2017115212A (ja) * | 2015-12-25 | 2017-06-29 | Jfeスチール株式会社 | 表面外観及びめっき密着性に優れた高強度溶融めっき熱延鋼板およびその製造方法 |
CN108474092A (zh) * | 2015-12-25 | 2018-08-31 | 杰富意钢铁株式会社 | 高强度熔融镀敷热轧钢板及其制造方法 |
US11066721B2 (en) | 2015-12-25 | 2021-07-20 | Jfe Steel Corporation | High-strength hot-dip coated hot-rolled steel sheet and method for manufacturing the same |
Also Published As
Publication number | Publication date |
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KR101668638B1 (ko) | 2016-10-24 |
JPWO2013103117A1 (ja) | 2015-05-11 |
EP2801634A4 (en) | 2015-03-11 |
US20140349134A1 (en) | 2014-11-27 |
CN104040001A (zh) | 2014-09-10 |
KR20140097536A (ko) | 2014-08-06 |
JP5783269B2 (ja) | 2015-09-24 |
EP2801634B1 (en) | 2016-05-18 |
CN104040001B (zh) | 2016-03-09 |
EP2801634A1 (en) | 2014-11-12 |
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