CN107109574A - Plating, processability and the excellent high-strength steel sheet of delayed fracture resistance characteristics and its manufacture method - Google Patents

Plating, processability and the excellent high-strength steel sheet of delayed fracture resistance characteristics and its manufacture method Download PDF

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Publication number
CN107109574A
CN107109574A CN201680005029.6A CN201680005029A CN107109574A CN 107109574 A CN107109574 A CN 107109574A CN 201680005029 A CN201680005029 A CN 201680005029A CN 107109574 A CN107109574 A CN 107109574A
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China
Prior art keywords
steel sheet
less
layer
oxide layer
mean depth
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201680005029.6A
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Chinese (zh)
Inventor
池田宗朗
二村裕
二村裕一
中屋道治
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Kobe Steel Ltd
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Kobe Steel Ltd
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Publication date
Application filed by Kobe Steel Ltd filed Critical Kobe Steel Ltd
Priority claimed from PCT/JP2016/050070 external-priority patent/WO2016111275A1/en
Publication of CN107109574A publication Critical patent/CN107109574A/en
Pending legal-status Critical Current

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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
    • 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
    • C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
    • C23C2/36—Elongated material
    • C23C2/40—Plates; Strips
    • 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
    • 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
    • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • 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
    • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B15/043—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of metal
    • 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
    • B32B15/18—Layered products comprising a layer of metal comprising iron or steel
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
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    • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • C21D1/76—Adjusting the composition of the atmosphere
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    • 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
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    • 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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    • C21D8/0236—Cold rolling
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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    • 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
    • C21D8/0257—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment with diffusion of elements, e.g. decarburising, nitriding
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    • 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
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    • 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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Abstract

The present invention provides equilibrium, the processability of bendability and hole expandability and excellent more than the 980MPa of delayed fracture resistance characteristics of a kind of plating, intensity and ductility hot-dip galvanized steel sheet and alloyed hot-dip galvanized steel plate.The high intensity coated steel sheet of the present invention is the coated steel sheet for having coating layer on the surface of base steel sheet, and containing defined composition of steel, also, from the interface between base steel sheet and coating layer, basad steel plate side is included successively：Soft layer, when the thickness of slab of the base steel sheet is set into t, less than 90% Vickers hardness of the Vickers hardness at the t/4 positions with the base steel sheet；And hard layer, martensite and bainite and ferrite are contained in prescribed limit, wherein, the mean depth D of soft layer is more than 20 μm, and the mean depth d of inner oxide layer is for 4 μm less than D.

Description

Plating, processability and the excellent high-strength steel sheet of delayed fracture resistance characteristics and its system Make method
Technical field
It is more than 980MPa, plating, the equilibrium comprising intensity and ductility, bendability the present invention relates to a kind of tensile strength And the excellent high intensity coated steel sheet of processability and delayed fracture resistance characteristics and its manufacture method of hole expandability.The plating of the present invention Covering steel plate includes hot-dip galvanized steel sheet and alloyed hot-dip galvanized steel plate both sides.
Background technology
General hot-dip galvanized steel sheet and alloyed hot-dip galvanized steel plate are except quilt in the field such as automobile or transporter It is required that beyond high intensity, being also required the processabilities such as equilibrium, bendability and the hole expandability (stretch flangeability) of intensity and ductility It is excellent, further it is required that delayed fracture resistance characteristics are excellent.
In order to ensure high intensity and processability, the intensified elements such as Si or Mn are effectively more added in steel.So And, Si and Mn are easily oxidizable elements, due to forming the Si oxides on surface, Mn oxides, Si and Mn composite oxides Deng, the wetability of galvanizing by dipping is substantially deteriorated, occur non-plating the problems such as.
In this regard, for the coated steel sheet containing more Si or Mn, it is proposed that the technology of various raising processabilities etc..
For example, Patent Document 1 discloses the corrosion resistance that tensile strength is more than 590MPa and bendability and processing department Excellent hot-dip galvanized steel sheet.Specifically, in patent document 1, in order to suppress the boundary between steel plate and coating layer The generation and the damage of plated film of the flex-crack (flex crack) caused by the inner oxide layer formed in steel plate side are acted in face, by decarburization The growth of layer is set to be significantly faster than the growth of inner oxide layer.In addition, also disclosing so that because of decarburization in ferrite area The near surface tissue that the thinning mode of the thickness of the inner oxide layer of formation is controlled by.
In addition, Patent Document 2 discloses fatigue durability, resistance to hydrogen embrittlement (synonymous with delayed fracture resistance characteristics), curved The excellent tensile strength of song is more than 770MPa hot-dip galvanized steel sheet.Specifically, in patent document 2, steel plate portion bag Include：The soft layer directly contacted with the interface of coating layer；And the soft layer of the tissue maximum using ferrite as area occupation ratio.Separately Outside, the hot-dip galvanized steel sheet for meeting d/4≤D≤2d is also disclosed, wherein, D is the thickness of the soft layer, and d is to be present in steel Plate skin section and the depth counted containing more than a kind in Si and Mn of oxide from the interface of coating layer/substrate steel.
Patent Document 3 discloses the high intensity cold of more than the tension maximum intensity 700MPa with excellent bendability Rolled steel plate.Specifically, having been recorded in patent document 3 can soften steel plate top layer by implementing carbonization treatment, even Tension maximum intensity is more than 700MPa high strength cold rolled steel plate, is also resulted in excellent just as low intensive steel plate Bendability.
Patent Document 4 discloses in the case where not undermining ductility and intensity, making delayed fracture resistance characteristics excellent and Even the anisotropy of its delayed fracture resistance characteristics of thin plate also few high-strength hot-dip galvanized steel sheet.Specifically, in patent In document 4, in order to prevent the delayed fracture using the skin section of substrate steel sheet as starting point, the skin section of substrate steel sheet is set to hard The few decarburized layer of tissue, and it is used as the fine oxidation caught hydrogen position and played a role so that high density is scattered in its decarburized layer Thing.
It is Patent Document 5 discloses the tension maximum intensity that can obtain excellent formability and hydrogen embrittlement resistance More than 900MPa high-strength steel sheet.Specifically, recorded in patent document 5 due to having on steel plate top layer than in steel plate The soft decarburized layer in portion (softening layer), it is (resistance to therefore, it is possible to the hydrogen embrittlement resistance that obtains excellent just as low intensive steel plate Delayed fracture characteristic).
Prior art literature
Patent document
Patent document 1：Japanese Laid-Open Patent Publication 2011-231367
Patent document 2：Japanese patent gazette the 4943558th
Patent document 3：Japanese patent gazette the 5454746th
Patent document 4：Japanese patent gazette the 5352793rd
Patent document 5：Japanese Laid-Open Patent Publication 2011-111675
The content of the invention
The problem to be solved in the present invention
As described above, have been presented for up to now it is various make processability of the coated steel sheet containing more Si and Mn etc. improve Technology.However, it is expected that providing a kind of whole has various characteristics that the coated steel sheet is required, i.e. concurrently：More than 980MPa height Intensity, plating, the equilibrium of intensity and ductility, the technology of the processability of bendability and hole expandability and delayed fracture resistance characteristics.
The present invention makes in view of the foregoing, and its object is to provide the balanced, curved of a kind of plating, intensity and ductility The hot-dip galvanized steel sheet and alloying of the processability and excellent more than the 980MPa of delayed fracture resistance characteristics of song and hole expandability Hot-dip galvanized steel sheet and its manufacture method.
The solution used to solve the problem
The tensile strength involved in the present invention that can solve the problem that above mentioned problem is more than 980MPa high intensity coated steel sheet It is characterized by, it is the coated steel sheet for having dip galvanized or alloyed hot-dip zinc-coated layer on the surface of base steel sheet, (1) The base steel sheet contains C in terms of quality %：0.05% to 0.25%, Si：0.25% to 3%, Mn：1.5% to 4%, P：It is super Cross 0% and less than 0.1%, S：More than 0% and less than 0.05%, Al：0.005% to 1%, N：More than 0% and less than 0.01%, Surplus is iron and inevitable impurity, (2) from the interface between the base steel sheet and the coating layer, basad steel plate Side is included successively：Inner oxide layer, comprising selected from the oxide by least one of Si and the Mn group constituted；Soft layer, bag Containing the inner oxide layer, also, when the thickness of slab of the base steel sheet is set into t, the t/4 positions with the base steel sheet Vickers hardness less than 90% Vickers hardness；And hard layer, include horses of the 60 area % less than 95 area % Family name's body and bainite, more than 5 area % and below 40 area % polygonal ferrite, wherein, the average depth of the soft layer It is more than 20 μm to spend D, and the mean depth d of the inner oxide layer is for 4 μm less than the D, the high intensity plating steel The tensile strength of plate is more than 980MPa.
The present invention preferred embodiment in, the base steel sheet in terms of quality % also contain following (a)~(c) In at least one：(a) from by Cr：More than 0% and less than 1%, Mo：More than 0% and less than 1% and B：More than 0% and At least one selected in less than 0.01% group constituted；(b) from by Ti：More than 0% and less than 0.2%, Nb：More than 0% And less than 0.2% and V：At least one selected in the group constituted more than 0% and less than 0.2%；(c) from by Cu：More than 0% And less than 1% and Ni：At least one selected in the group constituted more than 0% and less than 1%.
The present invention preferred embodiment in, the mean depth d of the inner oxide layer is flat with the soft layer Equal depth D meets D ＞ 2d relation.
Furthermore it is possible to which the manufacture method of the invention for solving described problem is characterized by, for manufacturing described any High intensity coated steel sheet, the manufacture method includes successively：By the steel of the composition of steel described in satisfaction at a temperature of more than 600 DEG C The hot-rolled step that coiled sheet takes；Pickling and cold rolling step are carried out in the way of the mean depth d for making inner oxide layer retains more than 4 μm Suddenly；In oxidized zone, the step of with 0.9 to 1.4 air than being aoxidized；In zone of reduction, in (Ac1+ 50 DEG C of point) to (Ac3 + 20 DEG C of point) scope keep and the step of carry out soaking；And after soaking, will cool down stop temperature untill scope with 5 DEG C/ The step of average cooling rate more than second is cooled down.
In addition, can solve the problem that another manufacture method of the invention of described problem is characterized by, described for manufacturing Any high intensity coated steel sheet, the manufacture method includes successively：By the composition of steel described in satisfaction at a temperature of more than 500 DEG C Coiler plate hot-rolled step；The step of being incubated more than 80 minutes at a temperature of more than 500 DEG C；So that inner oxide layer The mode that mean depth d retains more than 4 μm carries out pickling and cold rolling step；In oxidized zone, with 0.9 to 1.4 air ratio The step of being aoxidized；In zone of reduction, in (Ac1+ 50 DEG C of point) to (Ac3+ 20 DEG C of point) scope keep and carry out the step of soaking Suddenly；And after soaking, the step that the scope cooled down untill stopping temperature is cooled down with more than 5 DEG C/sec of average cooling rate Suddenly.
The effect of invention
The coated steel sheet of the present invention is from the interface between coating layer and base steel sheet, and basad steel plate side includes successively： Include the inner oxide layer selected from the oxide by least one of Si and the Mn group constituted；Area comprising the inner oxide layer The soft layer in domain；And the hard layer beyond the soft layer is (as parent phase tissue, comprising 60 area % less than 95 faces Accumulate % martensite and bainite, more than 5 area % and below 40 area % polygonal ferrite), especially by internal oxidation The mean depth d of layer controls effectively to be utilized as hydrogen capture position for more than 4 μm thicker, therefore, it is possible to effectively suppress hydrogen It is crisp, the processability and delayed fracture resistance characteristics of equilibrium, bendability and hole expandability of intensity and ductility etc. is made excellent anti- Tensile strength is more than 980MPa high intensity coated steel sheet.It is preferred that the mean depth d due to suitably controlling inner oxide layer With the mean depth D of the soft layer in the region comprising inner oxide layer relation, therefore especially bendability and delayed fracture resistance Characteristic is further improved.
Brief description of the drawings
Fig. 1 is schematically illustrated in the coated steel sheet of the present invention, from the interface between coating layer and base steel sheet To the figure of the Rotating fields of base steel sheet side.
Fig. 2 is the explanation figure for determining the mean depth d of the inner oxide layer in the coated steel sheet of the present invention.
Fig. 3 is the figure located for illustrating the Vickers hardness in order to determine the mean depth D of soft layer and use.
Embodiment
The present inventor is broken to provide a kind of high intensity with more than 980MPa and plating, processability, resistance to delay It is excellent high intensity coated steel sheet to split characteristic and impact resistance absorbability, and wherein base steel sheet contains more Si and Mn, special Do not pay close attention to from the interface between coating layer and base steel sheet to the Rotating fields of base steel sheet side and research has been repeated.As a result It was found that, shown in the schematic diagram of Fig. 1 as be described hereinafter, if using following (I) and (II), inner oxide layer captures position as hydrogen Play a role, can effectively suppress hydrogen embrittlement, therefore, it is possible to realize desired purpose, and it is preferably that following (III) is appropriate Ground is controlled, then especially bendability and delayed fracture resistance characteristics is further improved, and completes the present invention, wherein, (I) makes certainly The Rotating fields of interface to base steel sheet side between coating layer and base steel sheet include possess inner oxide layer soft layer and Hard layer, the hard layer be the soft layer beyond layer, comprising 60 area % less than 95 area % martensite and Bainite, more than 5 area % and below 40 area % polygonal ferrite, wherein the inner oxide layer contains selected from by Si With the oxide of at least one of the Mn groups constituted；(II) controls the mean depth d of inner oxide layer as 4 thicker More than μm；(III) is the mean depth d of the inner oxide layer and the soft layer in the region comprising the inner oxide layer Mean depth D between relation.
In this manual, coated steel sheet includes hot-dip galvanized steel sheet and alloyed hot-dip galvanized steel plate both sides.In addition, In this specification, base steel sheet refers to the steel plate to be formed before dip galvanized and alloyed hot-dip zinc-coated layer, is different from described Coated steel sheet.
In addition, in this manual, high intensity refers to that tensile strength is more than 980MPa.
In addition, in this manual, excellent in workability refers to that equilibrium, bendability and the hole expandability of intensity and ductility are excellent. Specifically, when method described in using embodiment described later determines these characteristics, the qualified base of embodiment will be met Accurate is referred to as " excellent in workability ".
As described above, the coated steel sheet of the present invention has dip galvanized or alloyed hot-dip plating on the surface of base steel sheet Zinc layers (following, to represent them with coating layer sometimes).Also, the characteristic of the present invention is from base steel sheet and coating layer Between interface rise, basad steel plate side successively have following (A) to (C) Rotating fields.
(A) inner oxide layer：It is comprising the layer selected from the oxide by least one of Si and the Mn group constituted.It is interior The mean depth d of portion's oxide layer is 4 μm of mean depth D less than soft layer described in (B) described later.
(B) soft layer：It includes the inner oxide layer, when the thickness of slab of the base steel sheet is set into t, Vickers hardness Meet less than the 90% of the Vickers hardness at the t/4 positions of the base steel sheet.The mean depth D of soft layer is more than 20 μm.
(C) hard layer：It includes following tissue, i.e., comprising 60 area % less than 95 area % martensite and Bainite, more than 5 area % and below 40 area % polygonal ferrite.
Below, reference picture 1, explains the Rotating fields that (A) to (C) described in feature is assigned to the present invention successively.Such as Shown in Fig. 1, the interface of the Rotating fields of the side of base steel sheet 2 of coated steel sheet of the invention between coating layer 1 and base steel sheet 2 to The side of base steel sheet 2 is included：(B) soft layer 4；And the hard layer 5 of (C), the hard layer 5 is than soft layer 4 positioned at base steel sheet 2 The inside of side.The soft layer 4 of (B) includes the inner oxide layer 3 of (A).In addition, the soft layer 4 connects with the hard layer 5 Exist continuously.
(A) on inner oxide layer
First, being directly contacted with the part of coating layer 1 and the interface of base steel sheet 2, there is mean depth d to be more than 4 μm Inner oxide layer 3.Here, mean depth refers to the mean depth counted from the interface, will for its detailed assay method It is illustrated in embodiment described later using Fig. 2.
The inner oxide layer 3 contains：Oxide comprising at least one of Si and Mn；And because of Si and Mn formation oxygen Compound and Si and Mn depleted layers less solid solution Si and/or solid solution Mn around it.
The maximum of the present invention is characterised by controlling the mean depth d of the inner oxide layer 3 as more than 4 μm thicker. Accordingly, it can effectively be utilized the inner oxide layer as hydrogen capture position, hydrogen embrittlement can be suppressed, and improve bendability, reaming Property and delayed fracture resistance characteristics.
In addition, such as base steel sheet of the present invention containing more Si and Mn easily oxidizables element (company described later in annealing Oxidative reduction step in continuous hot-dip galvanizing line), Si oxides, Mn oxides, tool are easily formed on base steel sheet surface There is the oxide-film of Si and Mn composite oxides, plating can be reduced.In this regard, being used as its countermeasure, it is known to following method： Make the surface oxidation of base steel sheet under oxidizing atmosphere and generate after Fe oxide-films, being annealed in hydrogeneous atmosphere, (reduction is moved back Fire).It is furthermore also known that following method：Make easily oxidizable element by controlling furnace atmosphere as oxide and be fixed on base Inside the top layer of bottom steel plate, reduce the easily oxidizable element on the top layer for being solid-solubilized in base steel sheet, so as to prevent easily oxidizable member Element forms oxide-film on the surface of base steel sheet.
However, it can be seen from the result of study of the present inventor：For being plated to the base steel sheet containing more Si and Mn In the general oxidation-reduction method covered, under the nitrogen atmosphere in reduction, hydrogen is penetrated into base steel sheet, so as to occur caused by hydrogen embrittlement Bendability and hole expandability reduction, it is desirable to improve the reduction of these characteristics, effectively effectively using be selected from by Si and Mn structures Into at least one of group oxide.Specifically, it was found that the oxide can be used as hydrogen and capture position, it can be Prevent hydrogen from penetrating into base steel sheet during reduction, bendability and hole expandability and delayed fracture resistance characteristics can be improved, it is desirable to have Effect ground plays its effect, and integral is to form the mean depth d of the inner oxide layer containing the oxide thicker For more than 4 μm.
In the present invention, soft layer of the mean depth d of the inner oxide layer upper limit at least below (B) described later is averaged Depth D.The upper limit of the d is preferably less than 30 μm.Its reason is：Want to make inner oxide layer thickening, it is necessary in hot rolled coil Be held in for a long time in high-temperature area after taking, but be due to by the limitation in production efficiency and equipment, therefore probably turn into it is upper State preferred value.The d is more preferably less than 18 μm, more preferably less than 16 μm.In addition, the d be preferably 6 μm with On, more preferably more than 8 μm.
Moreover, in the present invention, it is preferred to：So that the mean depth d of the inner oxide layer and (B) described later soft layer The mean depth D mode of the relation relational expression that meets D ＞ 2d control the mean depth d of the inner oxide layer, accordingly, bending Property and delayed fracture resistance characteristics improve, especially bendability is further improved.In contrast, disclosed in described patent document 2 D/4≤D≤2d hot-dip galvanized steel sheet is met, wherein, the thickness D of depth d and soft layer present in oxide is substantially right Should be in the mean depth d and the mean depth D of soft layer of the inner oxide layer described in the present invention, the controlling party of patent document 2 Pin and the relational expression (D ＞ 2d) specified in the present invention are entirely different.Moreover, the patent document 2 is substantially described The scope of depth d on the basis of the relation of d/4≤D≤2d described in meeting present in control oxide, therefore do not have completely The basic conception controlled the mean depth d of inner oxide layer thicker for more than 4 μm shown in the present invention.Certainly, do not have yet The effect for playing position is captured as hydrogen accordingly and effectively is recorded, so that bendability, hole expandability and delayed fracture resistance characteristics are carried High effect of the invention.
In addition, in the present invention, it is desirable to by the mean depth d of inner oxide layer control be more than 4 μm, then need by The mean depth control of the inner oxide layer of cold-rolled steel sheet before into continuous hot-dipping galvanizing production line is more than 4 μm.In detail Content will be described in manufacture method below.Shown in embodiment i.e., as be described hereinafter, pickling, it is cold rolling after inner oxide layer quilt Inherit the inner oxide layer in the coated steel sheet finally obtained into after plating lines.
(B) on soft layer
In the present invention, as shown in figure 1, soft layer 4 is the layer in the region of the inner oxide layer 3 comprising (A), and dimension Family name's hardness meets less than the 90% of the Vickers hardness at the t/4 positions of base steel sheet 2.The detailed assay method of the Vickers hardness It is illustrated in the embodiment that will be described below.
The soft layer is the Vickers hardness soft tissue lower than the hard layer of (C) described later, and deformability is excellent, especially It improves bendability.That is, in bending machining, the skin section of base steel sheet turns into the starting point of fracture, but as representative of the present invention, By forming defined soft layer on the top layer of base steel sheet, especially improved bendability.Moreover, described soft by being formed Matter layer, the starting point that the oxide in (A) can be prevented to be broken when turning into bending machining can be enjoyed only described as hydrogen Capture the advantage at position.As a result, not only bendability is further improved, and delayed fracture resistance characteristics are also further improved.
The effect that formation in order to effectively play this soft layer is brought, the mean depth D of the soft layer is set For more than 20 μm.The D is preferably more than 22 μm, more preferably more than 24 μm.On the other hand, if the soft layer is averaged Depth D is blocked up, then the intensity decreases of coated steel sheet itself, it is therefore preferable that its upper limit is set into less than 100 μm.The D is more preferably For less than 60 μm.
(C) on hard layer
In the present invention, as shown in figure 1, hard layer formation is in the side of base steel sheet 2 of the soft layer 4 of (B), and wrap Following tissue is included, i.e., comprising 60 area % less than 95 area % martensite and bainite, more than 5 area % and 40 Below area % polygonal ferrite.The martensite of the hard layer 5 can also be the martensite after tempering.There is bainite Then intensity is more improved total area occupation ratio bigger (that is, ferritic area occupation ratio is smaller) with martensite, bainite and martensite Smaller (that is, ferritic area occupation ratio the is bigger) tendency that then ductility is more improved of total area occupation ratio.If in addition, ferritic area Rate diminishes, then intensity and the balanced variation of elongation percentage.Therefore, it is recommended that preferred area ratios of these tissues consider with it is desired Characteristic between relation and suitably set.For example, from the viewpoint of intensity is improved, preferably bainite and martensite is total Area occupation ratio is more than 80 area %, and ferritic total area occupation ratio is below 20 area %.Further, it is contemplated that improving intensity and extension Total area occupation ratio of the equilibrium of rate, preferably bainite and martensite is below 70 area %, and ferritic total area occupation ratio is 30 More than area %.
Hard layer, can also be in the range of the effect of the present invention not be undermined comprising during fabrication in addition to above-mentioned tissue The tissue being inevitably mixed into, such as retained austenite (Y), pearlite.The maximum tissue is also below 15 area %, It is more few better.In addition, described be organized in described in table 3 described later is " other ".
As long as in addition, the hard layer of the present invention is as described above in terms of total area, in 60 area % less than 95 Area % scope includes bainite and martensite, and the respective ratio of bainite and martensite is limited without any.It is former Because being：In the present invention, as long as meeting the necessary condition, it is possible to play the effect that the formation of hard layer is brought Really.Therefore, as long as the hard layer meets the necessary condition, bainite ＞ martensites, bainite=geneva can be met Any relation of body, bainite ＜ martensites.In addition, being only entirely free of the situation of martensite comprising bainite and only including Martensite and the situation that is entirely free of bainite are contained in the scope of the present invention.Consider from the viewpoint, described later In embodiment, bainite and martensite are not observed in difference, and only determine total area, and the result of the measure is shown in into table In 3.
Being explained above can most allow the present invention with feature from the interface of coating layer and base steel sheet, basad steel plate The Rotating fields of side.
Then, it is illustrated for composition of steel used in the present invention.
The coated steel sheet of the present invention contains C：0.05% to 0.25%, Si：0.25% to 3%, Mn：1.5% to 4%, P： More than 0% and less than 0.1%, S：More than 0% and less than 0.05%, Al：0.005% to 1%, N：More than 0% and 0.01% with Under, surplus is iron and inevitable impurity.
C：0.05% to 0.25%
C is to be used to improve hardenability, also brings hardening effect to martensite, is important member for the high intensity of steel Element.In order to effectively play this effect, the lower limit of C content is set to more than 0.05%.The lower limit of C content be preferably 0.08% with On, more preferably more than 0.10%.If however, adding C too much, the soft difference of hardness with hard phase becomes big, processing Property and delayed fracture resistance characteristics reduction, therefore the upper limit of C content is set to 0.25%.The upper limit of C content be preferably 0.2% with Under, more preferably less than 0.18%.
Si：0.25% to 3%
Si is the intensity that steel is improved by solution strengthening, and is effective element for the raising of processability. In addition, generation inner oxide layer, also with the effect for suppressing hydrogen embrittlement.In order to effectively play this effect, by the lower limit of Si contents It is set to more than 0.25%.The lower limit of Si contents is preferably more than 0.3%, and more preferably more than 0.5%, more preferably More than 0.7%.However, Si is ferrite generating elements, if adding Si too much, ferritic generation can not be suppressed, it is soft Matter phase and the difference of hardness of hard phase become big, processability reduction.Moreover, plating is also deteriorated, therefore the upper limit of Si contents is set to 3%.The upper limit of Si contents is preferably less than 2.5%, and more preferably less than 2.0%.
Mn：1.5% to 4%
Mn is that hardenability improves element, suppresses ferrite and bainite, generates martensite, contribute to high intensity.In order to This effect is effectively played, the lower limit of Mn contents is set to more than 1.5%.The lower limit of Mn contents is preferably more than 1.8%, more excellent Elect more than 2.0% as.If however, adding Mn too much, plating is reduced, and segregation also becomes notable.Further, can also Encourage P cyrystal boundary segregation.Therefore, the upper limit of Mn contents is set to 4%.The upper limit of Mn contents is preferably less than 3.5%.
P：More than 0% and less than 0.1%
P is the useful element of the reinforcing to steel as solution strengthening element.In order to effectively play this effect, P is contained The lower limit of amount is set to more than 0%.If however, adding too much, not only reducing processability, weldability can be also brought and tough The reduction of property, therefore its upper limit is set to less than 0.1%.P content is less to be advisable, and preferably less than 0.03%, more preferably Less than 0.015%.
S：More than 0% and less than 0.05%
S is the element inevitably contained, generates MnS sulfides, and the sulfide turns into the starting point of fracture, it is possible to Reduce processability.Therefore, the upper limit of S contents is set to less than 0.05%.S contents are less to be advisable, and preferably less than 0.01%, More preferably less than 0.008%.
Al：0.005% to 1%
Al works as deoxidier.In addition, Al and N are combined into as AlN, by making austenite particle diameter miniaturization, Improve processability and delayed fracture resistance characteristics.In order to effectively play this effect, by the lower limit of Al content be set to 0.005% with On.The lower limit of Al content is preferably more than 0.01%, and more preferably more than 0.02%.If however, adding Al too much, made The field trashes such as aluminum oxide increase and cause processability to reduce, and also bring the reduction of toughness.Therefore, the upper limit of Al content is set to 1%.The upper limit of Al content is preferably less than 0.8%, and more preferably less than 0.6%.
N：More than 0% and less than 0.01%
N is the element inevitably contained, but if content crosses at most processability reduction.Moreover, adding B in steel In the case of (boron), BN precipitates are generated, B hardenability raising effect is hindered, therefore are reduced as far as N and are advisable.Therefore, will The upper limit of N content is set to less than 0.01%.The upper limit of N content is preferably less than 0.008%, and more preferably less than 0.005%.
The coated steel sheet of the present invention contains the composition, and surplus is iron and inevitable impurity.
In addition, the present invention can also contain following selection element.
Selected from by Cr：More than 0% and less than 1%, Mo：More than 0% and less than 1% and B：More than 0% and less than 0.01% At least one of group of composition
These elements are the effective elements for the intensity of steel plate rises.These elements both can be added individually, It can be used together two or more.
Specifically, Cr improves hardenability, contributes to intensity to rise.Moreover, Cr suppresses the generation and growth of cementite, Help to improve bendability.In order to effectively play this effect, the preferred lower limit of Cr contents is set to more than 0.01%.So And, if adding Cr too much, plating reduction.And Cr carbide is generated too much, cause processability to reduce.Therefore, The upper limit of Cr contents is preferably less than 1%.More preferably less than 0.7%, more preferably less than 0.4%.
For high intensity effectively, therefore, the lower limit of Mo contents is preferably more than 0.01% to Mo.If however, mistake Mo is added more, then the effect saturation, uprises cost.Therefore, the Mo upper limit is preferably less than 1%.More preferably 0.5% Hereinafter, more preferably less than 0.3%.
B same with Mn is that hardenability improves element, is to suppress ferrite and bainite, generates martensite, contribute to high-strength The element of degreeization.In order to effectively play this effect, the lower limit of B content is preferably more than 0.0002%, more preferably More than 0.0010%.If however, B content is excessive, reducing hot-workability, therefore, the upper limit of B content is preferably 0.01% Below.More preferably less than 0.0070%, more preferably less than 0.0050%.
Selected from by Ti：More than 0% and less than 0.2%, Nb：More than 0% and less than 0.2% and V：More than 0% and 0.2% with At least one of group of lower composition
These elements be for the raising of the processability brought of tissue miniaturization and delayed fracture resistance characteristics effectively Element.These elements both can be added individually, can also and with two or more.
In order to effectively play above-mentioned effect, the respective lower limit of Ti, Nb, V is preferably more than 0.01%.If however, each The content of element is excessive, then generates ferrite, reduce processability, therefore, the upper limit of each element is preferably less than 0.2%.Respectively Element is more preferably less than 0.15%, more preferably less than 0.10%.
Selected from by Cu：More than 0% and less than 1% and Ni：At least one of group constituted more than 0% and less than 1%
Cu and Ni are the effective elements for high intensity.These elements both can be added individually, can be used together again.
In order to effectively play above-mentioned effect, the respective lower limit of Cu, Ni is preferably more than 0.01%.If however, each member The content of element is excessive, then reduces hot-workability, therefore, the upper limit of each element is preferably less than 1%.Each element is more preferably Less than 0.8%, more preferably less than 0.5%.
More than, the composition of steel of the present invention is illustrated.
Below, the method for the coated steel sheet of the manufacture present invention is illustrated.The manufacture method of the present invention includes：In heat Roll after batching, be not incubated and carry out immediately the first method of pickling；And be incubated after hot rolling reeling, then carry out pickling Second method.According to the presence or absence of insulation, first method (no insulation) and the hot-rolling coiling temperature of second method (having insulation) Lower limit is different, in addition the step of it is identical.It is described in detail below.
[the first manufacture method (no insulation)]
First manufacture method involved in the present invention is roughly divided into：Hot-rolled step；Pickling and cold-rolling step；And in Continuous Heat Oxidation step, reduction step and plating step in zinc immersion production line (CGL (Continuous Galvanizing Line)) Suddenly.Also, the characteristic of the present invention is to include successively：The steel of the composition of steel will be met at a temperature of more than 600 DEG C Coiled sheet takes, so as to obtain the hot-rolled step for the hot rolled steel plate for being formed with inner oxide layer；So that the mean depth d of inner oxide layer The mode for retaining more than 4 μm carries out pickling and cold rolling step；In oxidized zone, with 0.9 to 1.4 air than being aoxidized Step；In zone of reduction, in (Ac1+ 50 DEG C of point) to (Ac3+ 20 DEG C of point) scope keep and the step of carry out soaking；And After heat, the step of scope cooled down untill stopping temperature is cooled down with more than 5 DEG C/sec of average cooling rate.
Hereinafter, it is illustrated according to sequence of steps.
First, preparation meets the hot rolled steel plate of the composition of steel.As long as hot rolling is carried out according to common method, for example, In order to prevent the roughening of austenite grain, heating-up temperature is preferably 1150 DEG C to 1300 DEG C or so.Additionally, it is preferred that finishing temperature is big General control is 850 DEG C to 950 DEG C.
Also, in this invention it is important that it is more than 600 DEG C by the oiler temperature control after hot rolling.Accordingly, in substrate Surface of steel plate formation inner oxide layer, and soft layer is also formed by decarburization, therefore, it is possible to obtain institute in the steel plate after plating Desired inner oxide layer and soft layer.In the case where coiling temperature is less than 600 DEG C, it is impossible to fully generate inner oxide layer And soft layer.Moreover, the intensity of hot rolled steel plate is uprised, cold-rolling property reduction.Coiling temperature is preferably more than 620 DEG C, more preferably More than 640 DEG C.But, if coiling temperature is too high, black oxide skin (black scale) is excessively grown up, it is impossible to pass through pickling And dissolve, therefore its upper limit is preferably less than 750 DEG C.
Then, pickling is carried out and cold rolling to the hot rolled steel plate obtained as described above, makes the mean depth d of inner oxide layer Retain more than 4 μm.Accordingly, not only retain inner oxide layer, and retain soft layer, therefore, easily generation is desired after plating Soft layer.It is known scheme by controlling acid washing conditions and controlling the thickness of inner oxide layer, specifically, according to being made Species, concentration of pickle etc., suitably control temperature, time of pickling etc., so as to ensure desired inside The thickness of oxide layer.
For example as pickle, the inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid can be used.
If in addition, in general, the concentration or temperature of pickle are high or pickling time is long, there is inner oxide layer Dissolve and thinning tendency.If, can not by pickling on the contrary, the concentration or temperature of pickle are low or pickling time is short Fully go except black oxide scale layer.Thus, for example in the case of using hydrochloric acid, it is about 3% to 20% to recommend concentration control, will Temperature control is 60 DEG C to 90 DEG C, is about 35 seconds to 200 seconds by time control.
In addition, pickling slot number is not particularly limited, multiple descaling baths can be used.Moreover, it is also possible to add in pickle Plus the pickling inhibitor such as amine, i.e. inhibitor or acid pickling promotor etc..
After pickling, carried out in the way of the mean depth d for making inner oxide layer retains more than 4 μm cold rolling.It is preferred that it is cold It by cold rolling rate control is in the range of about 20% to 70% that kicker part, which is,.
Then, aoxidized and reduced.
Specifically, first in oxidized zone, with 0.9 to 1.4 air than being aoxidized.Air ratio (air ratio) It is the air capacity and the ratio for the air capacity required in theory for being used to make the burning gases being supplied to burn completely being actually supplied to. Oxygen is in superfluous state if air ratio is higher than 1, and oxygen is in not enough state if air ratio is less than 1.Implement described later It is used as burning gases using CO gases in example.
By in air than the atmosphere as the scope under aoxidized so that decarburization is promoted, therefore, it is possible to shape Into desired soft layer, bendability is improved.Moreover, be able to can suppress to plating in Surface Creation Fe oxide-films Bring the generation of dysgenic complex oxide film etc..If air ratio is less than 0.9, decarburization is insufficient, it is impossible to form abundant Soft layer, therefore bendability reduce.Moreover, the generation of the Fe oxide-films is insufficient, it is impossible to suppress the complex oxide film Deng generation so that plating reduce.The air is more than 0.9 than needing to control, and is preferably controlled to more than 1.0.The opposing party Face, if air than up to more than 1.4, generating Fe oxide-films, can not fully being reduced in follow-up reduction furnace too much, Plating is reduced.The air is less than 1.4 than needing to control, and is preferably controlled to less than 1.2.
In the oxidized zone, air than control it is especially important, condition in addition can be using generally being used Method.For example, the lower limit of the oxidizing temperature is preferably more than 500 DEG C, more preferably more than 750 DEG C.In addition, the oxidation The upper limit of temperature is preferably less than 900 DEG C, more preferably less than 850 DEG C.
Then, in zone of reduction, oxide-film is reduced under a hydrogen atmosphere.In the present invention, provided to obtain In the range of contain bainite and martensite and ferritic hard layer, in (Ac1+ 50 DEG C of point) to (Ac3+ 20 DEG C of point) scope It is interior holding and carry out all heat-treated.If soaking temperature is less than (Ac1+ 50 DEG C of point) then ferrite it is excessive, and if it exceeds (Ac3Point + 20 DEG C), then ferrite is not enough.It is preferred that soaking temperature be (Ac1+ 100 DEG C of point) more than and Ac3Point is following.
In addition, in the present invention, Ac1Point is calculated based on following formula (i).[] represents the content (matter of each element in formula Measure %).The formula exists《Lesley's ferrous materials》Have in (Wan Shan Co., Ltd. issues, and William C.Leslie write, p273) Record.
Ac1(DEG C)=723-10.7 × [Mn] -16.9 × [Ni]+29.1 × [Si]+16.9 × [Cr]+290 × [As]+ 6.38×[W] (i)
In addition, in the present invention, Ac3Point is calculated based on following formula (ii).[] represents the content (matter of each element in formula Measure %).The formula exists《Lesley's ferrous materials》Have in (Wan Shan Co., Ltd. issues, and William C.Leslie write, p273) Record.
Ac3(DEG C)=910-203 × [C]1/2-15.2×[Ni]+44.7×[Si]+104×[V]+31.5×[Mo]+13.1 ×[W]-{30×[Mn]+11×[Cr]+20×[Cu]-700×[P]-400×[Al]-120×[As]-400×[Ti]} (ii)
In the present invention, the retention time under the soaking temperature is preferably more than 10 seconds.If the retention time is shorter than 10 seconds, then reduce insufficient, plating reduction.More preferably more than 30 seconds, more preferably more than 50 seconds.In addition, soaking Retention time during processing is not particularly limited according to the viewpoint, but in view of production efficiency etc., preferably 100 seconds or so with Under, more preferably 80 seconds or so are following.
In the reduction furnace, the control of soaking temperature and the retention time under the soaking temperature are especially important, Condition in addition can use commonly used condition.For example, it is preferable to：The atmosphere of zone of reduction includes hydrogen and nitrogen, and It is scopes of the about 5 volume % to 25 volume % by hydrogen concentration control.Additionally, it is preferred that being -30 DEG C to -60 DEG C by dew point control.
It is then cooled off.Specifically, after soaking, by cool down stop temperature untill scope with more than 5 DEG C/sec put down Equal cooling velocity is cooled down.Hereby it is possible to by the control of ferritic area occupation ratio in prescribed limit.Preferably more than 8 DEG C/sec, More preferably more than 10 DEG C/sec.The upper limit of average cooling rate is not particularly limited, it is contemplated that the control of base steel sheet temperature Easiness and equipment cost processed etc., preferably substantially control is less than 100 DEG C/sec.Preferred average cooling rate is 50 DEG C/sec Hereinafter, more preferably less than 30 DEG C/sec.
In addition, the cooling stops temperature untill not generating ferritic temperature province, being such as preferably cooled to Less than 550 DEG C.The preferred lower limit that cooling stops temperature is, for example, more than 400 DEG C, more preferably more than 430 DEG C, further excellent Elect more than 460 DEG C as.
In this invention it is important that the average cooling rate untill at least described cooling stopping temperature of suitable control, it Cooling means afterwards is not limited to methods described.For example, the situation of plating bath when being heated to galvanizing by dipping after the cooling period Under, it may be lower than the preferred cooling and stop temperature and cool down (for example, referring to the No.26 of table 2 described later).Or, also may be used It is cold to be cooled to the laggard water-filling of set point of temperature.
Then, galvanizing by dipping is carried out according to common method.The method of galvanizing by dipping is not particularly limited, for example, the plating The lower limit of bath temperature is preferably more than 400 DEG C, more preferably more than 440 DEG C.In addition, the upper limit of the plating bath is preferably Less than 500 DEG C, more preferably less than 470 DEG C.The composition of plating bath is not particularly limited, and is bathed using known galvanizing by dipping. In addition, the cooling condition after galvanizing by dipping is also not particularly limited, for example, it is preferable to be by the average cooling rate control untill normal temperature More than about 1 DEG C/sec, more preferably more than 5 DEG C/sec.The upper limit of the average cooling rate is simultaneously not specially provided, but in view of base Easiness and equipment cost of the control of bottom steel billet temperature etc., are preferably controlled to less than about 50 DEG C/sec.The average cooling rate Preferably less than 40 DEG C/sec, more preferably less than 30 DEG C/sec.
Moreover, as needed, Alloying Treatment can also be implemented by common method.Accordingly, alloyed hot-dip plating is obtained Zinc steel plate.The condition of Alloying Treatment is also not particularly limited, for example, carry out after galvanizing by dipping, preferably exist under the described conditions Under 500 DEG C to 600 DEG C or so, particularly preferably under 530 DEG C to 580 DEG C or so, kept for 5 seconds to 30 seconds or so, particularly preferably protected Hold 10 seconds to 25 seconds or so.If less than the scope, alloying becomes insufficient, on the other hand, if it exceeds the model Enclose, then alloying is excessively in progress, coating layer stripping is likely to occur in the punch forming of coated steel sheet.Moreover, ferrite Easily generation.Alloying Treatment is carried out such as can use heating furnace, direct baking or infrared furnace.Heating means Also it is not particularly limited, for example, high-frequency induction heating apparatus (that is, can be utilized using gas heating, sensing heater heating Heating) etc. customary way.
After Alloying Treatment, cooled down according to common method, so as to obtain alloyed hot-dip galvanized steel plate.It is preferred that will Average cooling rate control untill normal temperature is more than about 1 DEG C/sec.
[the second manufacture method (having insulation)]
Second manufacture method involved in the present invention is characterised by turn including the following steps：Temperature more than 500 DEG C The hot-rolled step for batching the hot rolled steel plate for meeting the composition of steel under degree；At a temperature of more than 500 DEG C be incubated 80 minutes with On step；Pickling and cold rolling step are carried out in the way of the mean depth d for making inner oxide layer retains more than 4 μm；In oxygen Change in band, the step of with 0.9 to 1.4 air than being aoxidized；In zone of reduction, in (Ac1+ 50 DEG C of point) to (Ac3Point+20 DEG C) scope keep and the step of carry out soaking；And after soaking, the scope untill cooling is stopped into temperature is with more than 5 DEG C/sec Average cooling rate the step of cooled down.Compared with the first described manufacture method, second manufacture method with it is described First manufacture method only difference is that：The lower limit of coiling temperature after hot rolling is set to more than 500 DEG C；After hot-rolled step Incubation step is set.Therefore, only the difference is illustrated below.On the step consistent with first manufacture method, With reference to first manufacture method.
Set the reasons why incubation step and be as described above：By insulation, it can be kept in oxidable temperature province For a long time, the lower limit for the coiling temperature scope that can obtain desired inner oxide layer and soft layer can be expanded.In addition, also having Have the advantages that to improve the homogeneity of base steel sheet by reducing the top layer of base steel sheet and internal temperature difference.
First, it is more than 500 DEG C by the oiler temperature control after hot rolling in second manufacture method.Described In two manufacture methods, as described later in detail, incubation step is set behind, therefore, it is possible to which coiling temperature is set to less than described the 600 DEG C of the lower limit of coiling temperature in one manufacture method.It is preferred that coiling temperature be more than 540 DEG C, more preferably 570 DEG C with On.In addition, the preferred upper limit of coiling temperature is identical with the first described manufacture method, preferably less than 750 DEG C.
Then, more than 500 DEG C at a temperature of by the hot rolled steel plate obtained as described above be incubated more than 80 minutes.According to This, results in desired inner oxide layer.In order to effectively play the effect of insulation belt, preferably by the hot rolling Steel plate is for example put into the device with thermal insulation and is incubated.As long as the described device used in the present invention is by thermal insulation material Material, which is made, to be just not particularly limited, and as such a material, is preferably used such as ceramic fibre.
In order to effectively play the effect, it is necessary to be incubated more than 80 minutes at a temperature of more than 500 DEG C.It is preferred that temperature Spend for more than 540 DEG C, more preferably more than 560 DEG C.Furthermore it is preferred that time be more than 100 minutes, more preferably 120 minutes More than.Furthermore, it is contemplated that pickling, production efficiency etc., preferably by the probably control of the upper limit of the temperature and time for 700 DEG C with Under, less than 500 minutes.
More than, first and second manufacture method involved in the present invention is illustrated.
For the coated steel sheet of the invention obtained by the manufacture method, can also further it carry out：Various applications With application base treatment, the chemical conversion treatment such as carrying out phosphate treated；And organic coating processing, for example carry out thin Folded etc formation of organic coating of film layer etc..
For the coating used in various applications, known resin, such as epoxy resin, fluororesin, silicon can be used Acrylic resin (silicone acrylic resin), polyurethane resin, acrylic resin, polyester resin, phenol resin, alkyd Resin, melmac etc..From the viewpoint of corrosion resistance, preferably epoxy resin, fluororesin, silicone acrylic resin.Also Curing agent can be used together with the resin.Moreover, coating can also containing known additive, such as colouring pigments, Coupling agent, levelling agent, synergist (intensifier), antioxidant, ultra-violet stabilizer, fire retardant etc..
In the present invention, the form of coating is not particularly limited, and can use the coating of any form, and such as solvent system applies Material, aqueous coating, water-dispersed paint, powder coating, electrophoretic coating etc.., can be with addition, coating process is also not particularly limited Using infusion process, rolling method, spray-on process, curtain coating method, electrophoretic deposition etc..Coating layer, organic coating, chemical conversion treatment The thickness of the clads such as coating, film can suitably be set according to purposes.
The intensity superelevation of the high intensity coated steel sheet of the present invention, and processability (bendability and hole expandability), delayed fracture resistance Excellent, therefore can be used for automobile strength member, impact portions the longeron, collision energy absorbing box such as anterior or rear portion The pillar such as part and center pillar stiffener class, car roof side-beam reinforcer, curb girder, floor component, pin step on the car body component parts such as portion.
The application is based on Japan's patent application filed in 9 days January in 2015 No. 2015-003671 and 2015 8 No. 2015-159212 interests claimed priority of Japan's patent application filed in the moon 11.By application on January 9th, 2015 Japan's patent application the 2015-003671st and August in 2015 11 days filed in Japan patent application 2015- The full content of the specification of No. 159212 is incorporated herein by reference.
Hereinafter, enumerate embodiment and further illustrate the present invention, but the present invention is not limited by following embodiments, certainly also It can be changed to implement in the range of it may conform to addressed purport described later, these are also included in the technology of the present invention In the range of.
Embodiment
To be the heating of plate blank of iron and inevitable impurity with the composition composition and surplus shown in table 1 below to 1250 DEG C, after hot rolling is 2.4mm at 900 DEG C of finishing temperature, batched at the temperatures shown in table 2.
For a part of example No.27~29,38~40,42, it is put into afterwards in ceramic fibre heat-proof device with the institute of table 2 The condition shown is incubated.More than 500 DEG C of soaking time is determined using the thermocouple installed in coil peripheral part.
Then, pickling has been carried out to the hot rolled steel plate obtained as described above under the following conditions, then with 50% it is cold The rate of rolling has carried out cold rolling.Thickness of slab after cold rolling is 1.2mm.
Pickle：10% hydrochloric acid, temperature：82 DEG C, pickling time：As shown in table 2.
Then, in continuous hot-dipping galvanizing production line, (the oxidation, also to be annealed under conditions of shown in table 2 below It is former) and cooling.Here, the temperature of the oxidation furnace set in continuous hot-dipping galvanizing production line is set as 800 DEG C, the hydrogen in reduction furnace Concentration is set to 20 volume %, and surplus is nitrogen and inevitable impurity, and dew point control is -45 DEG C.In addition, shown in table 2 Soaking temperature under retention time be set to 50 seconds.
Then, in addition to following No.26, after the zinc-plated bath for being impregnated in 460 DEG C, with 10 DEG C/sec of average cooling speed Degree is cooled to room temperature, obtains hot-dip galvanized steel sheet (GI) (No.25).On alloyed hot-dip galvanized steel plate (GA), in dipping Implement in the zinc-plated bath after galvanizing by dipping, be heated to 500 DEG C, kept for 20 seconds and carried out at alloying at such a temperature Reason, is then cooled to room temperature (No.1~24,27~42) with 10 DEG C/sec of average cooling rate.
In addition, in No.26, being cooled to cooling described in table 2 and stopping after 250 DEG C of temperature, be heated to 460 DEG C, then It is impregnated in zinc-plated bath, GA steel plates is obtained by method similar to the above.
Following characteristic is have rated for the coated steel sheet i.e. GI or GA obtained as described above.In addition, inner oxide layer Mean depth is not only determined to coated steel sheet as described below, and to pickling, it is cold rolling after base steel sheet similarly Ground is determined, for reference.This is in order to be identified through controlling coiling temperature, the acid washing conditions etc. after hot rolling, in annealing The mean depth of desired inner oxide layer has been obtained in preceding cold-rolled steel sheet.
(1) the mean depth d of the inner oxide layer in coated steel sheet measure
If a width of W of the plate of coated steel sheet, the test piece that size is 50mm × 50mm is acquired from W/4 position, then, is utilized Glow discharge luminescence analysis [GD-OES (Glow Discharge-Optical Emission Spectroscopy)], for O content, Fe contents and Zn contents from plating layer surface are analyzed respectively, and are quantified.Specifically, utilize Hole makes manufactured GD-PROFILER2 types GDA750 GD-OES devices, to the test piece in Ar glow discharge regions Surface carried out high-frequency sputtering, the isolychn of O, Fe, Zn each element for being sputtered in Ar plasmas is continuously carried out Light splitting, so as to determine the distribution of each element amount of the depth direction of base steel sheet.Sputtering condition is as described below, and by measurement region Domain is set to from plating layer surface untill 50 μm of depth.
(sputtering condition)
Pulsed sputter frequency：50Hz
Anode diameter (analysis area)：Diameter 6mm
Discharge power：30W
Ar air pressure：2.5hPa
Analysis result is shown in Fig. 2.As shown in Fig. 2 by the position equal with Fe amounts of the Zn amounts from plating layer surface It is set to the interface between coating layer and base steel sheet.In addition, by from plating layer surface 40 μm to 50 μm of depth each measure position The average value of the O amounts at the place of putting is set to the O amount average values inside test piece, and by than its high 0.02% scope, i.e. O amounts >=(test piece Internal O amounts average value+0.02%) inner oxide layer is defined as, its depth capacity is set to internal oxidation layer depth.Utilize 3 Individual test piece implements same experiment, is averaged the mean depth d for being set to inner oxide layer.
(2) pickling, it is cold rolling after internal oxidation layer depth measure (reference)
Except using pickling, it is cold rolling after base steel sheet this point in addition to, calculated by the mode same with (1) The mean depth of inner oxide layer.
(3) the mean depth D of soft layer measure
Expose the i.e. W/4 positions in section perpendicular to the wide W directions of plate of coated steel sheet, collection size is 20mm × 20mm's After test piece, it is embedded in resin, and from the interface between coating layer and base steel sheet, towards in the thickness of slab t of base steel sheet Portion determines Vickers hardness.Using Vickers, it is determined in the case where load is 3gf.Specifically, as shown in figure 3, certainly The thickness of slab internal depth that the interface of coating layer 1 and base steel sheet 2 is risen is 10 μm of the beginning that locates, towards thickness of slab inside every 5 μm of spacing has carried out the measure of Vickers hardness, until the position of 100 μm of depth.Interval between measuring point, i.e. in figure 3 × with × the distance between minimum also have more than 15 μm.Vickers hardness is determined with n=1 number in each depth location, adjusted The hardness distribution of thickness of slab internal direction is looked into.Further, using Vickers, base steel sheet is determined in the case where load is 1kgf T/4 positions Vickers hardness (n=1).By compared with the Vickers hardness at the t/4 positions of base steel sheet Vickers hardness be 90% with Under region be set to soft layer, and calculate its depth.10 positions in same test piece implement same experiment, by it Averagely it is set to the mean depth D of soft layer.
(4) assay method of the tissue point rate of coated steel sheet
Expose the section W/4 positions perpendicular to the wide W directions of plate of coated steel sheet, and the section is polished, and then Carry out after electrobrightening, carry out nitric acid ethanol corrosion, seen with SEM (Scanning Electron Microscope) Examine.Observation position is the t/4 positions when thickness of slab of base steel sheet to be set to t, and observation multiplying power is 2000 times, and viewing area is 40 μm ×40μm.Graphical analysis has been carried out to the metal structure photograph shot with SEM, martensite and bainite (not area are determined respectively Both point) and ferritic area occupation ratio.In table 3, α=ferrite, (B+M)=(bainite and martensite).In addition, in table 3, The Line Integral rate of the tissue of " other " is to subtract martensite and bainite and ferritic each area occupation ratio from 100 area % and count Calculate.Arbitrarily observed with 3 visuals field and calculated average value.
(5) assay method of tension test
Gathered in the way of the direction of the rolling direction perpendicular to coated steel sheet and the long side direction of test piece is parallel to each other JIS13 B tensile test specimens, determine the tensile strength (TS) in C directions, yield stress (YS) according to JIS Z2241 and prolong Stretch rate (EL).Yield ratio YR (YS/TS) is calculated according to TS and YS.
In the present embodiment, more than 980MPa tensile strength TS is evaluated as high intensity (qualified).
In addition, having calculated TS × EL according to the tensile strength and extensibility meter obtained as described above.In the present embodiment, will TS × EL is that more than 14000 steel plate is evaluated as (qualified) excellent in balance of intensity and ductility.
(6) bending machining is tested
Prepare so that the side that the long side direction perpendicular to the direction of the rolling direction of coated steel sheet and test piece is parallel to each other The test piece for 20mm × 70mm that formula is cut out from coated steel sheet, has carried out 90 ° of V-types in the way of making bending crest line along long side direction Bend test.Experiment is implemented by suitably changing radius of curvature R, fracture can be produced not allowing by having obtained in test piece The minimum bending radius Rmin of bending machining is carried out under state.
Thickness of slab t based on Rmin divided by base steel sheet and gained Rmin/t, have rated curved respectively by each tensile strength TS Qu Xing.Detailed content is as described below.In addition, being unsatisfactory for qualified more than benchmark 980MPa test piece for TS, bending is not evaluated Property (being designated as "-" in table 3).
TS be 980MPa less than 1080MPa in the case of, using Rmin/t ＜ 1.5 as qualified.
TS be 1080MPa less than 1180MPa in the case of, using Rmin/t ＜ 2.5 as qualified.
In the case where TS is more than 1180MPa, using Rmin/t ＜ 3.2 as qualified.
(7) delayed fracture resistance characteristics are tested
Expose the i.e. W/4 positions in section perpendicular to the wide W directions of plate of coated steel sheet, cut out 150mm (W) × 30mm (L) test piece, is carried out after U-bend processing with minimum bending radius, is fastened with screw, and the outside of test piece is processed to U-bend Surface is applied with 1000MPa tensile stress.Strain gauge is attached to U-bend and processes the outside of test piece, and strain is scaled Tensile stress determines tensile stress.Then, masking U-bend processes the edge part of test piece, electrochemically carries out It is flushed with hydrogen.Be flushed with hydrogen is that test piece is immersed in into 0.1M-H2SO4(pH=3) and in 0.01M-KSCN mixed solution, in room temperature and 100 μ A/mm2Constant current under conditions of carry out.
The result for being flushed with hydrogen experiment, by 24 hours it is unbroken be evaluated as qualified, i.e., delayed fracture resistance characteristics are excellent.
(8) hole expansion test
Implement hole expansion test according to Nippon Steel alliance specification JFST1001, determine λ.Specifically, in coated steel sheet On rushed a diameter of 10mm hole, then, around fixed in the state of by 60 ° of circular cone drift press-in hole, determine crackle Produce the diameter in critical hole.Critical hole expansibility λ (%) is obtained according to following formula, it is qualified to be evaluated as when λ is more than 20%, i.e., Hole expandability is excellent.
Critical hole expansibility λ (%)={ (Df-D0)/D0 } × 100
In formula, Df is the diameter (mm) that crackle produces critical hole, and D0 is initial hole diameter (mm).
(9) plating appearance
The outward appearance of coated steel sheet has been observed by the naked eye, plating is have rated based on the non-plating of generation is whether there is.
These results are shown in table 2 and table 3.
Can as follows it be investigated according to table.
First, No.1~12,16,18,21,25,26,27,30~42 be meet the present invention important document example, intensity, Processability [equilibrium (TS × EL), bendability and the hole expandability (λ) of intensity and ductility], delayed fracture resistance characteristics, plating are good It is good.The particularly mean depth d of inner oxide layer and the mean depth D of soft layer meet D ＞ 2d (i.e., in table 2 " D/2d " value More than relation 1) No.1 (D/2d=1.21) compared with the No.21 (D/2d=0.92) for being unsatisfactory for the relation, bendability Improve.
In contrast, No.13 is the steel grade M for the table 1 for having used C amounts many example, bendability, λ and delayed fracture resistance Characteristic is reduced.
No.14 is the steel grade N for the table 1 for having used Si amounts few example, inner oxide layer nonfully, bendability, λ, Intensity and the equilibrium of ductility and delayed fracture resistance characteristics reduction.
Coiling temperature when No.15 is the steel grade A for the table 1 for having used the important document of the composition of steel satisfaction present invention but hot rolling is low Example, pickling, it is cold rolling after inner oxide layer mean depth it is shallow therefore the mean depth d of inner oxide layer after plating, soft The mean depth D of matter layer also shoals.As a result, bendability, λ, delayed fracture resistance characteristics and plating reduction.
No.17 is the steel grade A but the high example of soaking temperature for the table 1 for having used the important document of the composition of steel satisfaction present invention, complete It is complete not generate ferrite, therefore the balanced reduction of intensity and ductility.
No.19 is the steel grade A but the low example of soaking temperature, iron for the table 1 for having used the important document of the composition of steel satisfaction present invention Ferritic is excessively generated and the total amount of (B+M) also tails off, and fails to obtain desired hard layer.Therefore, TS step-downs, λ is also reduced.
No.20 be used composition of steel meet the present invention important document table 1 steel grade A but oxidation furnace in air than low Example, ferroelectric oxide film nonfully, plating reduction.Moreover, soft layer also nonfully, therefore, bendability, λ, resistance to prolong Slow fracture characteristics are also reduced.
No.22 be used composition of steel meet the present invention important document table 1 steel grade A but coiling temperature during hot rolling it is low and Air in oxidation furnace than low example, pickling, it is cold rolling after inner oxide layer mean depth it is shallow, therefore the inside after plating The mean depth d of oxide layer, the mean depth D of soft layer also shoal.As a result, λ, bendability, delayed fracture resistance characteristics and plating The property covered is reduced.
Coiling temperature when No.23 is the steel grade A for the table 1 for having used the important document of the composition of steel satisfaction present invention but hot rolling is low Example, pickling, it is cold rolling after inner oxide layer mean depth it is shallow, therefore the mean depth d of the inner oxide layer after plating Shoal.As a result, λ, delayed fracture resistance characteristics and plating reduction.
No.24 is the average cooling rate after the steel grade A for the table 1 for having used the important document of the composition of steel satisfaction present invention but soaking Slow example, ferrite is excessively generated in cooling procedure and the total amount of (B+M) also tails off, and fails to obtain desired hard Layer.Therefore, λ, bendability reduction.
Coiling temperature when No.28 is the steel grade A for the table 1 for having used the important document of the composition of steel satisfaction present invention but hot rolling is low Example, pickling, it is cold rolling after inner oxide layer mean depth it is shallow therefore the mean depth d of inner oxide layer after plating, soft The mean depth D of matter layer also shoals.As a result, bendability, λ, delayed fracture resistance characteristics and plating reduction.
No.29 is the steel grade A but the insufficient example of soaking time for the table 1 for having used the important document of the composition of steel satisfaction present invention Son, pickling, it is cold rolling after inner oxide layer mean depth it is shallow therefore the mean depth d of inner oxide layer after plating, soft The mean depth D of layer also shoals.As a result, bendability, λ, delayed fracture resistance characteristics and plating reduction.
Symbol description
1 coating layer
2 base steel sheets
3 inner oxide layers
4 soft layers
5 hard layers

Claims (6)

1. a kind of high intensity coated steel sheet, has dip galvanized or alloyed hot-dip zinc-coated layer on the surface of base steel sheet, its It is characterised by,
(1) base steel sheet contains C in terms of quality %：0.05% to 0.25%, Si：0.25% to 3%, Mn：1.5% to 4%th, P：More than 0% and less than 0.1%, S：More than 0% and less than 0.05%, Al：0.005% to 1%, N：More than 0% and Less than 0.01%, surplus is iron and inevitable impurity,
(2) from the interface between the base steel sheet and the coating layer, basad steel plate side is included successively：
Inner oxide layer, comprising selected from the oxide by least one of Si and the Mn group constituted；
Soft layer, comprising the inner oxide layer, also, when the thickness of slab of the base steel sheet is set into t, with the substrate Less than 90% Vickers hardness of the Vickers hardness at the t/4 positions of steel plate；And
Hard layer, comprising 60 area % less than 95 area % martensite and bainite, more than 5 area % and 40 faces Product below % polygonal ferrite, wherein,
The mean depth D of the soft layer is more than 20 μm,
The mean depth d of the inner oxide layer be 4 μm less than the D,
The tensile strength of the high intensity coated steel sheet is more than 980MPa.
2. high intensity coated steel sheet according to claim 1, it is characterised in that the base steel sheet is also contained in terms of quality % There is at least one in following (a)~(c)：
(a) from by Cr：More than 0% and less than 1%, Mo：More than 0% and less than 1% and B：More than 0% and less than 0.01% institute's structure Into group at least one that selects；
(b) from by Ti：More than 0% and less than 0.2%, Nb：More than 0% and less than 0.2% and V：More than 0% and less than 0.2% At least one selected in the group constituted；
(c) from by Cu：More than 0% and less than 1% and Ni：At least one selected in the group constituted more than 0% and less than 1% Kind.
3. high intensity coated steel sheet according to claim 1, it is characterised in that
The mean depth d of the inner oxide layer and mean depth D of the soft layer meets D ＞ 2d relation.
4. high intensity coated steel sheet according to claim 2, it is characterised in that
The mean depth d of the inner oxide layer and mean depth D of the soft layer meets D ＞ 2d relation.
5. a kind of manufacture method of high intensity coated steel sheet, it is characterised in that for any one of manufacturing claims 1 to 4 institute The high intensity coated steel sheet stated, the manufacture method includes successively：
The hot-rolled step of the coiler plate of the composition of steel of the base steel sheet will be met at a temperature of more than 600 DEG C；
Pickling and cold rolling step are carried out in the way of the mean depth d for making inner oxide layer retains more than 4 μm；
In oxidized zone, the step of with 0.9 to 1.4 air than being aoxidized；
In zone of reduction, in (Ac1+ 50 DEG C of point) to (Ac3+ 20 DEG C of point) scope keep and the step of carry out soaking；And
After soaking, the step of scope cooled down untill stopping temperature is cooled down with more than 5 DEG C/sec of average cooling rate.
6. a kind of manufacture method of high intensity coated steel sheet, it is characterised in that for any one of manufacturing claims 1 to 4 institute The high intensity coated steel sheet stated, the manufacture method includes successively：
The hot-rolled step of the coiler plate of the composition of steel of the base steel sheet will be met at a temperature of more than 500 DEG C；
The step of being incubated more than 80 minutes at a temperature of more than 500 DEG C；
Pickling and cold rolling step are carried out in the way of the mean depth d for making inner oxide layer retains more than 4 μm；
In oxidized zone, the step of with 0.9 to 1.4 air than being aoxidized；
In zone of reduction, in (Ac1+ 50 DEG C of point) to (Ac3+ 20 DEG C of point) scope keep and the step of carry out soaking；And
After soaking, the step of scope cooled down untill stopping temperature is cooled down with more than 5 DEG C/sec of average cooling rate.
CN201680005029.6A 2015-01-09 2016-01-05 Plating, processability and the excellent high-strength steel sheet of delayed fracture resistance characteristics and its manufacture method Pending CN107109574A (en)

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MX2019009701A (en) 2017-02-20 2019-10-02 Nippon Steel Corp High strength steel sheet.
US11732321B2 (en) 2019-03-29 2023-08-22 Nippon Steel Corporation Steel sheet and method of producing same
KR102231344B1 (en) * 2019-05-17 2021-03-24 주식회사 포스코 Ultra-high strength steel sheet having excellent hole-expandability and ductility, and method for manufacturing thereof
WO2021167332A1 (en) * 2020-02-18 2021-08-26 주식회사 포스코 Steel sheet with excellent surface quality, and manufacturing method therefor
WO2021176249A1 (en) * 2020-03-02 2021-09-10 Arcelormittal High strength cold rolled and galvannealed steel sheet and manufacturing process thereof
EP4163405A4 (en) 2020-06-08 2024-06-26 Nippon Steel Corporation Steel sheet and manufacturing method therefor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102482753A (en) * 2009-08-31 2012-05-30 新日本制铁株式会社 High-strength hot-dip galvanized steel sheet and process for producing same
CN103842542A (en) * 2011-09-30 2014-06-04 新日铁住金株式会社 High-strength hot-dip galvanized steel plate having excellent impact resistance and method for producing same, and high-strength alloyed hot-dip galvanized steel sheet and method for producing same

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4781836B2 (en) * 2006-02-08 2011-09-28 新日本製鐵株式会社 Ultra-high strength steel sheet excellent in hydrogen embrittlement resistance, its manufacturing method, manufacturing method of ultra-high strength hot-dip galvanized steel sheet, and manufacturing method of ultra-high-strength galvannealed steel sheet
JP5636727B2 (en) * 2010-04-27 2014-12-10 新日鐵住金株式会社 Hot-dip galvanized steel sheet and manufacturing method thereof
JP6023612B2 (en) * 2012-04-20 2016-11-09 株式会社神戸製鋼所 Manufacturing method of high-strength cold-rolled steel sheets with excellent chemical conversion properties
JP2015034334A (en) * 2013-07-12 2015-02-19 株式会社神戸製鋼所 High-strength plated steel sheet excellent in platability, processability and delayed fracture resistance characteristics and production method thereof
JP2015193907A (en) * 2014-03-28 2015-11-05 株式会社神戸製鋼所 Alloyed high-strength hot-dip galvanized steel sheet having excellent workability and delayed fracture resistance, and method for producing the same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102482753A (en) * 2009-08-31 2012-05-30 新日本制铁株式会社 High-strength hot-dip galvanized steel sheet and process for producing same
CN103842542A (en) * 2011-09-30 2014-06-04 新日铁住金株式会社 High-strength hot-dip galvanized steel plate having excellent impact resistance and method for producing same, and high-strength alloyed hot-dip galvanized steel sheet and method for producing same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112840047A (en) * 2019-02-06 2021-05-25 日本制铁株式会社 Hot-dip galvanized steel sheet and method for producing same
CN113789482A (en) * 2021-09-01 2021-12-14 安徽金亿新材料股份有限公司 High-energy-absorption Chang' e steel, valve seat ring and preparation method thereof

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