CN101264681B - Hot-dip galvannealed steel sheet, steel sheet treated by hot-dip galvannealed layer diffusion and a method of producing the same - Google Patents
Hot-dip galvannealed steel sheet, steel sheet treated by hot-dip galvannealed layer diffusion and a method of producing the same Download PDFInfo
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Abstract
The present invention provides: a high-strength high-ductility hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet excellent in ductility, which improves non-plating defects and plating adhesion after severe deformation, and a method of producing the same; a high-strength and high-ductility hot-dip galvanized steel sheet having high fatigue resistance and corrosion resistance; a high-strength hot-dip galvanized steel sheet and hot-dip galvannealed steel sheet having superior appearance and workability, which suppresses the generation of non-plating defects, and a method of producing the same; and a high-strength hot-dip galvannealed steel sheet and a high-strength hot-dip galvanized steel sheet, which suppress non-plating defects and surface defects and have both corrosion resistance, in particular corrosion resistance in an environment containing chlorine ion, and high ductility, and a method of producing the same.
Description
The application submitted on June 6th, 2002, and denomination of invention is divided an application for Chinese patent application No.02811523.6 (the international application no PCT/JP02/05627's) of " having the high-strength hot-dip galvanized sheet metal of high binding force of cladding material behind fatigue resistance, corrosion resistance, ductility and the severe deformation and sheet metal and the manufacture method thereof of dip galvanized DIFFUSION TREATMENT ".
Technical field
Invention relates to the galvanizing by dipping sheet metal of a kind of high strength, high ductibility and dip galvanized through the sheet metal of DIFFUSION TREATMENT, this steel plate has excellent fatigue resistance and corrosion resistance, be suitable for construction material, household electrical appliance and automobile, and this steel plate in the chloride ion-containing environment corrosion resistance and excellent workability and relate to and the manufacture method of this steel plate.
Technical background
The galvanizing by dipping technology is used for sheet metal and is intended to prevent corrosion, and galvanizing by dipping sheet metal and dip galvanized DIFFUSION TREATMENT sheet metal are widely used in building materials, household electrical appliances, automobile etc.Sendzimir (Sendzmir) galvannealing is followed successively by at tinuous production as the step that a kind of manufacture method comprises: oil removing is cleared up, heats sheet metal in non-oxidizing atmosphere, is being contained H
2And N
2Reducing atmosphere in sheet metal annealing, be cooled near the coating bath temperature temperature, immerse in the fused zinc groove, and will it cooling or through reheat make it alloying formation Fe-Zn alloy after with its cooling.The Sendzimir processing method is widely used in sheet metal and processes.
As for annealing before plating, usually use full reduction furnace, wherein annealing is right after after the oil removing cleaning, heats the sheet metal operation namely in containing H without nonoxidizing atmosphere
2And N
2Reducing atmosphere in carry out.In addition, also adopt the flux growth metrhod that comprises following operation: sheet metal is carried out oil removing and pickling; Then use ammonium chloride or similar substance to carry out fiux technique; Sheet metal is immersed in the coating bath; Then cool off sheet metal.
At a kind of coating bath for above-mentioned those processing methods, add a small amount of Al and remove oxygen in the fused zinc.In Sendzimir coating process, zinc-plated liquation approximately contains 0.1% (quality) Al.It is reported, because Al is stronger to the affinity comparison Fe-Zn of Fe in the plating bath, therefore, when steel immersed plating bath, producing one deck Fe-Al alloy-layer also was rich aluminium lamination, thereby has suppressed the Fe-Zn reaction.Because the existence of rich aluminium lamination, cause Al content in the gained coating generally to be higher than Al content in the plating bath.
Recently, consider and improve durability and be intended to improve automobile fuel efficiency and alleviate body quality, the demand of the high strength galvanized sheet metal of excellent processability is increased increasingly.Add Si in the steel as a kind of Enhancement Method of economy, the high ductibility high-strength steel sheet often contains the Si that is not less than 1% (quality) in practice.In addition, high strength steel also contains various alloy, and therefore so that, consider strict restriction heat treatment method to guarantee high-intensity angle from the control microscopic structure.
Moreover, from the angle of plating operation, if Si content surpasses 0.3% (quality) in the steel, use in routine in the situation of the Sendzimir coating process that contains the Al plating bath, the obvious variation of the wellability of coating, and produce the plating leakage defective, cause degraded appearance.It is said, above-mentioned shortcoming be since in the reduced anneal process on the surface of thin steel sheet the various oxides of Si concentrate and the various oxides of Si and zinc wellability poor due to.
In the situation that high-strength steel sheet, that explains above the various elements that add all resemble enriches like that, so the alloying heat treatment of carrying out behind the plating carries out under higher temperature usually, and the time is longer than mild steel.This is one of obstacle that guarantees the good material quality.
In addition, consider from the viewpoint of improving the structural member durability, except corrosion resistance, fatigue resistance also is important.In other words, a kind of high-strength steel sheet with good plating production capacity, good fatigue resistance and good corrosion resistance of research and development is very important.
As a kind of measure that addresses these problems, the flat 3-28359 peace of Japanese Patent Application Publication specification 3-64437 discloses a kind of method of improving coating performance by the extraordinary coating of plating.Yet the problem of this method is that the method need to be installed a kind of new plater in the annealing furnace front of galvanizing by dipping production line, perhaps set up the plating pre-treatment at the electroplating activity streamline, and this will improve production cost.In addition, considering fatigue resistance and corrosion resistance, is effectively although recently disclose interpolation copper, has no the record of itself and corrosion resistance compatibility at all.
Moreover the Si scale defective that produces during hot rolling causes the Deposit appearance variation in subsequent handling.It is necessary that Si content in the minimizing steel suppresses Si scale defective, but at the retained austenite sheet metal or belong in the typical high ductibility type steel-sheet two-phase steel-sheet situation, Si is a kind of to improving the very effective interpolation element of balance between intensity and the ductility.In order to overcome this problem, someone discloses the method that a kind of condition by control annealing atmosphere and so on is controlled the oxide form that produces.Yet this method requires special installation, thereby needs to increase new equipment investment.
Darker one deck, in order to alleviate quality and sheet metal by the reduction lamella thickness again and again during attenuate when adopting high-strength steel sheet, often even need galvanizing by dipping sheet metal or dip galvanized DIFFUSION TREATMENT sheet metal can further improve corrosion resistance.For instance, dispensing rock salt is a kind of harsh environment as the environment of snow melting agent, because rock salt contains relatively large Cl
-Ion.If coating is just not enough in the corrosion resistance of the part generation local shedding of the work of taking the weight or coating itself, then needs the matrix material of excellent corrosion resistance, and need to form the coating of excellent corrosion resistance.
So far also do not develop and a kind ofly allow to alleviate quality with thickness and consider the problem of intensity, relevant Si and the sheet metal that the improvement corrosion resistance is made comprehensively.
Darker one deck, when being intended to improve high-strength steel sheet plating production capacity, Japanese Patent Application Publication specification H5-230608 discloses the galvanizing by dipping sheet metal that a kind of Al-Mn-Fe of having is coating.Yet, although production capacity has been considered in this patent application, and reckon without the binding force of cladding material of high-strength high-tractility material when taking the weight work.
In addition, take the absorbability that improves impact energy as purpose, Japanese Patent Application Publication specification H11-189830 discloses a kind of sheet metal, and it has average grain size and is not more than 10 μ m, comprises ferritic principal phase; Average grain size is not more than 5 μ m, comprises 3～50% (volume) austenites or the martensitic second-phase of 3～30% (volumes); And can select to contain bainite.But this invention does not take into account the coating wellability, and does not provide and allow to subtract corrosion resistance thick and when following intensity to improve.
Summary of the invention
The invention provides a kind of can solve above-mentioned variety of issue, outward appearance and machinability all excellent, can improve plating leakage defective and the adhesion of coating behind strong deformation and the zinc-plated DIFFUSION TREATMENT sheet metal of high strength and the manufacture method thereof of ductility excellence, and the present invention also provides high-strength high-tractility zinc coat DIFFUSION TREATMENT sheet metal and the manufacture method thereof of a kind of high-strength high-tractility galvanizing by dipping sheet metal and a kind of corrosion resistance and fatigue resistance excellence.
In addition, the purpose of this invention is to provide a kind of high-strength hot-dip galvanized sheet metal and a kind of high-strength hot-dip galvanized layer DIFFUSION TREATMENT sheet metal and manufacture method thereof that can address the above problem, suppress plating leakage defective and blemish and in the environment that especially contains chlorion, have simultaneously corrosion resistance and high ductibility.
Result as various tests, all inventors of the present invention have found that, might produce a kind of even still have excellent processability when regulating heat-treat condition, and improve simultaneously the zinc coat DIFFUSION TREATMENT sheet metal of corrosion resistance and the fatigue resistance of high-strength steel sheet by the microscopic structure of interface between adjusting coating and basic unit's (steel layer) (below be called " coating/basic unit interface ").In addition, they also find, make coating contain an amount of element-specific, can make that the wellability of fused zinc is improved on the high-strength steel sheet.They and then discovery, the Al concentration that reduces in the coating can make above-mentioned each effect strengthen; And even in the situation of the high-strength steel sheet that contains quite a large amount of alloying elements, by Si content X% (quality), Mn content Y% (quality) in the control steel and Al content Z% (quality) and in addition the Al content A% (quality) in the coating and Mn content B% (quality) to satisfy following formula 1:
3-(X+Y/10+Z/3)-12.5×(A-B)≥0 ...1
Also can obtain very good coating.
And they also find, even through optionally adding an amount of alloying element and removing condition of heat treatment by regulating the steel-sheet microscopic structure, still can produce the sheet metal with high ductibility.
Result as various tests, all inventors of the present invention have found that, in the situation that high-strength steel sheet, be combined by each component that makes coating contain an amount of element-specific and to make it in sheet metal, just can improve the wellability in the galvanizing by dipping process, accelerate the alloying reaction in the alloy layer.This effect mainly realizes by the Al concentration in the control coating and the Mn concentration in the steel.
They find, by Al content Z% (quality) in Mn content X% (quality) and Si content Y% (quality) and the coating in the control steel, to satisfy following formula 2:
0.6-(X/18+Y+2)≥0 ...2
Can obtain a kind of very good coating.
Result as various tests, all inventors of the present invention have found that, in the situation that high-strength steel sheet, be combined through each composition that makes coating contain an amount of element-specific and to make it in sheet metal, can improve the wellability in galvanizing by dipping and the dip galvanized DIFFUSION TREATMENT process, accelerate the alloying reaction in the alloy layer, and can improve ductility and corrosion resistance.This effect can be mainly concentration by Mo in the concentration of Al and Mo in the control coating and the steel realize.
In other words, they find, make and contain 0.001% (quality) in the coating to 4% (quality) Al, and the Al content A% (quality) in the control coating and the Mo content C% (quality) in Mo content B% (quality) and the steel, make it to satisfy following formula 3:
100≥(A/3+B/6)/(C/6)≥0.01 ...3
Can obtain a kind of plating sheet metal of dip galvanized DIFFUSION TREATMENT of high-strength high-tractility.
On the basis of above-mentioned discovery, the present invention is accomplished, and main points of the present invention are as follows:
(1) has high-strength high-tractility galvanizing by dipping sheet metal and the dip galvanized DIFFUSION TREATMENT sheet metal of high resistance fatigability and corrosion resistance, the sheet metal of this galvanizing by dipping sheet metal or dip galvanized DIFFUSION TREATMENT has one deck coating in the substrate surface that is made of sheet metal, it is characterized in that, the depth capacity of the grain boundary oxide layer that forms at the interface between coating and basic unit is not more than 0.5 μ m.
(2) have high-strength high-tractility galvanizing by dipping sheet metal and the dip galvanized DIFFUSION TREATMENT sheet metal of high resistance fatigability and corrosion resistance, this galvanizing by dipping sheet metal or dip galvanized DIFFUSION TREATMENT sheet metal have one deck coating in the substrate surface that is made of sheet metal, it is characterized in that, the depth capacity of the grain boundary oxide layer at the interface between coating and basic unit is not more than 1 μ m, and the average grain size of principal phase is not more than 20 μ m in basic unit's microscopic structure simultaneously.
(3) above (1) or (2) described high-strength high-tractility galvanizing by dipping sheet metal and dip galvanized DIFFUSION TREATMENT sheet metal with high resistance fatigability and corrosion resistance, this galvanizing by dipping sheet metal or dip galvanized DIFFUSION TREATMENT sheet metal have one deck coating in the substrate surface that is comprised of sheet metal, it is characterized in that, the average grain size of principal phase is not more than 0.1 divided by the value of the grain boundary oxide layer depth capacity gained that forms at the interface between coating and the basic unit in basic unit's microscopic structure.
(4) (1) any one describedly has the high-strength high-tractility galvanizing by dipping sheet metal of high resistance fatigability and highly corrosion resistant and a sheet metal of dip galvanized DIFFUSION TREATMENT in (3), it is characterized in that, in the sheet metal microscopic structure by volume, contain 50% to 97% ferrite or ferrite and bainite as principal phase, and contain a kind of in the martensite that accounts for cumulative volume 3% to 50% and the austenite or two kinds as second-phase.
(5) (1) in (4) any one described high-strength high-tractility galvanizing by dipping sheet metal and dip galvanized DIFFUSION TREATMENT sheet metal with high resistance fatigability and corrosion resistance, it is characterized in that, in mass, coating contains:
Al 0.001～0.5%, and
Mn 0.001～2％，
Surplus is zinc and inevitable impurity; And Si content: X (quality %) in the sheet metal, Al content: A (quality %) and Mn content: B (quality %) satisfy following formula 1 in Mn content: Y (quality %) and Al content: Z (quality %) and the coating:
3-(X+Y/10+Z/3)-12.5×(A-B)≥0 ...1。
The high-strength high-tractility dip galvanized DIFFUSION TREATMENT sheet metal with high antifatigue and highly corrosion resistant described in (6) (5) is characterized in that, containing the Fe amount in the coating is 5% (quality)～20% (quality).
(7) the high-strength hot-dip galvanized sheet metal of high binding force of cladding material and ductility behind a kind of severe deformation, described galvanizing by dipping sheet metal has one deck coating, and in mass, coating contains,
Al:0.001～0.5%, and
Mn：0.001～2％，
Surplus is zinc and inevitable impurity, and in mass, surface of thin steel sheet is comprised of following compositions,
C：0.0001～0.3％，
Si：0.01～2.5％，
Mn：0.01～3％，
Al:0.001～4%, and
Surplus is iron and inevitable impurity, it is characterized in that, Si content in the sheet metal: X (quality %), Al content: A (quality %) and Mn content: B (quality %) satisfy following formula 1 in Mn content: Y (quality %) and Al content: Z (quality %) and the coating; And in the sheet metal microscopic structure by volume, have and comprise 70% to 97% ferritic principal phase, and the average grain size of principal phase is not more than 20 μ m, by volume, contain 3% to 30% austenite and/or the average grain size of martensitic second-phase and second-phase and be not more than 10 μ m:
3-(X+Y/10+Z/3)-12.5×(A-B)≥0 ...1。
The sheet metal with high-strength hot-dip galvanized layer DIFFUSION TREATMENT of high binding force of cladding material and ductility behind the severe deformation described in (8) (7) is characterized in that, also contains 5% (quality) in the coating to the Fe of 20% (quality).
(9) (7) or (8) described in have high binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility and a sheet metal of dip galvanized DIFFUSION TREATMENT behind the severe deformation, it is characterized in that, the austenite of formation sheet metal second-phase and/or martensitic average grain size are 0.01 to 0.7 times of ferrite average grain size.
(10) (7) any one describedly has binding force of cladding material and the high-strength hot-dip galvanized sheet metal of extension and a sheet metal of dip galvanized DIFFUSION TREATMENT behind the severe deformation in (9), it is characterized in that, the steel-sheet microscopic structure has and comprises 50% (volume) to the average grain size of the ferritic principal phase of 95% (volume) and principal phase and be not more than 20 μ m, and comprise 3% (volume) to the average grain size of 30% (volume) austenite and/or martensitic second-phase and second-phase and be not more than 10 μ m, also contain simultaneously 2% (volume) to the bainite of 47% (volume).
(11) (7) any one describedly has high binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility and a sheet metal of dip galvanized DIFFUSION TREATMENT behind the severe deformation in (10), it is characterized in that, also contain 0.001% (quality) in the described steel to the Mo of 5% (quality).
(12) (7) any one describedly has high binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility and a sheet metal of dip galvanized DIFFUSION TREATMENT behind the severe deformation in (11), it is characterized in that, also contain 0.0001% (quality) in the described steel to the S of the P and 0.0001% (quality) to 0.01% (quality) of 0.1% (quality).
(13) (7) any one describedly has the high-strength hot-dip galvanized sheet metal of high antifatigue and highly corrosion resistant and a sheet metal of dip galvanized DIFFUSION TREATMENT in (12), it is characterized in that, Si content is that 0.001% (quality) is to 2.5% (quality) in the steel.
(14) a kind of sheet metal with high-strength hot-dip galvanized layer DIFFUSION TREATMENT of excellent appearance and machinability, the sheet metal of described dip galvanized DIFFUSION TREATMENT has one deck coating, and in mass, this coating contains,
Mn：0.001％～3％，
Al：0.001％～4％，
Mo:0.0001%～1%, and
Fe：5％～20％，
Surplus is zinc and inevitable impurity, in mass, contains on the surface of thin steel sheet
C：0.0001％～0.3％
Si:0.001%～be lower than 0.1%
Mn：0.01％～3％
Al：0.001％～4％
Mo：0.001％～1％
P：0.0001％～0.3％
S:0.0001%～0.1% and
Surplus is iron and inevitable impurity, it is characterized in that the Mn content in the steel: X (quality %) and Si content: Y (quality %) satisfy following formula 2 with the Al content in the coating: Z (quality %):
0.6-(X/18+Y+Z)≥0 ...2。
(15) a kind of high-strength hot-dip galvanized sheet metal with excellent appearance and machinability, described galvanizing by dipping sheet metal has one deck coating, and in mass, this coating contains,
Mn 0.001％～3％，
Al 0.001％～4％，
Mo 0.0001%～1%, and
Fe is less than 5%,
Surplus is zinc and inevitable impurity, in mass, contains on the surface of thin steel sheet
C：0.0001％～0.3％，
Si:0.001% is to less than 0.1%,
Mn：0.01％～3％，
Al：0.001％～4％，
Mo：0.001％～1％，
P：0.0001％～0.3％，
S:0.0001%～0.1%, and
Surplus is Fe and inevitable impurity, it is characterized in that, the Al content in the Mn content in the steel: X (quality %) and Si content: Y (quality %) and the coating: Z (quality %) satisfies following formula 2:
0.6-(X/18+Y+Z)≥0 2。
(16) a kind of sheet metal of dip galvanized DIFFUSION TREATMENT of the high-strength high-tractility with highly corrosion resistant, the sheet metal of described dip galvanized DIFFUSION TREATMENT has one deck coating, and in mass, this coating contains,
Al 0.001～4%, and
Fe 5％～20％，
Surplus is zinc and inevitable impurity, in mass, contains on the surface of thin steel sheet
C：0.0001～0.3％，
Si:0.001～less than 0.1%,
Mn：0.001～3％，
Al：0.001～4％，
Mo：0.001～1％，
P：0.001～0.3％，
S:0.0001～0.1%, and
Surplus is Fe and inevitable impurity, it is characterized in that, in the coating in Al content A (quality %) and Mo content B (quality %) and the steel Mo content C (quality %) satisfy following formula 3; And the microscopic structure of steel comprises that by accounting for 50% to 97% (volume) principal phase of ferrite or ferrite and bainite and 3% to 50% (volume) of surplus comprise that the complex tissue of martensite or martensite and retained austenite forms:
100≥(A/3+B/6)/(C/6)≥0.01 3。
(17) a kind of galvanizing by dipping sheet metal with high-strength high-tractility of highly corrosion resistant, described galvanizing by dipping sheet metal has one deck coating, and in mass, this coating contains,
Al:0.001～4%, and
Fe: be lower than 5%,
Surplus is zinc and inevitable impurity, in mass, contains on the surface of thin steel sheet
C：0.0001～0.3％，
Si:0.001～be lower than 0.1%,
Mn：0.001～3％，
Al：0.001～4％，
Mo：0.001～1％，
P：0.001～0.3％，
S:0.0001～0.1%, and
Surplus is Fe and inevitable impurity, it is characterized in that, in the coating in Al content A (quality %) and Mo content B (quality %) and the steel Mo content C (quality %) satisfy following formula 3; And the microscopic structure of steel comprises that by 50% to 97% (volume) principal phase of ferrite or ferrite and bainite and 3% to 50% (volume) of surplus comprise that the complex tissue of martensite or martensite and retained austenite forms:
100≥(A/3+B/6)/(C/6)≥0.01 ...3。
(18) (14) any one describedly has the high-strength hot-dip galvanized sheet metal of excellent appearance and machinability and a sheet metal of dip galvanized DIFFUSION TREATMENT in (17), it is characterized in that, the microscopic structure of steel comprises that by 50% to 97% (volume) principal phase of ferrite or ferrite and bainite and 3% to 50% (cumulative volume) of surplus comprise that the complex tissue of martensite or martensite and retained austenite forms.
(19) (14) any one describedly has the high-strength hot-dip galvanized sheet metal of excellent appearance and machinability and a sheet metal of dip galvanized DIFFUSION TREATMENT in (18), it is characterized in that, the microscopic structure of steel has and comprises 70% (volume) to the average grain size of the ferritic principal phase of 97% (volume) and principal phase and be not more than 20 μ m, and comprises 3% (volume) to the average grain size of 30% (volume) austenite and/or martensitic second-phase and second-phase and be not more than 10 μ m.
(20) (14) any one describedly has the high-strength hot-dip galvanized sheet metal of excellent appearance and machinability and a sheet metal of dip galvanized DIFFUSION TREATMENT in (19), it is characterized in that, the steel-sheet second-phase is comprised of austenite; And C content C (quality %) and Mn content Mn (quality %) and austenitic percent by volume V in the steel
γThe percent by volume V of (with %) and ferrite and bainite
α(with %) satisfies following formula 4:
(V
γ+V
α)/V
γ×C+Mn/8≥2.0 ...4。
(21) (14) any one describedly has the high-strength hot-dip galvanized sheet metal of excellent appearance and machinability and a sheet metal of dip galvanized DIFFUSION TREATMENT in (20), it is characterized in that, the steel-sheet microscopic structure has and comprises 50% (volume) to the average grain size of the ferritic principal phase of 95% (volume) and principal phase and be not more than 20 μ m, and comprise 3% (volume) to the average grain size of 30% (volume) austenite and/or martensitic second-phase and second-phase and be not more than 10 μ m, also contain simultaneously 2% (volume) to the bainite of 47% (volume).
(22) (14) any one describedly has the high-strength hot-dip galvanized sheet metal of highly corrosion resistant and a sheet metal of dip galvanized DIFFUSION TREATMENT in (21), it is characterized in that, the austenite of formation sheet metal second-phase and/or martensitic average grain size are 0.01 to 0.6 times of ferrite average grain size.
(23) (1) in (22) any one described high-strength hot-dip galvanized sheet metal with high binding force of cladding material and ductility behind the severe deformation, it is characterized in that, in mass, coating also contains:
Ca：0.001～0.1％，
Mg：0.001～3％，
Si：0.001～0.1％，
Mo：0.001～0.1％，
W：0.001～0.1％，
Zr：0.001～0.1％，
Cs：0.001～0.1％，
Rb：0.001～0.1％，
K：0.001～0.1％，
Ag：0.001～5％，
Na：0.001～0.05％，
Cd：0.001～3％，
Cu：0.001～3％，
Ni：0.001～0.5％，
Co：0.001～1％，
La：0.001～0.1％，
Tl：0.001～8％，
Nd：0.001～0.1％，
Y：0.001～0.1％，
In：0.001～5％，
Be：0.001～0.1％，
Cr：0.001～0.05％，
Pb：0.001～1％，
Hf：0.001～0.1％，
Tc：0.001～0.1％，
Ti：0.001～0.1％，
Ge：0.001～5％，
Ta：0.001～0.1％，
V:0.001～0.2%, and
B：0.001～0.1％
In one or more.
(24) (1) any one describedly has the high-strength hot-dip galvanized sheet metal of excellent appearance and machinability and a sheet metal of dip galvanized DIFFUSION TREATMENT in (23), it is characterized in that, in mass, also contain in the steel,
Cr：0.001～25％，
Ni：0.001～10％，
Cu：0.001～5％，
Co:0.001～5%, and
W：0.001～5％
In one or more.
(25) (1) any one describedly has sheet metal excellent appearance and machinability, high-strength hot-dip galvanized sheet metal and dip galvanized DIFFUSION TREATMENT in (24), it is characterized in that, in mass, also containing total amount in the steel is among 0.001 to 1% Nb, Ti, V, Zr, Hf and the Ta one or more.
(26) (1) any one describedly has the high-strength hot-dip galvanized sheet metal of excellent appearance and machinability and a sheet metal of dip galvanized DIFFUSION TREATMENT in (25), it is characterized in that, in mass, also containing total amount in the steel is 0.0001 to 0.1% B.
(27) (1) any one describedly has the high-strength hot-dip galvanized sheet metal of excellent appearance and machinability and a sheet metal of dip galvanized DIFFUSION TREATMENT in (26), it is characterized in that, in mass, also contain among 0.0001 to 1% Y, Rem, Ca, Mg and the Ce one or more in the steel.
(28) (1) in (27) any one described sheet metal with high strength, high ductibility galvanizing by dipping sheet metal and dip galvanized DIFFUSION TREATMENT of high antifatigue and highly corrosion resistant, it is characterized in that, in area percentage, in the scope from the interface between coating and the sheet metal to the 10 μ m degree of depth, contain total amount in the steel and be 0.1 to 70% SiO
2, MnO and Al
2O
3In one or more; And satisfy following formula 5:
{ MnO (% (area))+Al
2O
3(% (area)) }/SiO
2(% (area)) 〉=0.1 ... 5.
(29) (1) any one describedly has the high-strength high-tractility galvanizing by dipping sheet metal of high antifatigue and highly corrosion resistant and a sheet metal of dip galvanized DIFFUSION TREATMENT in (28), it is characterized in that, in area percentage, from the interface between coating and the sheet metal in 10 μ m depth boundses, contain total amount in the steel and be 0.0001 to 10.0% Y
2O
3, ZrO
2, HfO
2, TiO
3, La
2O
3, Ce
2O
3, CeO
2, among CaO and the MgO one or more.
(30) a kind of for the preparation of having high binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility and the steel-sheet method of dip galvanized DIFFUSION TREATMENT behind the severe deformation, it is characterized in that, to comprise (1) the steel casting of any one described chemical composition in (29), perhaps after casting, cool off bloom slab once; And then heat above-mentioned bloom slab; Then bloom slab is rolled into hot rolled steel sheet and it is batched, then pickling and cold rolling above-mentioned hot rolled steel sheet; Then, be not less than 0.1 * (Ac
3-Ac
1)+Ac
1(℃) to not being higher than Ac
3+ 50 (℃) temperature range in, with above-mentioned cold-reduced sheet annealing 10 seconds to 30 minutes; Then with the cooldown rate of 0.1～10 ℃/sec, above-mentioned sheet metal is cooled to 650 to 700 ℃ temperature range; Then, with the cooldown rate of 1～100 ℃/sec, above-mentioned sheet metal is cooled to bath temperature to the temperature range of bath temperature+100 ℃; Sheet metal is remained on the zinc bath temperature reach 1 to 3000 second to the temperature range of zinc bath temperature+100 ℃, the above-mentioned time comprises dip time subsequently; Sheet metal is immersed in the zinc plating bath; Afterwards, above-mentioned sheet metal is cooled to room temperature.
(31) a kind of for the preparation of (1) in (29) the steel-sheet method of any one described high-strength hot-dip galvanized sheet metal and dip galvanized DIFFUSION TREATMENT, described galvanizing by dipping sheet metal has fabulous outward appearance and machinability, it is characterized in that, to comprise such as the steel of chemical composition casting as described in any one in (1) to (29), perhaps after casting, cool off bloom slab once; And then heat above-mentioned bloom slab and reach 1180 to 1250 ℃; Temperature at 880 to 1100 ℃ is finished hot rolling; Then pickling and the cold rolling above-mentioned hot rolled steel sheet that batches; Then, be not less than 0.1 * (Ac
3-Ac
1)+Ac
1(℃) to not being higher than Ac
3+ 50 (℃) temperature range in, with above-mentioned cold-reduced sheet annealing 10 seconds to 30 minutes; Then with the cooldown rate of 0.1～10 ℃/sec, above-mentioned sheet metal is cooled to 650 to 700 ℃ temperature range; Then, with the cooldown rate of 0.1～100 ℃/sec, above-mentioned sheet metal is cooled to bath temperature-50 ℃ to the temperature range of bath temperature+50 ℃; Then sheet metal is immersed in the plating bath; Sheet metal is remained on bath temperature-50 ℃ reach 2 to 200 seconds to the temperature range of bath temperature+50 ℃, the above-mentioned time comprises dip time; Afterwards, above-mentioned sheet metal is cooled to room temperature.
(32) a kind of for the preparation of (1) in (29) the steel-sheet method of any one described high-strength high-tractility galvanizing by dipping sheet metal and dip galvanized DIFFUSION TREATMENT, described galvanizing by dipping sheet metal has fabulous corrosion resistance, it is characterized in that, to comprise such as the steel of chemical composition casting as described in any one in (1) to (29), perhaps after casting, cool off bloom slab once; And then heat above-mentioned bloom slab and reach 1200 to 1300 ℃; Then with 60 to 99% total reduction, under 1000 to 1150 ℃ temperature, the heated bloom slab of roughing; Then pickling and cold rolling above-mentioned fine finishining and the hot rolled steel sheet that batches; Then, be not less than 0.12 * (Ac
3-Ac
1)+Ac
1(℃) to not being higher than Ac
3+ 50 (℃) temperature range in, with above-mentioned cold-reduced sheet annealing 10 seconds to 30 minutes; Then, after the annealing, the highest annealing temperature in the time will annealing be defined as Tmax (℃) time, with the cooldown rate of Tmax/1000-Tmax/10 ℃/sec, above-mentioned sheet metal is cooled to Tmax-200 ℃ to Tmax-100 ℃ temperature range; Then, with the cooldown rate of 0.1～100 ℃/sec, above-mentioned sheet metal is cooled to bath temperature-30 ℃ to the temperature range of bath temperature+50 ℃; Then sheet metal is immersed in the plating bath; Sheet metal is remained on bath temperature-30 ℃ reach 2 to 200 seconds to the temperature range of bath temperature+50 ℃, the above-mentioned time comprises dip time; Afterwards, above-mentioned sheet metal is cooled to room temperature.
(33) a kind of steel-sheet method of the high-strength high-tractility galvanizing by dipping sheet metal dip galvanized DIFFUSION TREATMENT for the preparation of having high antifatigue and highly corrosion resistant, it is characterized in that, to comprise (1) the steel casting of any one described chemical composition in (29), perhaps after casting, cool off bloom slab once; And then heat above-mentioned bloom slab; Then bloom slab is rolled into hot rolled steel sheet and it is batched, then pickling and cold rolling above-mentioned hot rolled steel sheet; Then, the control annealing temperature is not less than 0.1 * (Ac so that the maximum temperature in when annealing can drop on
3-Ac
1)+Ac
1(℃) to not being higher than Ac
3-30 (℃) temperature range in the annealing of above-mentioned cold-reduced sheet; Then with the cooldown rate of 0.1～10 ℃/sec, above-mentioned sheet metal is cooled to 650 to 710 ℃ temperature range; Then, with the cooldown rate of 1～100 ℃/sec, above-mentioned sheet metal is cooled to the zinc bath temperature to the temperature range of zinc bath temperature+100 ℃; Sheet metal is remained on the zinc bath temperature reach 1 to 3000 second to the temperature range of zinc bath temperature+100 ℃, the above-mentioned time comprises dip time subsequently; Sheet metal is immersed in the zinc plating bath; Afterwards, cool off above-mentioned sheet metal to room temperature.
(34) a kind of have a high antifatigue, highly corrosion resistant, the sheet metal of the high strength hot dipping zinc of high binding force of cladding material and ductility plating sheet metal and dip galvanized DIFFUSION TREATMENT behind the severe deformation, and (30) any one is described for the preparation of having high antifatigue in (33), highly corrosion resistant, the steel-sheet method of the high-strength hot-dip galvanized sheet metal of high binding force of cladding material and ductility and dip galvanized DIFFUSION TREATMENT behind the severe deformation, it is characterized in that, after sheet metal being immersed in the zinc plating bath, carry out Alloying Treatment at 300 to 550 ℃, then sheet metal is cooled to room temperature.
Realize best mode of the present invention
To describe the present invention in detail below.
Embodiment 1
The inventor is in mass a kind of, the C by 0.0001～0.3%, 0.001～2.5% Si, 0.01～3% Mn, 0.001～4% Al and the iron of surplus and inevitably the sheet metal that forms of impurity process: be not less than 0.1 * (Ac
3-Ac
1)+Ac
1(℃) to not being higher than Ac
3+ 50 (℃) temperature range in, with above-mentioned cold-reduced sheet annealing annealing in 10 seconds to 30 minutes; Then with the cooldown rate of 0.1～10 ℃/sec, above-mentioned sheet metal is cooled to 650 to 700 ℃ temperature range; Then, with the cooldown rate of 1～100 ℃/sec, above-mentioned sheet metal is cooled to bath temperature (450 to 470 ℃) to the temperature range of bath temperature+100 ℃; Sheet metal was flooded for 3 seconds in 450 to 470 ℃ of zinc plating baths; 500 to 550 ℃ of heating 10 to 60 seconds of sheet metal.
Then, assess plating performance by measuring by the area of plating leakage part on the plating surface of thin steel sheet.By salt spray test assessment corrosion resistance repeatedly.Carry out plain bending fatigue test assessment by plating steel-sheet fatigue behaviour also by tension test assessment mechanical performance, and by the pressure that applies corresponding to sheet metal tensile strength 50%.
Further, after applying 20% stretcher strain, by sheet metal is applied 60 ° of bendings and backward bending forming assess binding force of cladding material.The polyethylene band is sticked on the part of carrying out behind the bending forming and it is peeled off, then measure the area that coating is stripped from by graphical analysis.
The result, especially, observe a large amount of Si system oxides on the grain boundary at the interface between coating and the basic unit, and, the inventor finds, relation between the form of considering the grain boundary oxide layer and fatigue behaviour, by the depth capacity of control grain boundary oxide layer and in the final microscopic structure that obtains the average particle size particle size of principal phase, can prepare a kind of galvanizing by dipping sheet metal fabulous fatigue resistance and corrosion resistance, high strength, high ductibility that has.
That is, the inventor finds, contains the depth capacity of the grain boundary oxide layer of 0.5 μ m or less Si on the crystal boundary between coating and the basic unit by being controlled at, the final microscopic structure that obtains, and can prolong galvanizing by dipping steel-sheet fatigue life.In addition, by selecting composition and the preparation condition of steel, can prolong further galvanizing by dipping steel-sheet fatigue life.It is 0.5 μ m or less that described preparation condition allows the depth capacity of grain boundary oxide layer, more preferably 0.2 μ m or less.
In addition, the inventor finds, kind and area percentage by oxide in the restriction steel can improve corrosion resistance and fatigue resistance further after alloying is processed, contain grain boundary oxide at the depth bounds from the interface between coating and sheet metal to 10 μ m in the steel.That is, a kind of sheet metal with high strength, high ductibility galvanizing by dipping sheet metal or dip galvanized DIFFUSION TREATMENT of excellent corrosion resistance, fatigue resistance can obtain by following manner: as oxide, make and contain SiO in the steel
2, MnO and Al
2O
3In one or more, it occupies 0.4 to 70% of gross area percentage in the depth bounds from the interface between coating and the sheet metal to 10 μ m, and controls above-mentioned area percentage and make it to satisfy following expression formula:
{ MnO (% (area)) Al
2O
3(% (area)) }/SiO
2(% (area)) 〉=0.1.
The inventor also finds, by removing SiO
2, MnO and Al
2O
3Outside, in the depth bounds from the interface between coating and the sheet metal to 10 μ m, add Y with 0.0001 to 10.0%, Xiang Gangzhong of gross area percentage
2O
3, ZrO
2, HfO
2, TiO
2, La
2O
3, Ce
2O
3, CeO
2, among CaO and the MgO one or more, also can after Alloying Treatment, improve corrosion resistance and fatigue resistance.
The measurement that as mentioned above, is present in evaluation, observation and the area percentage of the oxide the steel in the depth bounds of 10 μ m at the interface between coating and sheet metal herein, can be undertaken by using EPMA, FE-SEM and similar approach.Among the present invention, under 2000 to 20000 magnifying power, by measuring the area more than 50 visual fields, then the analysis data with graphical analysis obtain area percentage.Identify oxide by the reproduction copies of preparation extraction and with TEM or EBSP.Distinguish above-mentioned MnO, Al by find the most similar object with elementary analysis and Structural Identification
2O
3And SiO
2Although sometimes having object is the situation that contains the composite oxides of other atom or have the structure of a lot of defectives.Obtain area percentage by the area scanning that carries out each composition with EPMA, FE-SEM and similar approach.In this case, be difficult although accurately identify each structure, but still can judge together by form, tissue and said structure analysis.Then, can be by the data that obtained by area scanning be carried out the percentage that graphical analysis obtains each area.
The inventor finds, is not more than in 20 μ m and the microscopic structure by the average particle size particle size of controlling principal phase in the sheet metal, and the depth capacity of the grain boundary oxide layer on interface between coating and the basic unit is not more than 1 μ m can prolong fatigue life equally.In addition, they find, come to remove the value that the depth capacity that is formed on the grain boundary oxide layer on the interface between coating and the basic unit obtains by control with principal phase average particle size particle size in the sheet metal microscopic structure, can obtain a kind of sheet metal with high strength, high ductibility galvanizing by dipping sheet metal and dip galvanized DIFFUSION TREATMENT of excellent fatigue resistance and corrosion resistance.
In addition, about plating performance and corrosion resistance, have found that, as long as Si content: X (quality %) in the sheet metal, Al content: A (quality %) and Mn content: B (quality %) satisfy following formula 1 in Mn content: Y (quality %) and Al content: Z (quality %) and the coating, even when in sheet metal, containing a large amount of especially Si, also can not form the plating leakage defective, and the formation of becoming rusty is also considerably less in salt spray test repeatedly:
3-(X+Y/10+Z/3)-12.5×(A-B)≥0 ...1。
Formula 1 is to show when composition in sheet metal and the coating is to the wetting sex data of plating newfound by multiple regression analysis.
Herein, coating is determined composition in the coating by the chemical analysis measured value after being contained dissolving with hydrochloric acid corrosion inhibiter, 5%.
Embodiment 2
The inventor is in mass a kind of, by
C：0.0001～0.3％，
Si:0.001～be lower than 0.1%,
Mn：0.01～3％，
Al：0.001～4％，
Mo：0.001～1％，
P：0.0001～0.3％，
S：0.0001～0.1％，
And the sheet metal of the iron of surplus and inevitable impurity composition is handled as follows: with above-mentioned sheet metal annealing; Sheet metal was flooded for 3 seconds in 450 to 470 ℃ zinc plating bath; And then at 500 to 530 ℃ with 10 to 60 seconds of sample segment heating.Then, the defective that occurs on the surface of thin steel sheet with plating is divided into 5 grades and assesses the surface.Mechanical performance is assessed with tension test.Found that, Mn content is defined as X (quality %) and Si content is Y (quality %) in steel, and Al content is Z (quality %) and X, Y and Z when satisfying following formula 2 in the coating:
0.6-(X/18+Y+Z)≥0 ...2
Can evaluation grade 5, it is a kind of grade that does not almost observe blemish that means.
Can assess by plating steel-sheet surface by the state of vision observation plating leakage defective formation and the formation state of flaw and decorative pattern (patterns), and they are divided into 1 to 5 evaluation grade.Evaluation criteria is as follows:
Evaluation grade 5: almost do not observe plating leakage defective, flaw and decorative pattern (area percentage no more than 1%),
Evaluation grade 4: plating leakage defective, flaw and the decorative pattern (area percentage is more than 1% to no more than 10%) of trace are arranged,
Evaluation grade 3: a small amount of plating leakage defective, flaw and decorative pattern (area percentage is more than 10% to no more than 50%) are arranged,
Evaluation grade 2: a large amount of plating leakage defective, flaw and decorative pattern (area percentage is more than 50%) are arranged,
Evaluation grade 1: plating can not wetting surface of thin steel sheet.
Embodiment 3
The inventor is in mass a kind of, by
C：0.0001～0.3％，
Si:0.001～be lower than 0.1%,
Mn：0.013％，
Al：0.001～4％，
Mo：0.001～1％，
P：0.0001～0.3％，
S：0.0001～0.1％，
And the sheet metal of the iron of surplus and inevitable impurity composition is handled as follows: with above-mentioned sheet metal annealing; Sheet metal was flooded for 3 seconds in 450 to 470 ℃ zinc plating bath; And then at 500 to 550 ℃, sample segment was heated for 10 to 60 seconds.Then, sheet metal is carried out sufficient flat wise bend (R=1t); Then, based on the Society of Automotive Engineers of Japan, Inc.(JASE) standard (JASO) is carried out cycle corrosion test up to 150 circulations with crooked sample.By using light microscope, the magnifying power 200 to 1000 is observed the appearance that is no less than 20 visual fields and section outward appearance with the evaluation of corrosion state; Observe the degree that Corrosion developing enters the inside, and observed result is divided into 5 grades.Evaluation criteria is as follows:
Evaluation grade 5: Corrosion developing degree: only the corrosion depth of corrosion of coating or base material is lower than 50 μ m,
Evaluation grade 4: Corrosion developing degree: the corrosion depth of base material is 50 μ m to being lower than 100 μ m,
Evaluation grade 3: Corrosion developing degree: the corrosion depth of base material is lower than half of sheet metal thickness,
Evaluation grade 2: Corrosion developing degree: the corrosion depth of base material is not less than half of sheet metal thickness,
Evaluation grade 1: perforation.
The result, find in coating Al content in 0.001 to 4% scope and be defined as A (quality %), Mo content is defined as B (quality %) in the coating, Mo content is defined as C (quality %) in the steel, and when A, B and C satisfy following formula 3, can obtain the good evaluation grade of corrosion resistance 4 or 5:
100≥(A/3+B/6)/(C/6)≥0.01 ...3
Why repressed detailed reason may not be clearly to the plating leakage defective entirely, is owing to the Al and the SiO that is formed on surface of thin steel sheet that are added in the plating bath but estimate to produce the plating leakage defect cause
2Between the poor cause of wettable.So the generation that usually suppresses the plating leakage defective by adding the unit that can remove the Al adverse effect that is added in the zinc plating bath is possible.As the result that the inventor conscientiously studies, find to achieve the above object by the Mn that adds the debita spissitudo scope.Estimate Mn and preferentially form oxide-film and therefore strengthened it with the reactivity that is formed on the Si system oxide-film on the surface of thin steel sheet than the Al that is added in the zinc plating bath.
In addition, according to estimates, suppressing the Si squama that produced by the caused flaw that forms during the hot rolling by reducing Si content in the steel, also is effective to improving outward appearance.In addition, consider that the minimizing of following Si content can cause the reduction of quality of materials, find can obtain ductility by regulating preparation condition and adding other composition for example Al and Mo, find simultaneously when accelerating alloying, it is effective reducing Si content and adding Al.
Although reason and unclear estimates it is because different (electromotive force is different) of the form of the generation of plating leakage defective, other defective and base material and corrosion resistance of coating cause in detail.
Herein, although the not special regulation of the deposition of plating, from corrosion proof angle, preferably the deposition on a side surface is no less than 5g/mm
2Although in order to improve paintability and wettable performance a kind of upper strata is applied for galvanizing by dipping sheet metal of the present invention, and with multiple processing for example chromaking is processed, phosphatization is processed, lubricity improve process, weldability improves to process etc. and is used for galvanizing by dipping sheet metal of the present invention, but these measures do not depart from the present invention.
The preferred microscopic structure of base steel sheet
The preferred microscopic structure of base steel sheet then, is described below.In order fully to obtain ductility, preferably make principal phase be organized as ferritic phase.Yet, when the higher intensity of needs, can contain Bainite Phases of Some, but from obtaining the angle of ductility, the expectation principal phase contains by volume, be not less than 50%, preferred 70% ferritic single-phase or the compound phase of ferrite and bainite (term " ferrite or ferrite and bainite " except special instruction is arranged, the same with the meaning of describing in the specification).In the situation of compound phase that is ferrite and bainite, in order to obtain reliable ductility, the ferrite that expectation contains is not less than 50% by volume.On the other hand, in order to guarantee high strength and high ductibility with good balance mode, the ferrite that preferably contains or ferrite and bainite by volume, no more than 97%.In addition, in order to guarantee simultaneously high strength and high ductibility, being organized as of expectation contains retained austenite and/or martensitic complex tissue.In order to guarantee simultaneously high strength and high ductibility, preferably contain by volume, be no less than 3% retained austenite and/or martensite.But if total value surpasses 50%, then sheet metal is easily crisp, so the above-mentioned value of desired control is no more than 30% by volume.
In order to guarantee the high ductibility of sheet metal self, stipulate that austenite and/or martensitic average particle size particle size that ferritic average particle size particle size is not more than 20 μ m and forms second-phase are not more than 10 μ m.Herein, the expectation second-phase is comprised of austenite and/or martensite, and austenite and/or martensitic average particle size particle size is not more than form 0.7 times of ferritic average particle size particle size of principal phase.But, owing in actual fabrication process, being difficult to make the austenite that forms second-phase and/or martensitic average particle size particle size less than 0.01 times of ferritic average particle size particle size, so preferred ratio is for being not less than 0.01.
In addition, for guarantee good binding force of cladding material and well balance guarantee high strength and high ductibility, in the situation that the sheet metal second-phase is made of C content: C (quality %) and Mn content: Mn (quality %) and austenitic percent by volume: V in the regulation steel austenite
γThe percent by volume of (with %) and ferrite and bainite: V
α(with %) satisfies following formula 4:
(V
γ+V
α)/V
γ×C+Mn/8≥2.0 ...4
By satisfying above-mentioned expression formula, can obtain all fabulous, sheet metals with good binding force of cladding material of intensity and ductility.
Explained later is in the situation that contain percent by volume and the similar content of bainite.In order to improve intensity, by volume, it is effectively containing and being no less than 2% Bainite Phases of Some, and, when it exists mutually jointly with austenite, help stable austenite, as a result of, help to guarantee high n value.In addition, above-mentioned phase constitution is tiny basically, therefore also can help the adhesiveness of coating between strong operational period.Especially, in the situation that second-phase is comprised of austenite, be not less than 2% by the percent by volume of controlling bainite, applying adhesiveness and ductility can further improve evenly.On the other hand, because ductility is worsened, so being restricted to, the percent by volume of Bainite Phases of Some is not higher than 47%.
Except foregoing, be used for sheet metal of the present invention and comprise that those contain one or more the sheet metal that is not higher than by volume in 1% the carbide as the microstructure nubbin, nitride, sulfide and the oxide.Herein, by use potassium nitrate reagent or in unexamined Japanese Patent Application Publication specification S59-219473 disclosed reagent in rolling direction or cross-directional etching steel-sheet cross section, can carry out the percent by volume of remnant tissue in each phase, interface oxide layer thing and the microscopic structure in the observation, average particle size particle size (particle size of average circle of equal value) of quantitative detection evaluation, position and ferrite, bainite, austenite, the martensite, and under 500 to 1000 magnifying power, observe horizontal interface by light microscope.
Sometimes have the situation that almost can not measure the martensite particle size by light microscope herein.In the sort of situation, can pass through to observe the border of martensitic whole block (blocks), splicing object (packets) or aggregation (aggregates), and obtain average round particle size of equal value with sweep electron microscope measurement particle size.
In addition, use sweep electron microscope and transmission electron microscope at the interface the form of grain boundary oxide layer between coating and the basic unit is observed and to identify, by observing the degree of depth that is no less than 20 visibility regions under 1000 the magnifying power and measure depth capacity being not less than, and determine its maximum.
Average particle size particle size is defined as so that with said method, by being the basis in the result who is no less than 20 visibility region objects of observation acquisitions, by the value of regulated procedure acquisition among the JIS
Then, coating will be described below.
In mass, preferably Al content in the coating is controlled at 0.001 to 0.5% scope.This be because, in mass, when Al content is lower than 0.001%, significantly form dregs and therefore can not obtain good outward appearance, and, in mass, when the Al that adds surpasses 0.5%, significantly suppressed alloying reaction and therefore formed hardly hot dipping alloy zinc coat.
In mass, why Mn content is arranged on the reason of 0.001 to 2% scope and is in the coating, in this scope, does not produce the plating leakage defective and can obtain the coating of good appearance.In mass, when Mn content surpassed 2%, the Mn-Zn compound deposited and enters coating in plating bath, cause outward appearance significantly to worsen.
In addition, in the situation that special expectation has spot weldability and coating, can improve above-mentioned performance by using Alloying Treatment.Especially, after sheet metal is submerged in the zinc plating bath, under 300 to 550 ℃, by using Alloying Treatment, can makes Fe enter coating, thereby obtain a kind of high-strength hot-dip galvanized sheet metal with fabulous paintability and spot welding characteristics.After Alloying Treatment, in mass, when Fe content was lower than 5%, spot welding characteristics was good not.On the other hand, in mass, when Fe content surpassed 20%, therefore the adhesion of coating self worsens also made coating destruction, peel off and cling during operation mould, cause the crack during forming.So when using Alloying Treatment, in mass, the Fe content in the coating is arranged on 5 to 20%.
In addition, find to suppress the plating leakage defective by in coating, containing among Ca, Mg, Si, Mo, W, Zr, Cs, Rb, K, Ag, Na, Cd, Cu, Ni, Co, La, Tl, Nd, Y, In, Be, Cr, Pb, Hf, Tc, Ti, Ge, Ta, V and the B one or more.
, although the coating deposition amount is not stipulated especially, consider from corrosion proof angle, preferably the deposition at a side surface is not less than 5g/mm herein
2Although in order to improve paintability and solderability, in galvanizing by dipping sheet metal of the present invention, use a kind of upper strata plating, for example chromaking is processed, phosphatization is processed, lubricity improves processing, the weldability raising is processed etc. but can use multiple processing in galvanizing by dipping sheet metal of the present invention, and these situations do not depart from the present invention.
As a kind of impurity in the coating, Mn is an example.When Mn content in the coating increases to conventional levels above impurity, produce hardly the plating leakage defective.Yet, because the restriction of relevant electroplating device, the very difficult content that increases Mn in the coating.So the present invention allows Mn content in mass, is not less than 0.001%, above-mentioned content is in the level of impurity element, and this point is an invention, wherein, even not being to have a mind when adding Mn in the plating bath, also can obtain the sheet metal of minimum plating leakage defective and blemish.
Stipulate lower column element in mass, in described scope: Ca:0.001～0.1%, Mg:0.001～3%, Si:0.001～0.1%, Mo:0.001～0.1%, W:0.001～0.1%, Zr:0.001～0.1%, Cs:0.001～0.1%, Rb:0.001～0.1%, K:0.001～0.1%, Ag:0.001～5%, Na:0.001～0.05%, Cd:0.001～3%, Cu:0.001～3%, Ni:0.001～0.5%, Co:0.001～1%, La:0.001～0.1%, Tl:0.001～8%, Nd:0.001～0.1%, Y:0.001～0.1%, In:0.001～5%, Be:0.001～0.1%, Cr:0.001～0.05%, Pb:0.001～1%, Hf:0.001～0.1%, Tc:0.001～0.1%, Ti:0.001～0.1%, Ge:0.001～5%, Ta:0.001～0.1%, V:0.001～0.2% and B:0.001～0.1%, its reason is: in each scope, the suppressed coating with obtaining having good appearance of plating leakage defective.Prescribe a time limit when each element surpasses on each, form the dregs that contain each element, thereby the plating outward appearance worsens significantly.
Then, the reason of composition range in the interpretation steel of the present invention below.
For the balance of proof strength and ductility well, need to guarantee the percent by volume of second-phase, be exactly for abundant assurance percent by volume and add the C element.Especially, when second-phase was comprised of austenite, C not only helped to guarantee the acquisition of percent by volume, and therefore helped stability and a large amount of ductility that improves.For the percent by volume of proof strength and second-phase, in mass, lower limit is set to 0.0001%.In order to keep solderability, in mass, the upper limit is set to 0.3%.
Adding the Si element is to be used to form the ferritic formation of principal phase and the formation that inhibition can cause the carbide that balance worsens between intensity and the ductility in order to promote, in mass, lower limit is set to 0.01%.On the other hand, its excessive interpolation can cause adverse effect to weldability and plating wettability again.In addition, because C promotes the formation of inner grain boundary oxide layer, so C must be suppressed in reduced levels.So in mass, the upper limit is set to 2.5%.Especially, when being outward appearance, for example scale defective or analog become problem, rather than intensity determines in mass when becoming problem, and C is reduced to 0.001%, and this numerical value is not positioned at can cause the operational issue scope.
The purpose of adding Mn is not only in order to control plating wettable and plating adhesion, and is in order to improve intensity.In addition, add it also for the precipitation that suppresses carbide with can cause intensity and pearlitic formation that ductility worsens.For this reason, Mn content is set to and is not less than 0.001% in mass.On the other hand, since when second-phase is comprised of austenite, Mn can postpone to help the conversion of bainite, and this conversion is favourable to ductility, but unfavorable to solderability, so in mass, the upper limit of Mn is set to 3%.
Al can control plating wetability and binding force of cladding material and especially effectively, when second-phase is comprised of austenite, can promote to help to improve the transformation of the bainite of ductility, and Al can also improve the balance between intensity and the ductility.In addition, Al also is a kind of element that can effectively suppress the inner grain boundary oxide formation of Si system.So the addition of Al is set in mass, is not less than 0.0001%.On the other hand, because its excessive interpolation can significantly worsen again solderability and plating wettability and therefore significantly suppress synthetic reaction, therefore, in mass, its upper limit is set to 4%.
Adding Mo is in order to suppress carbide and can to cause intensity and the pearlitic formation of ductility deterioration.Under the heat-treat condition that relaxes, Mo is important element well balanced between proof strength and ductility.So in mass, the lower limit of Mo is set to 0.001%.In addition, owing to its excessive interpolation produces retained austenite, reduces stability and makes the ferrite hardening cause ductility to worsen, so its upper limit is set to 5%, is preferably 1%.
Add Mg, Ca, Ti, Y, Ce and Rem and be in order to suppress to cause the generation of the inner grain boundary oxide layer of Si system that plating wettable, fatigue resistance and corrosion resistance worsen.Because these elements do not produce grain boundary oxide such as Si is oxide, but can produce quite tiny oxide by dispersing mode, the oxide of above-mentioned element self does not have adverse effect to fatigue resistance.In addition, because these elements have suppressed the generation of the inner grain boundary oxide layer of Si system, so the degree of depth of inner grain boundary oxide layer can reduce, therefore above-mentioned element helps to prolong fatigue life.Can add in the above-mentioned element one or more, the addition of these elements is set to and is not less than 0.0001% in gross mass.On the other hand, because the manufacturability that their excessive interpolation can worsen the sheet metal product for example casting character and hot-workability and ductility, therefore in mass, its upper limit is set to 1%.
In addition, in order to improve intensity, steel of the present invention can contain one or more among Cr, Ni, Cu, Co and the W.
Add Cr and be in order to improve intensity and to suppress the generation of carbide, in mass, addition is set to and is not less than 0.001%.But in mass, meeting baneful influence machinability when its addition surpasses 25% is so above-mentioned value is confirmed as the upper limit.
Ni can be used for improving plating performance and improves intensity, in mass, determines that Ni content is not less than 0.001%.But in mass, meeting baneful influence machinability when its addition surpasses 10% is so above-mentioned value is confirmed as the upper limit.
Cu can be used for improving intensity, and in mass, the addition of Cu is not less than 0.001%.But in mass, meeting baneful influence machinability when its addition surpasses 5% is so above-mentioned value is confirmed as the upper limit.
Co can be used for transformation by control plating performance and bainite and improves balance between intensity and the ductility, and the addition of Co is not less than 0.001%.Its upper limit is not made special regulation, still because Co is expensive element, add in a large number uneconomical, so in mass, the addition that expectation is set is not higher than 5%.
In mass, W content is defined in 0.001 to 5% scope, and its reason is: in mass, when content is not less than 0.001%, show the high-intensity effect of proposing; But when addition surpasses 5%, can have a negative impact to machinability.
In addition, can contain among Nb, Ti, V, Zr, Hf and the Ta one or more in the steel of the present invention, they are the elements that strongly form carbide, also can be used for further improving intensity.
Above-mentioned element forms tiny carbide, nitride or carboritride and very effective to strengthening sheet metal.So, in mass, determine that the needs interpolation is not less than one or more in the 0.001% above-mentioned element.On the other hand, enter in the retained austenite because above-mentioned element can worsen ductility and obstruction C is concentrated, in mass, therefore, the upper limit of total addition level is set to 1%.
Also need to add B.In mass, add that to be not less than 0.0001% B be effective for strengthening crystal boundary and Steel material.But when in mass, when its addition surpassed 0.1%, not only effect had reached saturated, and the increase of sheet metal intensity surpassed needs, and the result causes the deterioration of machinability, so in mass, the upper limit is set to 0.1%.
In mass, P content is defined in 0.0001 to 0.3% the scope, and its reason is: in mass, when content is not less than 0.0001%, show the high-intensity effect of proposing; And ultralow P is unfavorable economically; When addition surpasses 0.3%, can the productivity during solderability and casting and the hot rolling be had a negative impact.
In mass, S content is defined in 0.0001 to 0.1% the scope, and its reason is: in mass, the ultralow S that is lower than lower limit 0.0001% is unfavorable economically; When addition surpasses 0.1%, can the productivity during solderability and casting and the hot rolling be had a negative impact.
P, S, Sn etc. are inevitable impurity.In mass, expectation P content is no more than 0.05%, S content no more than 0.01% and Sn content no more than 0.01%.As everyone knows, adding especially a small amount of P is effective for the balance of improving between intensity and the ductility.
The below will explain that preparation has the high-strength hot-dip galvanized steel-sheet method of above-mentioned tissue.
According to the present invention, when by hot rolling, cold rolling and annealing preparation sheet metal, cast and a kind ofly be adjusted to the bloom slab of predetermined component or after casting, cool off once, then it is heated and hot rolling again being not less than under 1180 ℃ the temperature.At this moment, in order to suppress the formation of grain boundary oxide layer, expectation again heating-up temperature is set as and is not less than 1150 ℃ or be not higher than 1100 ℃.When heating-up temperature became very high again, oxidation squama tendency was formed uniformly on whole surface, and so just trend has suppressed the oxidation of crystal boundary.
But, can promote intensely local oxidation when being heated to when surpassing 1250 ℃ temperature, so this temperature is confirmed as the upper limit.
Low-temperature heat has postponed the formation of oxide layer self.
In addition, in order to suppress the formation of too much subscale, determine to finish hot rolling being not less than 880 ℃.In order to reduce the grain boundary oxide degree of depth of product, preferably after hot rolling by high-pressure descale apparatus or use a large amount of pickling and remove surperficial squama.Afterwards, the cold rolling and annealing with sheet metal, thus obtain final products.In this case, usually the hot rolling final temperature is controlled to be and is not less than Ar
3Transition temperature, this temperature determines by the chemical composition of steel, still, as long as temperature is up to than Ar
3Approximately hang down 10 ℃ temperature, the performance of final sheet metal product just can not worsen.
But for fear of a large amount of formation oxidation squamas, the hot rolling final temperature is set to and is not higher than 1100 ℃.
In addition, be not less than the bainite start point temperature by controlling cooled coiling temperature, this temperature determines by the chemical composition of steel, just can avoid increasing too much during cold rolling and load.But, total this and be not suitable for the very low situation of percent reduction when cold rolling, and even sheet metal batches under the transition temperature that is not higher than bainite in the steel, final sheet metal properties of product can not worsen yet.In addition, cold rolling total reduction is determined by the relation between final thickness and the cold rolling load, as long as total reduction is not less than 40%, is preferably 50%, this numerical value is exactly that effectively final sheet metal properties of product can not worsen yet for reducing the grain boundary oxide degree of depth.
In the annealing process after cold rolling, when annealing temperature be lower than by the chemical composition of steel determine by Ac
1Temperature and Ac
30.1 * (the Ac that temperature is expressed
3-Ac
1)+Ac
1(℃) value (for example, with reference to " TekkoZairyo Kagaku ": W.C.Leslie, Supervisory Translator:Nariyasu Koda, Maruzen, p.273) time, the austenitic amount that During Annealing forms is very little, does not keep like this retained austenite phase or martensitic phase in final sheet metal, so this value is confirmed as the lower limit of annealing temperature.Herein, annealing temperature is higher, promotes that the grain boundary oxide layer that forms is more.
Because high annealing causes promoting to form the grain boundary oxide layer, preparation cost increases, so the upper limit of annealing temperature is confirmed as Ac
3-30 (℃).Especially, annealing temperature is more near Ac
3(℃), promote that the grain boundary oxide layer that forms is more.In this temperature range, for balance sheet metal temperature and assurance austenite, need to be no less than 10 seconds annealing time.But, when the annealing time more than 30 minutes, promoted the formation of grain boundary oxide layer and increased cost.So the upper limit is set to 30 minutes.
After this preliminary cooling is important the transition process that promotes from austenite to ferritic phase, and comes stable austenite by the C that concentrates in mutually at austenite before transformation.
When the maximum temperature of During Annealing be defined as Tmax (℃) time, it is unfavorable that the cooling rate that is lower than Tmax/1000 ℃/sec. can bring in the preparation, for example causes prolonging the technological process line and significantly reduce output.On the other hand, when cooling rate surpassed Tmax/10 ℃/sec., ferritic transformation was insufficient, almost can not guarantee the retained austenite in the final sheet metal product, for example martensitic phase of a large amount of hard phases occurred.
When the maximum temperature of During Annealing be defined as Tmax (℃) and up to being lower than when tentatively cooling off under Tmax-200 ℃ the temperature, produce pearlite and during cooling ferrite produce insufficient, so this temperature is confirmed as lower limit.But when preliminary cooling is surpassing when ending under Tmax-100 ℃ the temperature, ferritic transformation is insufficient, so this temperature is confirmed as the upper limit.
Be lower than 0.1 ℃/sec. cooldown rate and promote that the formation of grain boundary oxide layer is also therefore unfavorable to producing, for example cause prolonging the technological process line and significantly reduce output.So the lower limit of cooling rate is confirmed as 0.1 ℃/sec..On the other hand, when cooling rate surpassed 10 ℃/sec., ferritic transformation was insufficient, almost can not guarantee the retained austenite in the final sheet metal product, for example martensitic phase of a large amount of hard phases occurred, so the upper limit is set to 10 ℃/sec..
When up to being lower than when tentatively cooling off under 650 ℃ the temperature, cooling period can produce pearlite, causes the C failure elements for stable austenite, finally can not obtain the retained austenite of sufficient quantity, so lower limit is set to 650 ℃.But when cooling is surpassing when ending under 710 ℃ the temperature, ferritic transformation is insufficient, has promoted the growth of grain boundary oxide layer, so ceiling temperature is set to 710 ℃.
In the quick cooling of the secondary cooling of successfully carrying out, cooling rate is not less than 0.1 ℃/sec. at least, preferably is not less than 1 ℃/sec., to such an extent as to during cooling, does not produce perlitic transformation, cementite precipitation and analog.
But because from the angle of capacity of equipment, the cooling rate that surpasses 100 ℃/sec. almost can not realize, so the scope of cooling rate is confirmed as from 0.1 to 100 ℃/sec., and preferred from 1.0 to 100 ℃/sec..
When the cooling termination temperature of secondary cooling is lower than bath temperature, operational issue appears, and when it surpassed bath temperature+50 to+100 ℃, carbide precipitated at short notice, so, can not guarantee retained austenite and the martensite of sufficient quantity.For these reasons, the cooling termination temperature of secondary cooling be set at from the zinc bath temperature to zinc bath temperature+50 to 100 ℃ scope.So, the stability of operation and guarantee to promote as much as possible the formation of bainite and the wettable that fully guarantees plating when guaranteeing that sheet metal transmits, preferably sheet metal is remained on and be no less than for 1 second in the said temperature, this time is included in the dip time in the plating bath.When the retention time is long, will affect badly output and produce carbide, so, the time except annealing needs, preferably will be limited in no more than 3000 seconds the retention time.
At room temperature for the stable austenite phase that is retained in the sheet metal, be essential by the concentration of carbon that changes mutually a part of austenite into Bainite Phases of Some and increase in the austenite.In order to promote the transformation of the bainite in the Alloying Treatment process, preferably in 300 to 550 ℃ temperature range, sheet metal is kept 1 to 3000 second, more preferably 15 seconds to 20 minutes.When temperature was lower than 300 ℃, the transformation of bainite occured hardly.But, when temperature surpasses 550 ℃, can form carbide, and lay in ample stocks of retained austenite and become mutually very difficult, so the upper limit is set to 550 ℃.
In order to form martensitic phase, do not need to occur bainite transformation, these are different with the situation that keeps the austenite phase.On the other hand, owing to working as in the situation that reservation austenite phase must suppress carbide and pearlite formation mutually, so after the secondary cooling, must fully carry out Alloying Treatment, and determine under 300 to 550 ℃ temperature, to carry out Alloying Treatment under preferred 400 to the 550 ℃ temperature.
For the amount that guarantees oxide in the interface in above-mentioned scope, the work course of preferably controlling temperature and beginning from the hot rolling stage.At first, expectation produces surface oxide layer as far as possible equably by control: the heating-up temperature of steel slab is 1150 to 1230 ℃; 1000 ℃ percent reduction is not less than 50%; Final temperature is not less than 850 ℃, preferably is not less than 880 ℃; Coiling temperature is not higher than 650 ℃, and stays at the same time elements such as Ti, Al.During Annealing suppresses the formation of Si oxide as much as possible in solid solution state.In addition, be desirably in final rolling after, come the oxide skin(coating) that forms during the as much as possible place to go hot rolling by high pressure descaling or a large amount of pickling.In addition, in order to weaken the generation of oxide, expectation uses diameter to be not more than the roller of 1000mm, controls cold rolling reduction ratio and is not less than 30%.Thereafter, when annealing, in order to pass through to suppress SiO
2Formation promote the formation of other oxide, expectation with the speed heating sheet metal of 5 ℃/sec. until reach and be not less than 750 ℃ temperature range.On the other hand, when very high or annealing time is very long when annealing temperature, produce a lot of oxides, and therefore cause machinability and fatigue resistance to worsen.So as definite (33) of the present invention, the maximum temperature that is desirably in annealing temperature is being not less than 0.1 * (Ac
3-Ac
1)+Ac
1(℃) to not being higher than Ac
3-30 (℃) temperature range in, control no more than 60 minutes of holdup time.
Embodiment
The below will explain the present invention in detail based on embodiment.
The example 1 of embodiment 1
The below will at length explain the present invention based on the embodiment 1 of embodiment 1.
The sheet metal that will have chemical composition shown in the table 1 is heated to 1200 ℃ temperature; Be not less than Ar
3Finish the hot rolling of steel under the temperature of transition temperature; Then cooling hot-rolled sheet metal batches sheet metal under the temperature that is not less than the bainite start point temperature, this temperature is determined by the chemical composition of every kind of steel; Then pickling, with the thickness of the cold rolling one-tenth of cold-rolled steel 1.0mm.
The back will mention that the trade mark is that sheet metal reduction ratio up to 1000 ℃ time of M-1, N-1, O-1, P-1 and Q-1 is 70%, final temperature is that 900 ℃ and coiling temperature are to carry out hot rolling under 700 ℃ the condition, and use diameter to carry out cold rolling as the roller of 800mm, reduction ratio with 50%.The reduction ratio of other steel up to 1000 ℃ the time is 70%, final temperature is that 900 ℃ and coiling temperature are to carry out hot rolling under 600 ℃ the condition, and uses diameter to carry out cold rolling as 1200mm roller, reduction ratio with 50%.
After this, Ac
1Transition temperature and Ac
3Transition temperature can according to the composition (with quality %) of every kind of steel, calculate according to following formula:
Ac
1＝723-10.7×Mn％+29.1×Si％，
Ac
3＝910-203×(C％)
1/2+44.7×Si％+31.5×Mo％-30×Mn％-11×Cr％+400×Al％。
Sheet metal carries out plating according to following condition: the speed with 5 ℃/sec. heats sheet metal until reach by Ac
1Transition temperature and Ac
3The annealing temperature calculated of transition temperature, and hold them in and contain 10%H
2N
2In the gas; Then, the cooldown rate with 0.1 to 10 ℃/sec. is cooled to 600 to 700 ℃ with them; Cooldown rate with 1 to 20 ℃/sec. is cooled to bath temperature continuously with them; They are immersed in 460 ℃ the zinc plating bath reached for 3 seconds, wherein, solution composition changes.
In addition, when carrying out the Fe-Zn Alloying Treatment, be adjusted in mass 5-20% with some sheet metal plating and with the Fe content in the coating, then in 300 to 550 ℃ temperature range, kept 15 seconds to 20 minutes.Observe the area of the coalescent state of the upper dregs in surface and measurement plating leakage part by vision and assess plating performance.By coating being dissolved in 5% the hydrochloric acid solution that contains corrosion inhibiter and this solution being carried out chemical analysis determine Coating composition.
Intercepting is used for carrying out the JIS#5 sample (reduction ratio with 0.5 to 2.0% is rolled at the skin-pass line) of tension test and measuring its mechanical performance from the plating sheet metal.In addition, by in the plain bending fatigue test, apply the pressure that is equivalent to 50% hot strength and relatively assess rupture life.In addition, by the assessment of salt spray test repeatedly corrosion resisting property.
As shown in table 2, in steel of the present invention, the degree of depth of grain boundary oxide layer is very shallow, and under the pressure that is equivalent to 50% hot strength, surpass 10 fatigue life
6Individual bend cycles.In addition, well balance intensity and ductility, do not observe the rust product, even after test, keep good appearance yet.
Table 3-1 (continuing): the plating performance of various steel
| The code of steel-processing numbering | The content % of Al in the coating | The content % of Mn in the coating | The content % of Fe in the coating | The calculated value of formula (1) | Other element % in the coating |
| C-1 | 1 | 1 | 15 | 1.77 | |
| C-2 | 0.5 | 0.01 | 7 | -4.35 | |
| E-1 | 0.05 | 0.5 | 12 | 7.76 | |
| E-1-1 | 0.17 | 0.04 | 9 | 0.51 | Si：0.02 |
| E-1-2 | 0.18 | 0.03 | 9 | 0.26 | Y：0.02， Nd：0.04 |
| E-1-3 | 0.17 | 0.03 | 9 | 0.38 | La：0.02 |
| E-1-4 | 0.15 | 0.02 | 9 | 0.51 | B：0.005 |
| E-1-5 | 0.2 | 0.08 | 9 | 0.63 | Rb：0.02 |
| E-2 | 0.25 | 0.01 | 8 | -0.87 | |
| G-1 | 0.3 | 0.3 | 11 | 2.05 | |
| G-2 | 0.2 | 0.01 | 8 | -0.33 | |
| H-1 | 0.5 | 0.5 | 7 | 1.26 | |
| I-1-1 | 0.1 | 0.05 | 7 | 0.63 | Cs：0.04 |
[0315]Table 3-2 (continuing): the plating performance of various steel
| The code of steel-processing numbering | The content % of Al in the coating | The content % of Mn in the coating | The content % of Fe in the coating | The calculated value of formula (1) | Other element % in the coating |
| I-1-2 | 0.15 | 0.1 | 8 | 0.63 | K：0.02， Ni：0.05 |
| I-1-3 | 0.14 | 0.1 | 7 | 0.76 | Ag：0.01， Co：0.01 |
| I-1-4 | 0.3 | 0.25 | 8 | 0.63 | Ni：0.02， Cu：0.03 |
| I-1-5 | 0.35 | 0.27 | 9 | 0.26 | Na：0.02， Cr：0.01 |
| I-2 | 0.5 | 0.1 | -3.74 | ||
| J-1 | 1 | 1 | 0.24 | ||
| J-2 | 1 | 1 | 8 | 0.24 | |
| J-3 | 0.5 | 0 | 4 | -6.02 | |
| K-1-1 | 1 | 0.9 | 0.69 | Be：0.005 | |
| K-1-2 | 0.8 | 0.7 | 0.69 | Ti：0.01， In：0.01 |
[0317]Table 3-3 (continuing): the plating performance of various steel
| The code of steel-processing numbering | The content % of Al in the coating | The content % of Mn in the coating | The content % of Fe in the coating | The calculated value of formula (1) | Other element % in the coating |
| K-1-3 | 0.9 | 0.8 | 0.69 | Cd：0.02 | |
| K-2-1 | 0.9 | 0.8 | 9 | 0.69 | Pb：0.03 |
| K-2-2 | 1 | 0.95 | 8 | 1.32 | To：0.02 |
| K-2-3 | 1 | 0.9 | 8 | 0.69 | W：0.02， Hf：0.02 |
| L-1-1 | 0.3 | 0.15 | 10 | 0.60 | Mo：0.01 |
| L-1-2 | 0.25 | 0.14 | 10 | 1.10 | Zr：0.01， Ti：0.01 |
| L-1-3 | 0.3 | 0.2 | 9 | 1.23 | Ge：0.01 |
| L-1-4 | 0.3 | 0.15 | 11 | 0.60 | Ta：0.01， V：0.01 |
| M-1 | 0.3 | 0.4 | 11 | 3.73 | |
| N-1 | 0.4 | 0.3 | 11 | 1.23 | |
| O-1 | 0.5 | 0.5 | 12 | 2.48 | |
| P-1 | 0.1 | 0.3 | 11 | 4.98 | |
| Q-1 | 0.15 | 0.2 | 10 | 3.10 |
[0319]Table 3-4 (continuing): the plating performance of various steel
| The appearance of plating leakage defective | The outward appearance after the salt spray test repeatedly | Remarks |
| No | Non-corrosive | Steel of the present invention |
| Have | Get rusty | Comparative steel |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| Have | Get rusty | Comparative steel |
| No | Non-corrosive | Steel of the present invention |
| Have | Get rusty | Comparative steel |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
[0321]Table 3-5 (continuing): the plating performance of various steel
| The appearance of plating leakage defective | The outward appearance after the salt spray test repeatedly | Remarks |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| Have | Get rusty | Comparative steel |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| Have | Get rusty | Comparative steel |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
[0323]Table 3-6 (continuing): the plating performance of various steel
| The appearance of plating leakage defective | The outward appearance after the salt spray test repeatedly | Remarks |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
| No | Non-corrosive | Steel of the present invention |
Surplus element in (remarks) coating is zinc.
The numeral of underscoring is situation about dropping on outside the scope of the invention.
As can be understood from Table 3, even in the situation that contain relatively large Si in the sheet metal, in sheet metal of the present invention, by control coating and steel-sheet composition, also can make sheet metal not form the plating leakage defective and have good corrosion resistance.
In addition, be appreciated that when containing the 4th kind of element (in the table 3 " other element in the coating ") in the coating, even in the very little situation of the definite value in the left side of formula 1, plating performance is also fine.
Table 4 has shown the impact of preparation condition.In the situation that the steel-sheet working condition does not satisfy described requirement, even its composition in described scope, also can make the degree of depth of grain boundary oxide layer become large, thereby shortened fatigue life.In addition, be appreciated that conversely it namely is to satisfy described requirement at working condition, in the situation that the sheet metal composition departs from described scope, also can make fatigue life also very short.
Table 5 has shown the impact of oxide form.In sheet metal of the present invention, do not form rust and fatigue strength and surpass 2 * 10
6Individual bend cycles is so sheet metal has good material quality.
The example 1 of embodiment 2
The below will at length explain the present invention based on the embodiment 1 of embodiment 2.
The sheet metal that will have chemical composition as shown in table 6 is heated to 1200 ℃ temperature; Be not less than Ar
3Finish the hot rolling of steel under the temperature of transition temperature; With hot rolled steel sheet cooling, then sheet metal to be batched being not less than under the temperature of bainite start point, this temperature is determined by the chemical composition of every kind of steel; Then pickling is with the cold rolling one-tenth thickness of this sheet metal cold-reduced sheet that is 1.0mm.
After this, Ac
1Transition temperature and Ac
3Transition temperature with the composition (with quality %) of every kind of steel, calculate according to following formula:
Ac
1＝723-10.7×Mn％-16.9×Ni％+29.1×Si％+16.9×Cr％，
Ac
3＝910-203×(C％)
1/2+15.2×Ni％+44.7×Si％+104×V％+31.5×Mo％-30×Mn％-11×Cr％-20×Cu％+700×P％+400×Al％+400×Ti％。
This sheet metal carries out plating by following step: sheet metal is heated to by Ac
1Transition temperature and Ac
3The annealing temperature calculated of transition temperature, and hold them in and contain 10%H
2N
2In the gas; Then, the cooldown rate with 0.1 to 10 ℃/sec. is cooled to 680 ℃ with them; Cooldown rate with 1 to 20 ℃/sec. is cooled to bath temperature continuously with them; They are immersed in 460 ℃ the zinc plating bath reached for 3 seconds, wherein, solution composition changes.
In addition, when carrying out the Fe-Zn Alloying Treatment, some sheet metals kept 15 seconds to 20 minutes in 300 to 550 ℃ temperature range after zinc-plated, and the Fe content in the coating is adjusted to 5 to 20% in mass.Observe the area of the coalescent state of the upper dregs in surface and measurement plating leakage part by vision and assess plating performance.By coating being dissolved in 5% the hydrochloric acid solution that contains corrosion inhibiter and this solution being carried out chemical analysis determine Coating composition.
Intercepting is used for carrying out the JIS#5 sample (reduction ratio with 0.5 to 2.0% is rolled at the skin-pass line) of tension test and measuring its mechanical performance from the plating sheet metal.Then, after applying 20% stretcher strain, by sheet metal is applied 60 ° of bendings and backward bending forming assess the adhesion of coating behind the severe deformation.Undertaken crooked and the part behind the bending forming and it is peeled off the relative adhesion of assessing coating backward by the polyethylene insulation band is attached to, then measure in the per unit length ratio of the length that comes off.Preparation condition is shown in Table 8.
As shown in table 7, at sheet metal of the present invention, that is, and D1 to D8 (Nos.1,2,5 to 8,10 to 14) in the situation, do not observe the plating leakage defective, well balance intensity and ductility, even and after applying 20% stretcher strain, apply crooked and bending forming backward to sheet metal, the ratio that comes off of coating also is low to moderate and is no more than 1%.On the other hand, in comparative steel, that is, and in the situation of C1 to C5 (numbering 17 to 21), in order to prepare test specimen, crack in a large number during the hot rolling and productivity ratio very low.After the hot rolled steel sheet that obtains by polishing was removed crackle, then cold rolling the and annealing with this hot rolled steel sheet be used as the quality of materials test.But the adhesiveness of some sheet metals (C2 and C4) after fierce operation is very poor or be unable to bear 20% shaping.
As shown in table 8, in the numbering 3,9,19 and 21 that does not satisfy formula 1, the deterioration of coating wettable and the binding force of cladding material behind severe deformation are very poor.In to the unsafty situation of steel-sheet microstructure modification, the plating adhesion after the fierce operation is also very poor.
In the situation that numbering 4, because the secondary cooldown rate is very slow, thus austenite and martensite do not produced, but the generation pearlite in generation and the plating adhesion after the fierce operation are very poor.
The embodiment 1 of embodiment 3
The below will at length explain the present invention based on the embodiment 1 of embodiment 3.
The sheet metal that will have chemical composition shown in the table 9 is heated to 1200 ℃ temperature; Be not less than Ar
3Finish the hot rolling of steel under the temperature of transition point; With hot rolled steel sheet cooling, then batch sheet metal being not less than under the temperature of bainite start point, this temperature is determined by the chemical composition of every kind of steel; Then pickling, with the cold rolling one-tenth thickness of this sheet metal cold-reduced sheet that is 1.0mm.
After this, Ac
1Transition temperature and Ac
3Transition temperature according to the composition (with quality %) of every kind of steel, calculate according to following formula:
Ac
1＝723-10.7×Mn％+29.1×Si％，
Ac
3＝910-203×(C％)
1/2+44.7×Si％+31.5×Mo％-30×Mn％-11×Cr％+400×Al％。
This sheet metal carries out plating by following step: sheet metal is heated to by Ac
1Transition temperature and Ac
3The annealing temperature calculated of transition temperature, and hold them in and contain 10%H
2N
2In the gas; Then, the cooldown rate with 0.1 to 10 ℃/sec. is cooled to 680 ℃ with them; Cooldown rate with 1 to 20 ℃/sec. is cooled to bath temperature continuously with them; They are immersed in 460 ℃ the zinc plating bath reached for 3 seconds, wherein, solution composition changes.
In addition, when carrying out the Fe-Zn Alloying Treatment, some sheet metals kept 15 seconds to 20 minutes in 300 to 550 ℃ temperature range after zinc-plated, and the Fe content in the coating is adjusted to 5 to 20% in mass.Observe the area of the coalescent state of the upper dregs in surface and measurement plating leakage part by vision and assess plating performance.By coating being dissolved in 5% the hydrochloric acid solution that contains corrosion inhibiter and this solution being carried out chemical analysis determine Coating composition.
Intercepting is used for carrying out the JIS#5 sample (reduction ratio with 0.5 to 2.0% is rolled at the skin-pass line) of tension test and measuring its mechanical performance from galvanized sheet metal.Then, after applying 20% stretcher strain, by sheet metal is applied 60 ° of bendings and backward bending forming assess the adhesion of coating behind the severe deformation.Undertaken crooked and the sweep behind the bending forming and it is peeled off the relative adhesion of assessing coating backward by the polyethylene insulation band is attached to, then measure in the length that per unit length comes off the ratio of the length that comes off.Preparation condition is shown in Table 11.
As shown in table 10, at sheet metal of the present invention, namely, D1 to D12 (Nos.1,2,5,12,13,20,22 to 24,32,34 to 36,39 and 42) in the situation, do not observe the plating leakage defective, well balance intensity and ductility, even and after applying 20% stretcher strain, apply crooked and bending forming backward to sheet metal, the ratio that comes off of coating also is low to moderate and is no more than 1%.In addition, be appreciated that when containing other element as shown in table 10 in the coating, even in the situation that less by the determined value in formula 1 left side, plating performance is also fine.
On the other hand, in comparative steel, that is, and in the situation of C1 to C5 (numbering 44 to 48), in order to prepare test specimen, crack in a large number during the hot rolling and productivity ratio very low.After the hot rolled steel sheet that obtains by polishing was removed crackle, then cold rolling the and annealing with this hot rolled steel sheet be used as the quality of materials test.But the adhesiveness of some sheet metals (C2 and C4) after fierce operation is very poor or be unable to bear 20% shaping.
As shown in table 10, in the numbering 3,21,46 and 48 that does not satisfy formula 1, the deterioration of coating wetability and the adhesiveness after fierce operation are very poor.In to the unsafty situation of steel-sheet microstructure modification, the plating adhesion after severe deformation is also very poor.
In the situation that No.3, because the secondary cooldown rate is very slow, thus austenite and martensite do not produced, but generation pearlite and the plating adhesion after severe deformation in generation are very poor.
The embodiment of embodiment 2
The below will at length explain the present invention based on the embodiment of embodiment 2.
The sheet metal that will have chemical composition as shown in table 12 is heated to 1180 to 1250 ℃ temperature; Under 880 to 1100 ℃, finish the hot rolling of steel; With hot rolled steel sheet cooling, then batch sheet metal being not less than under the temperature of bainite start point, this temperature is determined by the chemical composition of every kind of steel; Then pickling is with the cold rolling one-tenth thickness of this sheet metal cold-reduced sheet that is 1.0mm.
After this, Ac
1Transition temperature and Ac
3The composition (with quality %) of every kind of steel of transition temperature root a tree name, calculate according to following formula:
Ac
1＝723-10.7×Mn％+29.1×Si％，
Ac
3＝910-203×(C％)
1/2+44.7×Si％+31.5×Mo％-30×Mn％-11×Cr％+400×Al％。
This sheet metal carries out plating by following step: sheet metal is heated to by Ac
1Transition temperature and Ac
3The annealing temperature calculated of transition temperature, and they be retained in contain 10%H
2N
2In the gas; Then, the cooldown rate with 0.1 to 10 ℃/sec. is cooled to 650 to 700 ℃ temperature range with them; Cooldown rate with 0.1 to 20 ℃/sec. is cooled to bath temperature continuously with them; They are immersed in 460 to 470 ℃ the zinc plating bath reached for 3 seconds, wherein, solution composition changes, and the reduction ratio with 0.5 to 2.0% is rolled at the skin-pass line.
In addition, when carrying out the Fe-Zn Alloying Treatment, some sheet metals kept 15 seconds to 20 minutes in 400 to 550 ℃ temperature range behind plating, and the Fe content in the coating is adjusted to 5 to 20% in mass.Observe the area of the coalescent state of the upper dregs in surface and measurement plating leakage part by vision and assess plating performance.By coating being dissolved in 5% the hydrochloric acid solution that contains corrosion inhibiter and this solution being carried out chemical analysis determine Coating composition, the results are shown in the table 13.
In the table 13 and 14, the evaluation grade of all outward appearances that satisfies the steel of formula (2) among the present invention all is 5, well balance intensity and ductility.On the other hand, the comparative steel of discontented unabridged version invention prescribed limit, its outward appearance evaluation grade is low without any exception, the balanced differences of intensity and ductility.In addition, be produced the steel that drops in the claim prescribed limit of the present invention, its microscopic structure is comprised of above-mentioned tissue, and the balance between the outward appearance of steel and intensity and the ductility is good.
Table 13-1-1: coating wetability, corrosion resistance, microscopic structure and the fatigue life of various steel.
| The code of steel | Process numbering | Mn content in the coating, % | Al content in the coating, % | Mo content in the coating, % | Fe content in the coating, % | (1) value of calculating by formula |
| A | 1 | 0.01 | 0.1 | 0.0001 | 0.43 | |
| A | 2 | 0.05 | 0.15 | 0.001 | 12 | 0.38 |
| A | 3 | 0.04 | 0.6 | 0.001 | 11 | -0.07 |
| B | 4 | 0.03 | 0.3 | 0.001 | 0.141 | |
| B | 5 | 0.11 | 0.4 | 0.002 | 10 | 0.041 |
| B | 6 | 0.04 | 0.4 | ＜0.0001 | 0.041 | |
| C | 7 | 0.1 | 0.3 | 0.002 | 12 | 0.245 |
| C | 8 | 0.04 | 0.8 | 0.003 | 11 | -0.26 |
| D | 9 | 0.7 | 0.5 | ＜0.0001 | 0.051 | |
| D | 10 | 0.6 | 0.4 | 0.002 | 10 | 0.151 |
| E | 11 | 0.2 | 0.3 | 0.005 | 11 | 0.205 |
| E | 12 | 0.15 | 0.4 | 0.002 | 10 | 0.105 |
| E | 13 | 0.3 | 0.3 | 0.005 | 10 | 0.205 |
| F | 14 | 0.5 | 0.45 | 0.001 | 0.046 | |
| F | 15 | 0.1 | 0.05 | 0.003 | 9 | 0.446 |
[0425]Table 13-1-2 (continuing): coating wetability, corrosion resistance, microscopic structure and the fatigue life of various steel.
| The code of steel | Process numbering | Mn content in the coating, % | Al content in the coating, % | Mo content in the coating, % | Fe content in the coating, % | (1) value of calculating by formula |
| G | 16 | 1 | 0.5 | 0.002 | 10 | 0.025 |
| G | 17 | 1 | 0.4 | 0.002 | 10 | 0.125 |
| H | 18 | 0.5 | 0.7 | 0.0003 | -0.19 | |
| H | 19 | 0.4 | 0.35 | 0.0002 | 10 | 0.165 |
| H | 20 | 0.5 | 0.45 | 0.0002 | 9 | 0.065 |
| I | 21 | 0.7 | 0.1 | 0.001 | 11 | 0.442 |
| I | 22 | 0.7 | 0.5 | 0.003 | 12 | 0.042 |
| I | 23 | 1 | 0.4 | 0.002 | 12 | 0.142 |
| I | 24 | 0.05 | 0.45 | 0.004 | 11 | 0.092 |
| I | 25 | 0.5 | 0.3 | 0.007 | 12 | 0.242 |
| I | 26 | 0.5 | 0.35 | 0.001 | 0.192 | |
| I | 27 | 0.6 | 0.13 | ＜0.0001 | 0.412 | |
| J | 28 | 0.05 | 0.34 | 0.0002 | 11 | 0.118 |
[0427]
Table 13-1-4 (continuing): the fatigue life of the coating profit warm nature of various steel, corrosion resistance, microscopic structure.
| Other elements in the coating, % | Behind plating, whether apply alloying heat treatment | The outward appearance evaluation grade | |
| No | 5 | Steel of the present invention | |
| Be | 5 | Steel of the present invention | |
| Be | 3 | Comparative steel | |
| No | 5 | Steel of the present invention | |
| Si：0.001 | Be | 5 | Steel of the present invention |
| No | 3 | Comparative steel | |
| Be | 5 | Steel of the present invention | |
| Be | 2 | Comparative steel | |
| Cr：0.004， W：0.005 | No | 3 | Comparative steel |
| Cr：0.005， W：0.007 | Be | 5 | Steel of the present invention |
| K：0.01 | Be | 5 | Steel of the present invention |
| Ag：0.004 | Be | 5 | Steel of the present invention |
| Ni：0.01， Cu：0.01， Co：0.002 | Be | 5 | Steel of the present invention |
| Ti：0.002， Cs：0.003 | No | 5 | Steel of the present invention |
| Rb：0.002 | Be | 5 | Steel of the present invention |
[0430]Table 13-1-5 (continuing): coating wetability, corrosion resistance, microscopic structure and the fatigue life of various steel.
| Other elements in the coating, % | Behind plating, whether apply alloying heat treatment | The outward appearance evaluation grade | |
| V：0.003， Zr：0.003， Hf：0.002， Ta：0.002 | Be | 5 | Steel of the present invention |
| V：0.002， Zr：0.002， Nd：0.007 | Be | 5 | Steel of the present invention |
| B：0.002， Y：0.003 | No | 3 | Comparative steel |
| B：0.003， Y：0.002 | Be | 5 | Steel of the present invention |
| Na：0.007 | Be | 5 | Steel of the present invention |
| Cd：0.01 | Be | 5 | Steel of the present invention |
| La：0.02 | Be | 5 | Steel of the present invention |
| Tl：0.02 | Be | 5 | Steel of the present invention |
| In：0.005 | Be | 5 | Steel of the present invention |
| Be：0.01 | Be | 5 | Steel of the present invention |
| Pb：0.02 | No | 5 | Steel of the present invention |
| No | 4 | Comparative steel | |
| No | 5 | Steel of the present invention |
[0432]
The embodiment of embodiment 3
The below will at length explain the present invention based on the embodiment of embodiment 3.
The sheet metal that will have chemical composition as shown in Table 15 is heated to 1200 to 1250 ℃ temperature; Be not less than under 1000 ℃ the temperature, to be not less than 60% total reduction with the steel roughing of heating; Then finish the steel-sheet hot rolling; With the cooling of this hot rolled steel sheet, then batch this sheet metal under the temperature of bainite start point being not less than, this temperature is determined by the chemical composition of every kind of steel; Then pickling, with the cold rolling one-tenth thickness of this sheet metal cold-reduced sheet that is 1.0mm.
After this, Ac
1Transition temperature and Ac
3Transition temperature according to the composition (with quality %) of every kind of steel, calculate according to following formula:
Ac
1＝723-10.7×Mn％+29.1×Si％，
Ac
3＝910-203×(C％)
1/2+44.7×Si％+31.5×Mo％-30×Mn％-11×Cr％+400×Al％。
This sheet metal carries out plating by following step: sheet metal is heated to by Ac
1Transition temperature and Ac
3The annealing temperature calculated of transition temperature, and hold them in and contain 10%H
2N
2In the gas; When the highest obtainable temperature of During Annealing be defined as Tmax (℃) time, with the cooldown rate of Tmax/1000 to Tmax/10 ℃/sec., in Tmax-200 ℃ to Tmax-100 ℃ temperature range, cool off after the annealing; Then, with the cooldown rate of 0.1 to 100 ℃/sec., cool off to the temperature range of bath temperature+50 ℃ at bath temperature-30 ℃; Then, they are immersed in the plating bath; Kept 2 to 200 seconds to the temperature range of bath temperature+50 ℃ at bath temperature-30 ℃, this time comprises dip time.When carrying out Fe-Zn Alloying Treatment, some sheet metals plating after, 400 to 550 ℃ temperature range in kept 15 second to 20 minute, and Fe content in coating in mass be adjusted to 5 to 20% thereafter.In addition, be rolled at the skin-pass line with 0.5 to 2.0% reduction ratio.Sheet metal is carried out sufficient flat wise bend (R=1t), as the corrosion proof mode of assessment, in containing the environment of chlorine, carry out up to the cycle corrosion test of 150 JASO circulations and the progress of evaluation of corrosion.By coating being dissolved in 5% the hydrochloric acid solution that contains corrosion inhibiter and this solution being carried out chemical analysis determine Coating composition, the results are shown in the table 16.
In the table 16 and 17, all Corrosion Evaluation grades that satisfy the steel of formula (3) among the present invention all are 4 or 5, well balance intensity and ductility.
On the other hand, the comparative steel of discontented unabridged version invention prescribed limit is because it can not satisfy microscopic structure or to the control of preparation condition, the balance between its intensity and ductility is poor without any exception.The Corrosion Evaluation grade of comparative steel numbering 3,13 and 20 is 4 or 5.But, numbering 13 and 20, the balance between its intensity and ductility is very poor, and the tensile strength of numbering 3 is very low.In addition, what make drops on steel in the claim prescribed limit of the present invention, and its microscopic structure is comprised of above-mentioned tissue, and the balance between the outward appearance of steel and intensity and the ductility is good.
Industrial applicibility
The invention provides: a kind of sheet metal with high strength, high ductibility galvanizing by dipping sheet metal and dip galvanized DIFFUSION TREATMENT of high antifatigue and highly corrosion resistant; Binding force of cladding material after a kind of high-strength hot-dip galvanized sheet metal of ductility excellence, this sheet metal can improve the plating leakage defective and improve severe deformation, and preparation method thereof; A kind of high-strength high-tractility galvanizing by dipping sheet metal with high antifatigue and highly corrosion resistant; The high-strength hot-dip galvanized sheet metal of a kind of outward appearance and additivity excellence, this sheet metal can suppress the generation of plating leakage defective, and preparation method thereof; A kind of high strength, through sheet metal and a kind of high-strength hot-dip galvanized sheet metal of dip galvanized DIFFUSION TREATMENT, this sheet metal can suppress plating leakage defective, blemish and have corrosion resistance, the corrosion resistance in containing the environment of chlorion particularly, have again simultaneously high ductibility, with and preparation method thereof.
Claims (9)
1. high-strength hot-dip galvanized sheet metal with high binding force of cladding material and ductility behind the severe deformation, described galvanizing by dipping sheet metal has one deck coating, and in mass, coating contains,
Al:0.001～0.5%, and
Mn：0.001～2％，
Surplus is zinc and inevitable impurity, and in mass, surface of thin steel sheet is comprised of following compositions,
C：0.0001～0.3％，
Si：0.01～2.5％，
Mn：0.01～3％，
Al:0.001～4%, and
Surplus is iron and inevitable impurity, it is characterized in that, Si content in the sheet metal: X (quality %), Al content: A (quality %) and Mn content: B (quality %) satisfy following formula 1 in Mn content: Y (quality %) and Al content: Z (quality %) and the coating;
In the sheet metal microscopic structure by volume, have and comprise 70% to 97% ferritic principal phase, and the average grain size of principal phase is not more than 20 μ m, and by volume, contains 3% to 30% austenite and/or the average grain size of martensitic second-phase and second-phase and is not more than 10 μ m;
And the steel-sheet second-phase is comprised of austenite; And C content: C (quality %) and Mn content: Mn (quality %) and austenitic percent by volume: V in the steel
γThe percent by volume of (with %) and ferrite and bainite: V
α(with %) satisfies following formula 2:
3-(X+Y/10+Z/3)-12.5×(A-B)≥0 ... 1
(V
γ+V
α)/V
γ×C+Mn/8≥2.0 ... 2。
2. sheet metal with high-strength hot-dip galvanized layer DIFFUSION TREATMENT of high binding force of cladding material and ductility behind the severe deformation, the sheet metal of described dip galvanized DIFFUSION TREATMENT has one deck coating, and in mass, coating contains,
Al：0.001～0.5％，
Mn：0.001～2％，
And Fe:5～20%
Surplus is zinc and inevitable impurity, and in mass, surface of thin steel sheet is comprised of following compositions,
C：0.0001～0.3％，
Si：0.01～2.5％，
Mn：0.01～3％，
Al:0.001～4%, and
Surplus is iron and inevitable impurity, it is characterized in that, Si content in the sheet metal: X (quality %), Al content: A (quality %) and Mn content: B (quality %) satisfy following formula 1 in Mn content: Y (quality %) and Al content: Z (quality %) and the coating; And
In the sheet metal microscopic structure by volume, have and comprise 70% to 97% ferritic principal phase, and the average grain size of principal phase is not more than 20 μ m, and by volume, contains 3% to 30% austenite and/or the average grain size of martensitic second-phase and second-phase and is not more than 10 μ m;
And the steel-sheet second-phase is comprised of austenite; And C content: C (quality %) and Mn content: Mn (quality %) in steel, and austenitic percent by volume: V
γThe percent by volume of (with %) and ferrite and bainite: V
α(with %) satisfies following formula 2:
3-(X+Y/10+Z/3)-12.5×(A-B)≥0 ... 1
(V
γ+V
α)/V
γ×C+Mn/8≥2.000 ... 2。
3. described in claim 1 or 2, have high binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility or a sheet metal of dip galvanized DIFFUSION TREATMENT behind the severe deformation, it is characterized in that, the austenite of formation sheet metal second-phase and/or martensitic average grain size are 0.01 to 0.7 times of ferrite average grain size.
4. as claimed in claim 1 or 2 have binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility or a sheet metal of dip galvanized DIFFUSION TREATMENT behind the severe deformation, it is characterized in that, the steel-sheet microscopic structure has and comprises 50% (volume) to the average grain size of the ferritic principal phase of 95% (volume) and principal phase and be not more than 20 μ m, and comprise 3% (volume) to the average grain size of 30% (volume) austenite and/or martensitic second-phase and second-phase and be not more than 10 μ m, also contain simultaneously 2% (volume) to the bainite of 47% (volume).
5. as claimed in claim 1 or 2 have high binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility or a sheet metal of dip galvanized DIFFUSION TREATMENT behind the severe deformation, it is characterized in that, also contain 0.001% (quality) in the described steel to the Mo of 5% (quality).
6. as claimed in claim 1 or 2 have high binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility or a sheet metal of dip galvanized DIFFUSION TREATMENT behind the severe deformation, it is characterized in that, also contain 0.0001% (quality) in the described steel to the S of the P and 0.0001% (quality) to 0.01% (quality) of 0.1% (quality).
7. as claimed in claim 1 or 2 have high binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility or a sheet metal of dip galvanized DIFFUSION TREATMENT behind the severe deformation, it is characterized in that, in mass, coating also contains:
Ca：0.001～0.1％，
Mg：0.001～3％，
Si：0.001～0.1％，
Mo：0.001～0.1％，
W：0.001～0.1％，
Zr：0.001～0.1％，
Cs：0.001～0.1％，
Rb：0.001～0.1％，
K：0.001～0.1％，
Ag：0.001～5％，
Na：0.001～0.05％，
Cd：0.001～3％，
Cu：0.001～3％，
Ni：0.001～0.5％，
Co：0.001～1％，
La：0.001～0.1％，
Tl：0.001～8％，
Nd：0.001～0.1％，
Y：0.001～0.1％，
In：0.001～5％，
Be：0.001～0.1％，
Cr：0.001～0.05％，
Pb：0.001～1％，
Hf：0.001～0.1％，
Tc：0.001～0.1％，
Ti：0.001～0.1％，
Ge：0.001～5％，
Ta：0.001～0.1％，
V:0.001～0.2%, and
B：0.001～0.1％
In one or more.
8. one kind for the preparation of having high binding force of cladding material and the high-strength hot-dip galvanized sheet metal of ductility or the steel-sheet method of dip galvanized DIFFUSION TREATMENT behind the severe deformation, it is characterized in that, to comprise the steel casting of any one described chemical composition in the claim 1 to 7, after casting, cool off bloom slab; And then heat above-mentioned bloom slab; Then bloom slab is rolled into hot rolled steel sheet and it is batched, then pickling and cold rolling above-mentioned hot rolled steel sheet; Then, be not less than 0.1 * (Ac
3-Ac
1)+Ac
1(℃) to not being higher than Ac
3+ 50 (℃) temperature range in, with above-mentioned cold-reduced sheet annealing 10 seconds to 30 minutes; Then with the cooldown rate of 0.1～10 ℃/sec, above-mentioned sheet metal is cooled to 650 to 700 ℃ temperature range; Then, with the cooldown rate of 1～100 ℃/sec, above-mentioned sheet metal is cooled to bath temperature to the temperature range of bath temperature+100 ℃; Sheet metal is remained on the zinc bath temperature reach 1 to 3000 second to the temperature range of zinc bath temperature+100 ℃, the above-mentioned time comprises dip time subsequently; Sheet metal is immersed in the zinc plating bath; Afterwards, above-mentioned sheet metal is cooled to room temperature.
9. method as claimed in claim 8 is characterized in that, after sheet metal being immersed in the zinc plating bath, carries out Alloying Treatment at 300 to 550 ℃, then sheet metal is cooled to room temperature.
Applications Claiming Priority (14)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP170857/2001 | 2001-06-06 | ||
| JP2001170857 | 2001-06-06 | ||
| JP2001211942 | 2001-07-12 | ||
| JP211942/2001 | 2001-07-12 | ||
| JP304037/2001 | 2001-09-28 | ||
| JP304035/2001 | 2001-09-28 | ||
| JP2001304034A JP3898923B2 (en) | 2001-06-06 | 2001-09-28 | High-strength hot-dip Zn-plated steel sheet excellent in plating adhesion and ductility during high processing and method for producing the same |
| JP2001304035 | 2001-09-28 | ||
| JP304036/2001 | 2001-09-28 | ||
| JP304034/2001 | 2001-09-28 | ||
| JP2001304037A JP3898925B2 (en) | 2001-09-28 | 2001-09-28 | High strength and high ductility hot dip galvanized steel sheet excellent in corrosion resistance and method for producing the same |
| JP2001304036A JP3898924B2 (en) | 2001-09-28 | 2001-09-28 | High-strength hot-dip galvanized steel sheet excellent in appearance and workability and its manufacturing method |
| JP131643/2002 | 2002-05-07 | ||
| JP2002131643A JP4331915B2 (en) | 2001-07-12 | 2002-05-07 | High strength and high ductility hot dip galvanized steel sheet excellent in fatigue durability and corrosion resistance and method for producing the same |
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| CNB028115236A Division CN100562601C (en) | 2001-06-06 | 2002-06-06 | Have the high-strength hot-dip galvanized steel sheet of high binding force of cladding material behind fatigue resistance, erosion resistance, ductility and the severe deformation and the steel sheet and the manufacture method thereof of galvanizing layer DIFFUSION TREATMENT |
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Families Citing this family (19)
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| MX2022004360A (en) * | 2019-10-11 | 2022-05-03 | Jfe Steel Corp | High-strength steel sheet, shock-absorbing member, and method for producing high-strength steel sheet. |
| US20240052449A1 (en) * | 2019-10-11 | 2024-02-15 | Jfe Steel Corporation | High strength steel sheet, impact absorbing member, and method for manufacturing high strength steel sheet |
| CN113249649B (en) * | 2021-04-16 | 2022-10-21 | 首钢集团有限公司 | Cold-rolled high-strength steel with good coating quality and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5019186A (en) * | 1989-06-23 | 1991-05-28 | Kawasaki Steel Corporation | Process for producing chromium-containing steel sheet hot-dip plated with aluminum |
| CN1226288A (en) * | 1996-05-31 | 1999-08-18 | 川崎制铁株式会社 | Plated steel plate |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2259920A (en) * | 1991-09-10 | 1993-03-31 | Gibson Chem Ltd | Surface conversion coating solution based on molybdenum and phosphate compounds |
| BR9305923A (en) * | 1992-02-22 | 1997-08-26 | Hoechst Ag | Electrochemical process for the preparation of glyoxalic acid |
| CN1041641C (en) * | 1993-06-29 | 1999-01-13 | 日本钢管株式会社 | Surface treated steel sheet and method therefor |
| US6004507A (en) * | 1997-08-11 | 1999-12-21 | Alphatech, Inc. | Material formulation for galvanizing equipment submerged in molten and aluminum zinc melts |
| US6410163B1 (en) * | 1998-09-29 | 2002-06-25 | Kawasaki Steel Corporation | High strength thin steel sheet, high strength alloyed hot-dip zinc-coated steel sheet, and method for producing them |
-
2002
- 2002-06-06 CN CN 200710140271 patent/CN101264681B/en not_active Expired - Lifetime
- 2002-06-06 CN CN 200710140272 patent/CN101125472B/en not_active Expired - Lifetime
- 2002-06-06 CN CN2007101402736A patent/CN101125473B/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5019186A (en) * | 1989-06-23 | 1991-05-28 | Kawasaki Steel Corporation | Process for producing chromium-containing steel sheet hot-dip plated with aluminum |
| CN1226288A (en) * | 1996-05-31 | 1999-08-18 | 川崎制铁株式会社 | Plated steel plate |
Non-Patent Citations (3)
| Title |
|---|
| JP昭56-16625A 1981.02.17 |
| JP特开平11-189839A 1999.07.13 |
| JP特开平5-230608A 1993.09.07 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101125472B (en) | 2013-04-17 |
| CN101125473A (en) | 2008-02-20 |
| CN101264681A (en) | 2008-09-17 |
| CN101125472A (en) | 2008-02-20 |
| CN101125473B (en) | 2012-07-18 |
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