CN102325916A - High-strength elongation steel sheet, hot-rolled steel sheet, cold-rolled steel sheet, zinc-coated steel sheet, and method for manufacturing alloyed zinc-coated steel sheet - Google Patents
High-strength elongation steel sheet, hot-rolled steel sheet, cold-rolled steel sheet, zinc-coated steel sheet, and method for manufacturing alloyed zinc-coated steel sheet Download PDFInfo
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- CN102325916A CN102325916A CN2009801572626A CN200980157262A CN102325916A CN 102325916 A CN102325916 A CN 102325916A CN 2009801572626 A CN2009801572626 A CN 2009801572626A CN 200980157262 A CN200980157262 A CN 200980157262A CN 102325916 A CN102325916 A CN 102325916A
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/001—Austenite
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/002—Bainite
Abstract
The present invention relates to a steel sheet which is used as structural members of vehicles, and a manufacturing method thereof. The invention provides a method for manufacturing high-strength elongation steel sheets, hot-rolled steel sheets, cold-rolled steel sheets, zinc-coated steel sheets, and alloyed zinc-coated steel sheet. The steel sheet comprises C: 0.5-1.0%, Mn: 0.01-2.0%, Si: 1.0-2.0%, Al: 0.01-2.0%, S: less than 0.012%, Fe: the remaining %, and other inevitable impurities based on weight percent. The inner structure of the steel sheet comprises bainite and remaining austenite. The steel sheet has an average lath width of the bainite: less than 0.3[mu]m, yield strength: more than 700MPa, tensile strength: more than 980MPa, and elongation: more than 20%. The present invention contributes to the weight reduction of the steel sheet for vehicles and crash safety by providing the steel sheet with a yield strength of more than 700MPa, tensile strength of more than 980MPa, elongation of more than 20%, hot-rolled steel sheet, cold-rolled steel sheet, zinc-coated steel sheet, and alloyed zinc-coated steel sheet.
Description
Technical field
The present invention relates to a kind of steel plate that can be used for vehicle structure member and inner panel and preparation method thereof; And more specifically, relate to steel plate and have the method for hot-rolled steel sheet, cold-rolled steel sheet, electrogalvanizing steel plate and the hot-dip galvanizing sheet steel of HS and elongation with preparation with HS and elongation.
Background technology
Recently, limited emission amount of carbon dioxide, and to the requirement that improves the vehicle fuel efficiency uprise gradually in order to protect environment.In addition, in order to ensure passenger's when vehicle collides each other safety, also requiring to improve with the carbody collision characteristic is master's security.Therefore, require to improve the processibility of high tensile steel plate as the scheme of lightweight that realizes carbody and security.
Along with the ys and the tensile strength increase of use steel plate, the lightweight effect of carbody increases, and therefore in automotive industry, the effort of adopting high tensile steel plate is continued carrying out.Recently, developed AHSS (AHSS, Advanced High Strength Steel) with the above tensile strength of 980MPa.Yet when armor plate strength surpassed 980MPa, the shortcoming of existence was that the elongation of steel plate reduces relatively.
Though utilize the exploitation of the TRIP steel of residual austenite to carry out still having the not enough equilibrated shortcoming of intensity and elongation, because tensile strength and elongation product are no more than 25,000MPa% so that overcome this shortcoming.
Based on English Patent 9918240; At USP 6; 884; Described the method that a kind of preparation has high firmness, HS and high ductile steel plate among No. the 3751250th, 306B1, japanese laid-open patent etc., it is through carry out the constant temperature phase transformation to obtain meticulous bainite structure with high-carbon high-alloy steel at low temperatures.
In foregoing invention; Propose a kind of preparation and have at least 50% bainite structure or at least 65% bainite structure and residual austenite method as the steel plate of remaining structure; Said steel plate is to handle laggard line space air cooling but through having the steel that regulation forms through homogenize, then heats again and its constant temperature phase transformation is obtained.Thus, the method that a kind of preparation has the above ultrahigh-strength steel of Hv409 is proposed.Yet, be not useable for hot rolling or annealing process to such an extent as to the shortcoming of existence is the oversize said method of transformation time of said method.
In addition; Carry out the method that the constant temperature phase transformation obtains to have the steel of the elongation more than the tensile strength and 10% more than the 1000MPa though in Korean Patent 2007-0126202, proposed a kind of the processing then under the temperature between Bs temperature and Bs-100 ℃ through austenite phase transformation through steel that regulation is formed; But the shortcoming that exists is; Because need to add expensive alloying element for example Cr, Ni, Mo, so manufacturing cost is higher, and said method is limited to hot-rolled steel sheet.
Though people such as Sandvik are at Metals Technology (p213-220; 1981) propose in through use wherein add 0.65-0.99 weight %C, 2-2.78 weight %Si, 0.5 weight %Mn, 0.02-0.79 weight %Cr and 0-0.03 weight %Ti steel through austenite thermal treatment then in 290 ℃ to 380 ℃ scopes, heat-treat and obtain ultrahigh-strength steel, to such an extent as to but the shortcoming that exists is that the too high levels of Si makes its rolling property cross that difference is very difficult to be applied to hot rolling and cold rolling and said method only limits to hot-rolled steel sheet with said method in the steel.
Summary of the invention
Technical problem
The present invention provides the steel plate with HS and elongation through the components system of control steel and lath (lath) width of bainite and residual austenite on the one hand for addressing the above problem.Another aspect of the present invention provides the method for hot-rolled steel sheet, cold-rolled steel sheet, electrogalvanizing steel plate and hot-dip galvanizing sheet steel that a kind of preparation has HS and elongation.
Technical scheme
According to an instance of the present invention; A kind of steel plate is provided; Comprise Al, the S below the 0.012wt% of Si, the 0.01-2.0wt% of Mn, the 1.0-2.0wt% of C, the 0.01-2.0wt% of 0.5-1.0wt%, Fe and other unavoidable impurities of residue per-cent, the microstructure of its light plate is made up of bainite and residual austenite; The average lath width of bainite is below the 0.3 μ m, and the average lath width of residual austenite is below the 0.3 μ m.The ys that steel plate can have is more than the 700MPa, and tensile strength is more than the 980MPa, and elongation is more than 20%.In addition, steel plate can comprise one or both among the following Cr of Mo and 1.0wt% below the 0.5wt% in addition.In addition, steel plate can comprise B and the following Ti of 0.06wt% below the 0.005wt% in addition.
According to another instance of the present invention; Provide a kind of preparation to have the method for the hot-rolled steel sheet of HS and elongation; Said method comprises: the steel ingot of Fe and other unavoidable impurities of Al, the S below the 0.012wt%, residue per-cent that will comprise Si, the 0.01-2.0wt% of Mn, the 1.0-2.0wt% of C, the 0.01-2.0wt% of 0.5-1.0wt%, and batches at Ms (temperature when martensitic transformation begins) steel ingot under the temperature more than the Ar3 transformation temperature, accomplishing hot rolling through hot rolling to 450 ℃ of scopes.
According to another instance of the present invention; A kind of method for preparing cold-rolled steel sheet is provided; Said method comprises: hot-rolled step will comprise that the C of 0.5-1.0wt%, the Mn of 0.01-2.0wt%, the Si of 1.0-2.0wt%, Al, the S below the 0.012wt%, the Fe of residue per-cent and the steel of other unavoidable impurities of 0.01-1.0wt% pass through hot rolling under the above temperature of Ar3 transformation temperature, to accomplish hot rolling; Batch step, hot-rolled steel sheet is batched under 650 ℃ of following temperature; Annealed under the temperature more than the Ac3 in the cold rolling back of hot-rolled steel sheet, then carry out the refrigerative step; With the ageing treatment step, cold-rolled steel sheet is carried out the overaging processing at Ms (temperature when martensitic transformation begins) to 450 ℃ of scopes.
According to another instance of the present invention; Provide a kind of preparation to have the method for the electrogalvanizing steel plate of HS and elongation; Said method comprises: hot-rolled step will comprise that the C of 0.5-1.0wt%, the Mn of 0.01-2.0wt%, the Si of 1.0-2.0wt%, Al, the S below the 0.012wt%, the Fe of residue per-cent and the steel ingot of other unavoidable impurities of 0.01-1.0wt% pass through hot rolling under the temperature more than the Ar3 transformation temperature, to accomplish hot rolling; Batch step, hot-rolled steel sheet is batched under 650 ℃ of following temperature; Hot-rolled steel sheet is cold rolling, steel plate is annealed under the temperature more than the Ac3, then carry out the refrigerative step; The ageing treatment step is carried out the overaging processing at Ms (temperature when martensitic transformation begins) with cold-rolled steel sheet to 450 ℃ of scopes; With will be through the cold-rolled steel sheet of ageing treatment through zinc-plated bath to form the step of electro-galvanized layer above that.
According to another instance of the present invention; Provide a kind of preparation to have the method for the hot-dip galvanizing sheet steel of HS and elongation; Said method comprises: hot-rolled step will comprise that the C of 0.5-1.0wt%, the Mn of 0.01-2.0wt%, the Si of 1.0-2.0wt%, Al, the S below the 0.012wt%, the Fe of residue per-cent and the steel ingot of other unavoidable impurities of 0.01-1.0wt% pass through hot rolling under the temperature more than the Ar3 transformation temperature, to accomplish hot rolling; Batch step, hot-rolled steel sheet is batched under the temperature below 650 ℃; Hot-rolled steel sheet is cold rolling, steel plate is annealed under the temperature more than the Ac3, then carry out the refrigerative step; The ageing treatment step is carried out the overaging processing at Ms (temperature when martensitic transformation begins) with cold-rolled steel sheet to 450 ℃ of scopes; To pass through zinc-plated bath through the cold-rolled steel sheet of ageing treatment to form the step of electro-galvanized layer above that; Pass through the step of alloying thermal treatment with electrogalvanizing steel plate with the preparation hot-dip galvanizing sheet steel with formation electro-galvanized layer on it.
Beneficial effect
The present invention provides a kind of steel plate, hot-rolled steel sheet, cold-rolled steel sheet, electrogalvanizing steel plate and hot-dip galvanizing sheet steel; Its ys that has is more than the 700MPa; Tensile strength is more than the 980MPa, and elongation is more than 20%, and said steel plate can promote the lightweight of vehicle steel plate and improve collision stability.
Description of drawings
Fig. 1 is one group of microstructure photo of inventive embodiments 13 of the present invention, and Fig. 1 (b) is the enlarged photograph of Fig. 1 (a);
Fig. 2 is one group of microstructure photo of comparative example 18, and Fig. 2 (b) is the enlarged photograph of Fig. 2 (a).
Embodiment
Hereinafter, components system of the present invention will be described.
C：0.5-1.0wt％
When C content is lower than 0.5wt%, can guarantee the intensity of certain level.Yet, be difficult to guarantee the elongation more than 20% to such an extent as to the stability of stable residual austenite is too poor.On the contrary, when C content was higher than 1.0wt%, the phase velocity of bainite sharply reduced and its physical property more is prone to produce deterioration on the contrary with perlite.Therefore, C content can be limited to the scope of 0.5-1.0wt%.
Mn：0.01-2.0wt％
Add Mn and---be equipped with in the process and be included in wherein inevitably---combination to prevent the red brittleness because of the formation generation of FeS, wherein S and Fe at steel.When Mn content was lower than 0.01wt%, content was crossed the low red brittleness that produces.On the contrary, when Mn content surpasses 2.0wt%, the slow turnout that suppresses in the annealing process to such an extent as to the phase velocity of bainite became.Therefore, preferred Mn content is limited to the scope of 0.01-2.0wt%.
Si：1.0-2.0wt％
Because Si promotes ferritic phase transformation and be increased in the carbon content in the austenite of not phase transformation, thereby increase the mark of residual austenite in final product, so it is a kind ofly should actively add the element in the steel.
For the production of the phase transformation steel that contains residual austenite in the present invention, Si must add.When Si content was lower than 1.0wt%, the stabilization of residual austenite maybe be not obvious.On the contrary, when Si content is higher than 2.0wt%, rolling property deterioration, as hot rolling and cold rolling during crack.Therefore, preferred Si content is limited to the scope of 1.0-2.0wt%.
Al：0.01-2.0wt％
Adding Al is for two purposes.The one, the formation of non-metallic inclusion when removing the oxygen that exists in the steel and preventing to solidify, thereby and another purpose be to promote the diffusion of C in austenite stable residual austenite in the present invention.
When Al content is lower than 0.01wt%, can't realize the purpose of its interpolation.When content is higher than 2.0wt%, produce system steel original unit (steel making original unit) rising problem.Therefore, Al content can be limited to the scope of 0.01-2.0wt%.
Yet implement under the situation of annealed cold-rolled steel sheet, electrogalvanizing steel plate and hot-dip galvanizing sheet steel cold rolling in the present invention back, when Al content is too much, along with the Ac3 temperature uprises, under the temperature more than the Ac3, heat-treats the quite difficulty that becomes.Therefore, the upper limit of preferred cold-rolled steel sheet, electrogalvanizing steel plate and hot-dip galvanizing sheet steel is limited to 1.0wt%.
Below the S:0.012wt%
The amount that must keep S is low-level, because formed FeS and caused the red brittleness problem by S, thereby the S level is limited to below the 0.012wt%.Lower limit does not define, because owing to the amount of identical reason S is low more favourable more.
Mo and Cr are optional as required component of adding.
Below the Mo:0.5wt%
Add Mo in order to suppress the generation of perlite phase.When Mo content is higher than 0.5wt%, owing to expensive Mo sharply increases manufacturing cost.Therefore, the content of preferred Mo is limited to the scope below the 0.5wt%.
Below the Cr:1.0wt%
Add Cr in order to suppress the phase transformation of ferritic generation and promotion bainite.When Cr content was higher than 1.0wt%, the amount of solidified C possibly reduce through the formation that promotes the Cr carbide.Therefore, the content of preferred Cr is limited to the scope of 1.0wt%.
B and Ti optionally add as required, can add Ti simultaneously and---exist as impurity---to prevent N and B and combine so that the B effect maximizes.
Below the B:0.005wt%
Add B for suppressing ferritic generation in addition.When B content was higher than 0.005wt%, (C, B) 6 compounds generated and are promoted Fe23, promote ferritic generation on the contrary.Therefore, preferred B content is limited to the scope below the 0.005wt%.
Below the Ti:0.06wt%
When Ti content is higher than 0.06wt%, though exist N (impurity exists with the concentration below the 0.01wt% usually) fully removed also residual extra in a large number Ti and with C bonded problem.Therefore, preferred Ti content is limited to the scope below the 0.06wt%.
Hereinafter, with microstructure, ys, tensile strength and the elongation of describing steel plate of the present invention.
Said microstructure is made up of bainite and residual austenite, and said bainite is preferably the bainite that does not have carbide for the structure of axle polygonal ferrites such as not existing.
Generally speaking, the microstructure of TRIP steel must comprise residual austenite, and the TRIP steel refers to following steel, wherein surpasses 0% fractional residual austenite in theory residual austenite is played an important role in the ductility that strengthens steel through comprising.Therefore, as embodiments of the invention, preferably in the microstructure of TRIP steel the mark of residual austenite can surpass 0% and bainite can form remaining percentage ratio.Yet more preferably the mark of residual austenite can be in the 10-40% scope in microstructure of the present invention, and bainite can be formed remaining percentage ratio.When the mark of residual austenite was lower than 10%, it was in the level of the content that is similar to general known TRIP steel.When mark is higher than 40% when above, the stability degradation of residual austenite.
In addition, the average lath width of bainite and residual austenite is limited to respectively below the 0.3 μ m.When average lath width surpasses 0.3 μ m, can not guarantee intensity to such an extent as to structure is enough meticulous.Therefore, the average lath width of preferred bainite and residual austenite is limited to the scope below the 0.3 μ m.
In addition, the ys of steel plate, tensile strength and elongation are respectively that 700MPa is above, 980MPa above and more than 20%.When ys was lower than 700MPa, steel plate was not suitable for the structural element as vehicle, and when the tensile strength of steel plate be that it is called ultrahigh-strength steel plates to 980MPa when above.In addition, elongation should for more than 20% reaching certain level, thereby the effect that improves processing characteristics can be arranged.
Said steel plate is a kind of in hot-rolled steel sheet, cold-rolled steel sheet, electrogalvanizing steel plate and the hot-dip galvanizing sheet steel.
Hereinafter, with describing a kind of method for preparing hot-rolled steel sheet of the present invention, cold-rolled steel sheet, electrogalvanizing steel plate and hot-dip galvanizing sheet steel.
According to the preparation method of hot-rolled steel sheet according to the invention, steel ingot is passed through the ordinary method reheat to implement hot rolling.
Under the situation of hot-rolled steel sheet, hot rolling is under the temperature more than the Ar3, to accomplish, and to batch be to carry out to 450 ℃ of scopes at Ms (temperature when martensitic transformation begins).
Temperature is accomplished in hot rolling to be limited to more than the Ar3 transformation temperature rolling in two regions to prevent steel plate.When hot rolling is when being lower than the Ar3 transformation temperature and carrying out, steel plate is rolling in two regions, and therefore can cause uneven grain pattern.Therefore, preferred hot rolled completion temperature is limited to more than the Ar3 transformation temperature.
In addition, when coiling temperature is lower than Ms, owing to begin to martensitic transformation, thereby be difficult to obtain the structure of bainite and residual austenite.On the contrary, be to surpass when carrying out under 450 ℃ the temperature when batching, pearlitic transformation can take place.Therefore, preferred coiling temperature is limited to Ms to 450 ℃ scope.
Under the situation of cold-rolled steel sheet; Comprise that the C of 0.5-1.0wt%, the Mn of 0.01-2.0wt%, the Si of 1.0-2.0wt%, Al, the S below the 0.012wt%, the Fe of residue per-cent and the steel of other unavoidable impurities of 0.01-1.0wt% pass through hot rolling under the temperature more than the Ar3 transformation temperature, to accomplish hot rolling; Batch in process below 650 ℃; Cold rolling and annealing cooling then under the above temperature of Ac3, and handle in Ms (temperature when martensitic transformation begins) overaging to 450 ℃ of scopes.
Hot rolled is accomplished temperature and is limited to more than the Ar3 transformation temperature rolling in two regions to prevent steel plate.When hot rolling is to be lower than when carrying out under the temperature of Ar3 transformation temperature, steel plate is rolling in two regions, and therefore can cause uneven grain pattern.Therefore, preferred hot rolled completion temperature is limited to more than the Ar3 transformation temperature.
When coiling temperature is higher than 650 ℃, can seriously cause surface cementation.Yet, do not limit the lower limit of coiling temperature, because also therefore can greatly not influence final structure in cold rolling microstructure before through produce new texture at cold rolling after annealing.
Served as ageing treatment and be when when being lower than Ms, carrying out,, be difficult to obtain the structure of bainite and residual austenite because martensite begins phase transformation.On the contrary, be to surpass when carrying out under 450 ℃ the temperature when batching, pearlitic transformation can take place.Therefore, preferred aging temperature is limited to Ms to 450 ℃ scope.
In addition, cold-rolled steel sheet can pass through zinc-plated bath with the preparation electrogalvanizing steel plate, and the thermal treatment of said electrogalvanizing steel plate process alloying is with the preparation hot-dip galvanizing sheet steel.
Hereinafter, will describe the present invention more in detail through embodiment.
Embodiment
The thickness that preparation has a components system shown in following table 1 is that 90mm and width are the steel billet of 175mm, and 1200 ℃ of reheat 1 hour, and hot rolling subsequently made it have the hot rolling thickness of 3mm with said steel billet.Some steel billets are as the sample of hot-rolled steel sheet, and other steel billets---as sample of cold-rolled steel sheet---pass through the cold rolling annealed thermal treatment of following.
The hot rolling that is used for the sample of hot-rolled steel sheet is accomplished temperature and is set in more than the Ar3 transformation temperature, and said sample is placed in the stove that is preheated to 400 ℃ in cooling, kept 1 hour, and hot rolling reeling is implemented in cooling through stove.
On the contrary; The sample that is used for cold-rolled steel sheet---shown in following table 3---places the stove that is preheated to 600 ℃ to keep 1 hour; And through stove cooling enforcement hot rolling reeling; And hot-rolled sheet is cold rolling to realize the thickness of 1.2mm through 60% once more, 840-900 ℃ of annealing down, then through 400 ℃ of bainitic transformations of implementing down.
Table 1
(wherein, the unit of each component is wt%, and residue percentage ratio is made up of with other unavoidable impurities Fe.)
The steel type that will have the components system shown in table 1 is batched at 400 ℃ and 600 ℃, measures ys, tensile strength and the elongation of hot-rolled steel sheet, and with the result shown in the following table 2.The steel type of components system that will be shown in table 1 is batched at 600 ℃, anneals and ageing treatment.Measure ys, tensile strength and the elongation of cold-rolled steel sheet, and with said result shown in the table 3.
Table 2
In table 2, can find out, confirm that the sample in the inventive embodiments 1 to 8 is to batch at 400 ℃, and the ys of each sample, tensile strength and elongation are respectively, and 700Mpa is above, 980MPa is above and more than 20%.On the contrary, confirm that the sample among the comparative example 1 to 13 is to batch at 600 ℃, and do not satisfy some or all of desired physical propertys, because sample has the ys that is lower than 700Mpa or is lower than the tensile strength of 980MPa or is lower than 20% elongation.
Table 3
In table 3, can find out, confirm that the sample in the inventive embodiments 9 to 17 is through the single region thermal treatment of austenite, and the ys of each sample, tensile strength and elongation are respectively, and 700Mpa is above, 980MPa is above and more than 20%.
On the contrary, the sample among the confirmation comparative example 15 to 20---has aluminium content and the carbon content that is lower than 0.5wt% above 1.0wt%---and has ys that is lower than 700Mpa and the elongation that is lower than 20%.And can not guarantee suitable intensity, because carbon content is low, and its reason is ferritic generation, and is wherein, low and aluminium content high and carry out two region thermal treatments and generate ferritic along with the Ac3 temperature rises owing to carbon content.
Fig. 1 is one group of microstructure photo of inventive embodiments 13 of the present invention, and Fig. 1 (b) is the enlarged photograph of Fig. 1 (a), and wherein dark part is represented bainite and represented austenite than light-colored part.Can find out that separately average lath width is below the 0.3 μ m and it is very fine structure.
On the contrary, Fig. 2 is one group of microstructure photo of comparative example 18, and Fig. 2 (b) is the enlarged photograph of Fig. 2 (a), and dark part is represented bainite and represented austenite than light-colored part.In addition, can find out that to have Polygons perlite and its structure more coarse.
Claims (15)
1. steel plate with HS and elongation comprises Al, the S below the 0.012wt% of Si, the 0.01-2.0wt% of Mn, the 1.0-2.0wt% of C, the 0.01-2.0wt% of 0.5-1.0wt%, Fe and other unavoidable impurities of residue per-cent,
The microstructure of wherein said steel plate is made up of bainite and residual austenite, and the average lath width of bainite is below the 0.3 μ m, and the average lath width of residual austenite is below the 0.3 μ m.
2. the steel plate of claim 1, wherein said steel plate also comprise at least a that A group and B organize;
A group: be selected among the following Cr of Mo and 1.0wt% below the 0.5wt% one or both and
B group: be selected among the following Ti of B and 0.06wt% below the 0.005wt% one or both.
3. claim 1 or 2 steel plate, the ys that wherein said steel plate has is more than the 700MPa, tensile strength is more than the 980MPa, and elongation is more than 20%.
4. claim 1 or 2 steel plate, wherein said steel plate are a kind of in hot-rolled steel sheet, cold-rolled steel sheet, electrogalvanizing steel plate and the hot-dip galvanizing sheet steel.
5. the steel plate of claim 3, wherein said steel plate are a kind of in hot-rolled steel sheet, cold-rolled steel sheet, electrogalvanizing steel plate and the hot-dip galvanizing sheet steel.
6. claim 1 or 2 steel plate, wherein said steel plate are a kind of in cold-rolled steel sheet, electrogalvanizing steel plate and the hot-dip galvanizing sheet steel, and the aluminium content of said steel plate is 0.01-1.0wt%.
7. the steel plate of claim 3, wherein said steel plate are a kind of in cold-rolled steel sheet, electrogalvanizing steel plate and the hot-dip galvanizing sheet steel, and the aluminium content of said steel plate is 0.01-1.0wt%.
8. method for preparing hot-rolled steel sheet with HS and elongation, said method comprises:
To comprise that the C of 0.5-1.0wt%, the Mn of 0.01-2.0wt%, the Si of 1.0-2.0wt%, Al, the S below the 0.012wt%, the Fe of residue per-cent and the steel ingot of other unavoidable impurities of 0.01-2.0wt% pass through hot rolling under the temperature more than the Ar3 transformation temperature, to accomplish hot rolling
And this steel ingot batched to 450 ℃ of scopes at Ms (temperature when martensitic transformation begins).
9. the method for claim 8, wherein said hot-rolled steel sheet also comprise at least a that A group and B organize;
A group: be selected among the following Cr of Mo and 1.0wt% below the 0.5wt% one or both and
B group: be selected among the following Ti of B and 0.06wt% below the 0.005wt% one or both.
10. method for preparing cold-rolled steel sheet with HS and elongation, said method comprises:
Hot-rolled step will comprise that the C of 0.5-1.0wt%, the Mn of 0.01-2.0wt%, the Si of 1.0-2.0wt%, Al, the S below the 0.012wt%, the Fe of residue per-cent and the steel ingot of other unavoidable impurities of 0.01-1.0wt% pass through hot rolling under the temperature more than the Ar3 transformation temperature, to accomplish hot rolling;
Batch step, hot-rolled steel sheet is batched under the temperature below 650 ℃;
Said hot-rolled steel sheet is cold rolling, steel plate is annealed under the temperature more than the Ac3, then carry out the refrigerative step;
The ageing treatment step is carried out the overaging processing at Ms (temperature when martensitic transformation begins) with said cold-rolled steel sheet to 450 ℃ of scopes.
11. the method for claim 10, wherein said cold-rolled steel sheet also comprise at least a of A group and B group;
A group: be selected among the following Cr of Mo and 1.0wt% below the 0.5wt% one or both and
B group: be selected among the following Ti of B and 0.06wt% below the 0.005wt% one or both.
12. a method for preparing the electrogalvanizing steel plate with HS and elongation, said method comprises:
Hot-rolled step will comprise that the C of 0.5-1.0wt%, the Mn of 0.01-2.0wt%, the Si of 1.0-2.0wt%, Al, the S below the 0.012wt%, the Fe of residue per-cent and the steel ingot of other unavoidable impurities of 0.01-1.0wt% pass through hot rolling under the temperature more than the Ar3 transformation temperature, to accomplish hot rolling;
Batch step, hot-rolled steel sheet is batched under the temperature below 650 ℃;
Said hot-rolled steel sheet is cold rolling, steel plate is annealed under the temperature more than the Ac3, then carry out the refrigerative step;
The ageing treatment step is carried out the overaging processing at Ms (temperature when martensitic transformation begins) with said cold-rolled steel sheet to 450 ℃ of scopes; With
To pass through zinc-plated bath through the said cold-rolled steel sheet of ageing treatment to form the step of electro-galvanized layer above that.
13. the method for claim 12, wherein said electrogalvanizing steel plate also comprise at least a of A group and B group;
A group: be selected among the following Cr of Mo and 1.0wt% below the 0.5wt% one or both and
B group: be selected among the following Ti of B and 0.06wt% below the 0.005wt% one or both.
14. a method for preparing the hot-dip galvanizing sheet steel with HS and elongation, said method comprises:
Hot-rolled step will comprise that the C of 0.5-1.0wt%, the Mn of 0.01-2.0wt%, the Si of 1.0-2.0wt%, Al, the S below the 0.012wt%, the Fe of residue per-cent and the steel ingot of other unavoidable impurities of 0.01-1.0wt% pass through hot rolling under the temperature more than the Ar3 transformation temperature, to accomplish hot rolling;
Batch step, hot-rolled steel sheet is batched under the temperature below 650 ℃;
Said hot-rolled steel sheet is cold rolling, steel plate is annealed under the temperature more than the Ac3, then carry out the refrigerative step;
The ageing treatment step is carried out the overaging processing at Ms (temperature when martensitic transformation begins) with said cold-rolled steel sheet to 450 ℃ of scopes;
To pass through zinc-plated bath through the said cold-rolled steel sheet of ageing treatment to form the step of electro-galvanized layer above that; With
With the step of the electrogalvanizing steel plate process alloying thermal treatment that forms electro-galvanized layer on it with the preparation hot-dip galvanizing sheet steel.
15. the method for claim 14, wherein said hot-dip galvanizing sheet steel also comprise at least a of A group and B group;
A group: be selected among the following Cr of Mo and 1.0wt% below the 0.5wt% one or both and
B group: be selected among the following Ti of B and 0.06wt% below the 0.005wt% one or both.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20080133563A KR101091294B1 (en) | 2008-12-24 | 2008-12-24 | Steel Sheet With High Strength And Elongation And Method For Manufacturing Hot-Rolled Steel Sheet, Cold-Rolled Steel Sheet, Galvanized Steel Sheet And Galvannealed Steel Sheet With High Strength And Elongation |
| KR10-2008-0133563 | 2008-12-24 | ||
| PCT/KR2009/002098 WO2010074370A1 (en) | 2008-12-24 | 2009-04-22 | High-strength elongation steel sheet, hot-rolled steel sheet, cold-rolled steel sheet, zinc-coated steel sheet, and method for manufacturing alloyed zinc-coated steel sheet |
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| Publication Number | Publication Date |
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| CN102325916A true CN102325916A (en) | 2012-01-18 |
| CN102325916B CN102325916B (en) | 2013-07-17 |
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| CN200980157262.6A Active CN102325916B (en) | 2008-12-24 | 2009-04-22 | High-strength elongation steel sheet, method for manufacturing hot-rolled steel sheet, cold-rolled steel sheet, zinc-coated steel sheet, and alloyed zinc-coated steel sheet |
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| Country | Link |
|---|---|
| JP (1) | JP5487215B2 (en) |
| KR (1) | KR101091294B1 (en) |
| CN (1) | CN102325916B (en) |
| WO (1) | WO2010074370A1 (en) |
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| CN104160052A (en) * | 2012-03-09 | 2014-11-19 | 株式会社神户制钢所 | Steel sheet for hot pressing use, press-molded article, and method for producing press-molded article |
| CN104160051A (en) * | 2012-03-09 | 2014-11-19 | 株式会社神户制钢所 | Steel sheet for hot pressing use, press-molded article, and method for producing press-molded article |
| CN104204259A (en) * | 2012-03-29 | 2014-12-10 | 株式会社神户制钢所 | High-strength cold-rolled steel sheet, high-strength galvanized steel sheet and high-strength galvannealed steel sheet, having excellent formability and shape fixability, and processes for manufacturing same |
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| CN107109507A (en) * | 2014-12-30 | 2017-08-29 | 韩国机械硏究院 | The outstanding high-strength steel sheet of the combination of intensity and ductility and its manufacture method |
| CN108396237A (en) * | 2017-02-05 | 2018-08-14 | 鞍钢股份有限公司 | A kind of high-ductility cold-reduced sheet and its production method |
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| KR101758003B1 (en) * | 2013-04-15 | 2017-07-13 | 신닛테츠스미킨 카부시키카이샤 | Hot-rolled steel sheet |
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| CN108396237A (en) * | 2017-02-05 | 2018-08-14 | 鞍钢股份有限公司 | A kind of high-ductility cold-reduced sheet and its production method |
| CN108396260A (en) * | 2017-02-05 | 2018-08-14 | 鞍钢股份有限公司 | The high-strength high reaming performance galvanized steel plain sheet of one kind and its manufacturing method |
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Also Published As
| Publication number | Publication date |
|---|---|
| JP5487215B2 (en) | 2014-05-07 |
| CN102325916B (en) | 2013-07-17 |
| KR20100074988A (en) | 2010-07-02 |
| KR101091294B1 (en) | 2011-12-07 |
| WO2010074370A1 (en) | 2010-07-01 |
| JP2012514130A (en) | 2012-06-21 |
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