CN103290307B - High-strength steel sheet that resistance to impact is superior and manufacture method thereof - Google Patents
High-strength steel sheet that resistance to impact is superior and manufacture method thereof Download PDFInfo
- Publication number
- CN103290307B CN103290307B CN201210044532.6A CN201210044532A CN103290307B CN 103290307 B CN103290307 B CN 103290307B CN 201210044532 A CN201210044532 A CN 201210044532A CN 103290307 B CN103290307 B CN 103290307B
- Authority
- CN
- China
- Prior art keywords
- impact
- steel sheet
- superior
- phase
- resistance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Heat Treatment Of Sheet Steel (AREA)
Abstract
The present invention provides high-strength steel sheet and the manufacture method thereof in the case of not destroying press formability with superior resistance to impact.Described high-strength steel sheet is characterised by, in terms of quality %, containing C:0.05～0.20%, below Si:2.0%, Mn:0.3～3.0%, below P:0.1%, below Al:0.1%, surplus is made up of Fe and inevitable impurity, and there are martensitic phase and 2 phase constitutions of surplus substantially ferritic phase, the volume fraction of martensitic phase is 5～30%, and hardness Hv (M) of martensitic phase is 2.4～4.5 with ratio Hv (the M)/Hv (F) of hardness Hv (F) of ferritic phase.
Description
Technical field
The present invention relates to be suitable to require as such as automotive component steel plate, when punch process superior formability
And the impact with collision as representative during motor-driven vehicle going is required the high-strength of the superior protective action i.e. component of resistance to impact
Degree steel plate and manufacture method thereof.
Background technology
In recent years, the lightweight of car body mainly reduces thickness of slab be achieved by improving armor plate strength.As conventional
The method realizing the high intensity of automobile-use steel plate, such as, exists in Japanese Laid-Open Patent Publication 57-41849 publication disclosed
Method, i.e. the method adding the solution strengthening element such as P, Si under low C to carbide formers such as Nb, Ti.It addition, in day
This JP 60-52528 publication discloses and makes that martensitic phase separates out by high annealing chilling and to obtain ductility excellent
The method of high-strength steel sheet more.
Although these technology already have accounted for press formability, but for the resistance to punching required by parts as all side beam
For hitting characteristic, exist with the problem of Large strain speed deformation when collision, and above-mentioned situation is only based under low strain dynamic speed
Static stretch intensity account for.That is, the intensity of conventional steel plate is to come really according to the static stretch intensity under low strain dynamic speed
Fixed, when being in this impact conditions of collision accident, when namely deforming with Large strain speed, steel plate is passed through
Plastic deformation and absorb absorb can consideration the fewest, it is believed that relative to steel plate during high-speed deformation absorb can static strength
Contribution rate be fixing.
But, according to the research of the present inventor etc., strong relative to the static state absorbing energy of steel plate during high-speed deformation
The contribution rate of degree is not necessarily fixing, the absorption energy of the steel plate when raising of static strength can not directly make high-speed deformation
It is improved.Fig. 1 is (rate of straining=800s-when having arranged dynamic tensile for various steel plates with static strength such as inventor
1) absorption can be with the ratio (quiet dynamic ratio) absorbing energy of (rate of straining=0.01s-1) during static stretch, it is understood that static strength
More increase, then absorb and can more decline by quiet dynamic ratio.As in figure 2 it is shown, according to the load-deformation curve conduct obtained by tension test
Reach the absorption energy of the per unit volume of dependent variable=5% and calculate described absorption energy.
It should be noted that find according to the research of the present inventor etc., when evaluating the resistance to impact of steel plate, by reality
Carry out component impact crushing test obtain crushing absorb can with according to the stress utilizing the high speed tensile test of steel plate to obtain-
Strain curve, Work Hardening Characteristic near yield stress degree of association is the highest, and as representing the value of this characteristic, use is drawn
Dependent variable when stretching reaches the absorption energy of the per unit volume of about 5%.
Therefore, by reduce thickness of slab and realize light-weighted in the case of, when being only evaluated by static strength, for
For the deformation of impact, not obtaining the raising effect of the impact resistance characteristic of expectation degree, impact resistance characteristic is not enough.
Impact resistance characteristic all should be passed through in the case of any one of the deformation of low strain dynamic speed and the deformation of Large strain speed
Absorption during deformation can be evaluated, it is desirable to absorbing can be high.In this case, in order to improve the absorption energy under low strain dynamic speed,
Make steel realize high intensity in terms of static strength, but from the viewpoint of processability, exist in terms of realizing high intensity
Limit.Therefore, in order to realize the raising of punch process and resistance to impact, it is essential, (quiet in equal hot strength
State intensity) under, it is achieved the raising absorbing energy under the deformation of Large strain speed, say, that, it is achieved during the deformation of Large strain speed
The raising of the ratio (quiet dynamic ratio) of the absorption energy (static state absorption energy) when absorption energy (Dynamic Absorption energy) and the deformation of low strain dynamic speed.
Summary of the invention
The present invention completes in view of the above problems, and it provides one to have in the case of not destroying press formability
The high-strength steel sheet of superior resistance to impact and suitable manufacture method thereof.
It should be noted that as the steel plate of excellent impact resistance, such as, at Japanese Laid-Open Patent Publication 52-86919 publication
Disclose adjust in casting process in the implant operation of molten steel and the molten steel in mold add alloying element and have with
Specifically becoming the high-strength steel sheet of the inside and outside two-layer being grouped into, this steel plate is characterised by, by controlling the oxide of weld part
Form and improve the mobility of the motlten metal produced at weld part, thus realize the raising of nugget (nugget) cohesive force, change
Absorption energy during kind impact, but, the impact resistance characteristic of steel plate itself can not be improved, it addition, 2 stratification in casting process are made
Become production efficiency to decline, thus there is unfavorable factor at economic aspect.
The high-strength steel sheet of the present invention has composition of steel described later, and it is martensitic phase and surplus substantially ferritic phase
2 phase constitution steel plates, the volume fraction of martensitic phase is 5～30%, hardness Hv (M) of martensitic phase and hardness Hv of ferritic phase
(F) ratio Hv (M)/Hv (F) is 2.4～4.5.
Here, " substantially ferritic phase " refers to, only containing being added as needed in ferritic phase or ferritic phase
The carbide such as Ti, Nb generate the carbide precipitate of element.
The reason of impact resistance characteristic is improved the most not clearly for 2 phase constitutions according to steel plate of the present invention, hardness ratio, but
It is, it is contemplated that after martensitic volume rate is controlled in suitable scope, by making martensitic phase and ferrite
The hardness ratio of phase becomes big, when static deformation, owing to occupying the movable of most soft ferritic phase and martensite periphery
Indexable is present such that yield stress reduces, and ensures that punch process.On the other hand, when dynamic deformation, ferrum element
The interface of body phase and martensitic phase becomes the obstacle of indexing motion, so that the formation of Nidus Vespae (cell) shape translocation domain is prolonged
Late, therefore, yield stress significantly rises, thus Dynamic Absorption can be expanded relative to the raising effect of static state absorption energy,
Especially, by increasing the hardness ratio of ferritic phase and martensitic phase, the barrier effect of the indexing motion on interface increases, thus
By making Hv (M)/Hv (F) be more than the 2.4 notable risings obtaining yield stress.
Be defined the volume fraction of martensitic phase reason for this is that, if martensite volume is less than 5%, then under Dynamic Absorption energy
Fall, impact resistance characteristic declines.On the other hand, if more than 30%, the most static absorption can uprise, not only impact resistance characteristic decline and
And occur excessive hardening to cause press formability to deteriorate.Therefore, the lower limit of martensite volume is set to 5%, and the upper limit is set to 30%.
It should be noted that the adjustment of martensite volume can start temperature by chilling when adjusting C amount or adjustment hot rolling or annealing
Degree etc. are carried out.
It addition, hardness Hv (M) of martensitic phase is limited with ratio Hv (the M)/Hv (F) of hardness Hv (F) of ferritic phase
Fixed reason for this is that, Hv (M)/Hv (F) is conducive to improving impact resistance characteristic, if less than 2.4, cannot fully improve and absorb energy
Quiet dynamic ratio.It addition, along with the increase of hardness ratio, stretch flanging declines, if more than 4.5, then cannot obtain sufficiently stretching and turn over
Bian Xing, thus press formability deterioration.Therefore, the lower limit of Hv (M)/Hv (F) is set to 2.4, and the upper limit is set to 4.5.It is preferably set to 3.2
～4.0.
It addition, for motor vehicle component, the situation implementing baking vanish after stamping is a lot.Applying this strain
In the case of Ageing Treatment, it is known to following situation, i.e. when remaining solid solution C in ferritic phase, sinter-hardened property (BH
Property) i.e. after Ageing Treatment, yield stress increased.
According to the research of the present inventor etc., for steel plate of the present invention, needed by residual in ferrite
Solid solution C measures, and compared with low speed deformation, the rising of yield stress based on sinter-hardened generation is the most notable under high-speed deformation.
Invention described in technical scheme 4 completes, except specifying the martensite volume in 2 phase constitutions and martensitic phase based on this discovery
With the hardness ratio of ferritic phase, the most further the solid solution C in ferritic phase being measured control is 10～30ppm, from without because of horse
Family name's body mutually near the importing of movable indexing and cause yield point to stretch, by as motor vehicle component stamping laggard
Ageing Treatment during row baking vanish, it is possible to improve further and absorb energy such that it is able to improve impact resistance characteristic.It is less than in solid solution C amount
In the case of 10ppm, the raising effect absorbing energy reduces, if more than 30ppm, then yield point stretching occurs, thus stamping
Property decline.
[invention effect]
According to the high-strength steel sheet of the present invention, by making steel plate tissue become the martensitic phase of specified quantitative and surplus substantially
2 phase constitutions of ferritic phase, and the hardness ratio of 2 phases is defined to setting such that it is able in the feelings not destroying press formability
Superior impact resistance characteristic is obtained under condition.It addition, be 10～30ppm by making the solid solution C amount in ferritic phase, it is possible to substantially
Impact resistance characteristic is made to significantly improve in the case of not producing yield point stretching.It addition, the manufacture method of the present invention is as the present invention
The industrial process of high-strength steel sheet of excellent impact resistance and there is superiority.
Accompanying drawing explanation
Fig. 1 is to represent that dynamic tensile absorbs (under rate of straining 800s-1) to absorb energy (rate of straining with static stretch
Under 0.01s-1) the curve chart of ratio (quiet dynamic than) and the relation of static stretch intensity.
Fig. 2 is the song of the relation absorbing energy of the per unit volume representing load-deformation curve with reaching dependent variable=5%
Line chart.
Detailed description of the invention
2 phase constitutions that steel plate of the present invention is the martensitic phase by ormal weight and surplus substantially ferritic phase is constituted, 2 phases
Solid solution C amount in hardness ratio or furthermore ferrite is adjusted to described setting, by by chemical composition (matter
Amount %) it is defined to following scope, it is possible to it is effectively improved resistance in the case of not causing the various characteristics such as press formability to decline
Impact characteristics.
Comprise C:0.05～0.20%, below Si:2.0%, Mn:0.3～3.0%, below P:0.1%, Al:0.1% with
Under, and surplus is made up of Fe and inevitable impurity.
Or, in addition to described basis, further comprise (below Mo:1.0%, below Cr:2.5%, B:
Less than 0.002%) any more than a kind and/or (Ti, Nb, Zr, V: total amount is less than 0.4%, below Cu:2.5%, Ni:
Less than 1.5%, below Ca:0.02%) any more than a kind.
Hereinafter, the reason of determinant is illustrated.
C:0.05～0.20%
The amount of C processability the most at least more can be improved, but, if less than 0.05%, the volume of martensitic phase
Rate reduces, and is not only difficult to ensure that sufficient intensity, and cannot obtain the effect improving impact absorbing energy significantly.The opposing party
Face, if adding to more than 0.20%, then spot weldability, press formability, especially stretch flanging decline.Therefore, addition
Lower limit is 0.05%, and the upper limit is 0.20%.
Below Si:2.0%
Higher content strengthening and the high intensity for steel plate are effective by Si, and also can improve prolonging of steel plate
Property.Therefore, although as long as the intensity possessed required by steel plate is added, but if add more than 2.0%, then
Easily produce surface blemish, so its upper limit is 2.0%.
Mn:0.3～3.0%
The purpose adding Mn is strengthen steel plate and improve hardenability.But, if less than 0.3%, its effect is too small, but
If adding more than 3.0%, the most not only making press formability deterioration but also spot weldability can be made to decline.Therefore, the lower limit of addition
Being 0.3%, its upper limit is 3.0%.
Below P:0.1%
Owing to P improves the intensity of steel plate by solution strengthening, as long as so the intensity possessed required by steel plate is entered
Row adds.But, if adding more than 0.1%, the most not only make 2 processing embrittlement become notable because of the decline of grain-boundary strength,
But also the decline of impact resistance characteristic can be caused.Therefore, its upper limit is 0.1%.
Below Al:0.1%
Although add Al as deoxidant element, if but add volume, then C system field trash increases and becomes the generation surface flaw
The reason of defect, but also processability can be made to reduce, therefore, its upper limit is 0.1%.
If S, N as inevitable impurity are added by volume, then material behavior can be caused to deteriorate.That is, if S is by volume
Add, then stretch flanging declines, it is therefore preferable that its upper limit is advisable with 0.01%.If it addition, N is added by volume, then often can make
Warm hardening declines and produces yield point stretching, it is therefore preferable that its upper limit is advisable with 0.01%.
In addition to above basis, in order to improve hardenability, can add selected from below Mo:1.0%, Cr:
Less than 2.5%, more than a kind in below B:0.002%.
Below Mo:1.0%
Mo is for improving hardenability and to realize the high intensity of steel plate by precipitation strength and build up be effective.So
And, if adding more than 1.0%, not only causing effect saturated, but also ductility can be caused to decline, therefore, its upper limit is 1.0%.
Preferably, more than 0.05% is added.
Below Cr:2.5%
Cr is for improving hardenability and to realize the high intensity of steel plate by solution strengthening be effective.But, if volume
Adding, the most not only cause effect saturated but also ductility can be made to decline, therefore, its upper limit is 2.5%.Preferably, 0.05% is added
Above.
Below B:0.002%
B is effective to improving hardenability and preventing 2 processing embrittlement by intensity rising and the intercrystalline strengthening of steel plate
, but, if volume is added, then ductility can be caused to decline, therefore its upper limit is 0.002%.Preferably, add 0.0003% with
On.
In addition it is possible to more than a kind added in the case of the effect not hindering the present invention in following element.
Ti, Nb, Zr, V: add up to less than 0.4%
Ti, Nb, Zr, V are effective to being realized the high intensity of steel plate by precipitation strength.But, if too much adding, no
But effect is saturated, but also ductility can be made to decline, so, its upper limit adds up to 0.4%.
Below Cu:2.5%, below Ni:1.5%
Cu, Ni are effective to being realized the high intensity of steel plate by solution strengthening precipitation strength, but also are conducive to
Improve corrosion resistance.But, if volume is added, then ductility can be caused to decline, therefore, the upper limit of Cu addition is 2.5%, Ni's
The upper limit is 1.5%.It should be noted that in the case of individually adding Cu, steel plate may be made to produce surface blemish because of addition,
But can be improved by compound interpolation Ni.
Below Ca:0.02%
Ca has an effect of the inclusion morphology improving steel, and is also effective for improving the processability of steel plate and toughness
's.But, if volume is added, field trash amount increases, and the cold-workability of steel plate and toughness can be caused on the contrary to decline, therefore, on it
It is limited to 0.02%.
It follows that the manufacture method of the explanation present invention.The manufacture method of the present invention is characterised by, to having described one-tenth
After the steel divided carries out hot rolling, carry out cold rolling, then anneal with the soaking temperature of 760～920 DEG C, subsequently, with 15 DEG C/s
Speed below is cooled to 700～540 DEG C from soaking temperature, is then cooled to room temperature with the speed of 100 DEG C/more than s, with laggard
Row reheats and keeps at 150～300 DEG C, then cools down.In reheating the cooling procedure after keeping, pass through
It is cooled to less than 100 DEG C such that it is able to guarantee the solid solution C of ormal weight with the speed of 3 DEG C/more than s.
In the present invention, although carry out hot rolling, cold rolling by usual way, but particularly with hot rolling for,
Suitable reduction ratio (HR leads) between 1150 DEG C～hot Finishing temperatures is more than 85% and hot rolling Finishing temperatures (FT) is 830
More than DEG C, coiling temperature (CT) carries out in the case of being less than 600 DEG C.The reduction ratio between 1150 DEG C～hot Finishing temperatures is made to be
The reason of more than 85% is, it is achieved the granular of hot rolled plate tissue.The reason making hot rolling Finishing temperatures be more than 830 DEG C exists
In, if less than 830 DEG C, then will not become the trickleest hot rolled plate tissue, this also affect cold rolled annealed after tissue and
Become uneven tissue, thus cause processability to deteriorate.It addition, also as rolling load can drastically become big and be difficult to roll
System.The reason making coiling temperature be less than 600 DEG C is to suppress the growth of the tissue of granular because of hot rolling.
In order to carry out recrystallization by the annealing after cold rolling, cold rolling reduction ratio is suitably more than 30%.For this feelings
Annealing under condition is not particularly limited, preferred continuous annealing from the viewpoint of production efficiency and quality stability.
Soaking temperature (ST) during annealing is 760～920 DEG C.If less than 760 DEG C, then the martensite of q.s cannot be obtained
Phase, on the other hand, if more than 920 DEG C, then produces the coarsening of crystal grain, thus causes press formability to deteriorate.
After annealing, with 15 DEG C/s speed below from soaking temperature cooling (slow cooling) to 700～540 DEG C (from the beginning of chilling
Temperature: QT) scope.If higher than 700 DEG C, then becoming insufficient from ferritic phase to the diffusion of the C of austenite phase, it is impossible to obtain
The martensitic phase of hard, the solid solution C in ferrite also can become too much.On the other hand, if less than 540 DEG C, then the analysis of carbide
Going out to be promoted, martensite is met minimizing.If it addition, rate of cooling now is more than 15 DEG C/s, the most as described above, from ferrum element
The diffusion of the C of body austenite phase in opposite directions becomes insufficient, and martensite volume can reduce.
After soaking temperature proceeds by slow cooling, then it is quenched to the purpose of room temperature with the speed of 100 DEG C/more than s and exists
In, prevent because the generation of bainite causes the minimizing of martensite volume.After being once cooled to room temperature, carry out reheating and 150～
The purpose carrying out keeping under 300 DEG C (reheating temperature: QT) is to improve martenaging martempering ductility, if it is low to reheat temperature
In 150 DEG C, then ductility can not get improving, and intensity-ductility balance declines.On the other hand, if higher than 300 DEG C, then martensitic phase
Softening and increase, thus cannot obtain desired hardness, result causes absorption during high-speed deformation to decline.It should be noted that
Although the retention time is not particularly limited, but usual more than 5 seconds, and from the standpoint of production efficiency preferably 180
Below Miao.
For reheating the rate of cooling after keeping (from reheating the rate of cooling that starts of temperature: CR2), by with 3 DEG C/
More than s is cooled to less than 100 DEG C (cooling lower limit temperatures), thereby, it is possible to guarantee suitable solid solution C (10～30ppm).Even if
Rate of cooling be 3 DEG C/more than s but cooling lower limit temperature more than 100 DEG C in the case of, or in the rate of cooling less than 3 DEG C/s
Under, solid solution C reduces, it is impossible to guarantee the solid solution C amount of appropriate amount.
Steel plate of the present invention is not only effective for hot rolled steel plate, and cold-rolled steel sheet also can play its effect, further and
Speech, is also adaptable as the raw sheet of the various plated steel sheets such as molten zinc plating.Although it addition, the manufacture method of the present invention is about cold rolling
The manufacture method of steel plate, but, it will nevertheless be understood that this manufacture method is also used as the various plated steel sheets such as molten zinc plating
The manufacture method of raw sheet uses.
It should be noted that in Japanese Unexamined Patent Publication 7-90482 publication, Japanese Unexamined Patent Publication 7-188833 publication, note
Carry the sheet metal that resistance to impact is superior, on this point of being organized as 2 phase constitutions of martensitic phase and ferritic phase and the present invention
Identical.But, the former is with Nb, Ti as essential component, and by (2Nb+Ti)/C is controlled be 0.1～0.5 realize quiet dynamic
The raising of ratio, it addition, the latter realizes the raising of quiet dynamic ratio by reducing the solid solution C in ferritic phase to measure as far as possible, the two is with logical
The ratio crossing the hardness the making martensitic phase hardness with ferritic phase becomes 2.4～4.5 and realizes absorbing the raising of the quiet dynamic ratio of energy
Steel plate of the present invention entirely different on technological thought.
[embodiment]
(embodiment 1) uses the steel disc of composition shown in table 1 and table 2, carry out according to usual method hot rolling and cold rolling after
Anneal, thus obtain the steel plate of the thickness of slab 1.2mm being made up of 2 phase constitutions of martensitic phase and substantially ferritic phase.Move back
Fire is carried out as follows, i.e. after carrying out soaking at 750～900 DEG C, is cooled to 700～600 with the speed of 10 DEG C/s
DEG C, it is cooled to room temperature with the rate of cooling of 200 DEG C/more than s after further slow cooling, after water-cooled, carries out the tempering of 200～300 DEG C
Process.
[table 1]
[table 2]
For the steel plate obtained, to the volume fraction % of martensitic phase, hardness Hv (M) of martensitic phase and ferritic phase
Hardness Hv (F) is measured and has calculated hardness ratio Hv (M)/Hv (F).About the volume fraction of martensitic phase, according to rolling side
In thickness of slab directional profile at a right angle, from surface to thickness of slab 1/4 the SEM photograph of tissue of position measure.It addition,
Determined the hardness of each phase with load=5gf by Vickers.
It addition, intercept JIS7 test film from these steel plates, with rate of straining=0.01s-1 (static test) and 800s-1
(dynamic test) carries out tension test, and according to static stretch intensity and by the load-deformation curve of each test acquisition, obtaining should
The static state of the per unit volume of variable=5% and Dynamic Absorption energy, and calculate the quiet dynamic ratio absorbing energy, according to this value to resistance to punching
Hit characteristic to be evaluated.
These measure, result of the test illustrates in table 3 and table 4 in the lump.
[table 3]
(note) TS: hot strength, VM: martensitic volume rate, Hv (F): ferrite hardness Hv (M): martensite hardness, Es:
Static stretch absorbs and can absorb energy, the stretching of λ: hole expansibility, YPE1: yield point by Ed: dynamic tensile
[table 4]
(note) TS: hot strength, VM: martensitic volume rate, Hv (M): martensite hardness, Hv (F): ferrite hardness, Es:
Static stretch absorbs energy, Ed: dynamic tensile absorbs energy
Understand as the test portion No.C1 observed in table 3～C5, the C amount as the No.C1 of comparative example low and the present invention's
Outside scope, therefore martensitic volume rate becomes very few, and represent impact resistance characteristic absorbs the quiet dynamic than being conventional level (reference of energy
Fig. 1) degree.On the other hand, in the example of No.C2～C5 in C amount is the scope of the invention, the martensitic phase necessitated
Volume fraction (5～30%), absorb can quiet dynamic ratio be improved, thus obtain superior impact resistance characteristic.
When observing when affecting of Mn addition according to test portion No.D1～D4, owing to the Mn amount of the No.D1 of comparative example is low
And outside the scope of the present invention, so the volume fraction step-down of martensitic phase, thus impact resistance characteristic is the worst.
It addition, when observing when affecting of P addition according to test portion No.E1～E4, as the P of the No.E4 of comparative example
Amount is too much and outside the scope of the present invention, and therefore, Dynamic Absorption can low and impact resistance characteristic deteriorate.
It addition, according to as example, test portion No.H1～H3, I1～I2, J, K1～K2, L1～L2, M1～M2, N1
～knowable to N2, P1～P2, Q1～Q5, add auxiliary element with the scope of technical scheme 2,3 and also will not hinder impact resistance characteristic
Improve.
(embodiment 2), after the steel disc of the composition shown in table 5 is heated to 1200～1250 DEG C, makes the Finishing temperatures be
840～920 DEG C, terminate hot rolling with thickness of slab 4.0mm, after batching at 450～600 DEG C, be cold rolled to thickness of slab 1.2mm, so
After annealed.
[table 5]
Annealing conditions is as shown in table 6 and table 7, after carrying out the soaking of 90 seconds under 740～910 DEG C (soaking temperature: ST), with
40 DEG C/below s (starting the rate of cooling of temperature: CR1 from soaking temperature to chilling) are cooled to 800～545 DEG C, and (chilling starts temperature
Degree: TQ), be then cooled to room temperature, remove a part subsequently, is heated to 70～400 DEG C (reheating temperature: QT), and protects
Hold 300 seconds, then be cooled to 100 with the speed of 1～10 DEG C/s (proceeding by the rate of cooling of cooling: CR2 from reheating temperature)
DEG C (cooling lower limit temperature) below.It addition, the annealed sheet obtained is implemented BH process (after applying 2% prestrain, carry out 170
DEG C × Ageing Treatment of 20 minutes).
For annealing after steel plate, obtain as (embodiment 1) the volume fraction % (VM) of martensitic phase, martensitic phase with
Mechanical property in the hardness ratio (Hv (M)/Hv (F)) of ferritic phase, solid solution C amount, static tensile test, static absorption energy (Es)
And Dynamic Absorption can (Ed) and quiet dynamic ratio thereof, further from BH process after steel plate obtain BH process after Dynamic Absorption energy and
Quiet dynamic ratio.Its result illustrates in table 6, table 7 in the lump.
(note) HR leads: the reduction ratio between 1150 DEG C～hot Finishing temperatures, FT: hot rolling Finishing temperatures, CT: batch temperature
Degree, ST: soaking temperature, QT: chilling starts temperature
CR1: start the rate of cooling of temperature, QT from soaking temperature to chilling: reheat temperature, CR2: from reheating temperature
The rate of cooling of beginning, VM: martensitic volume rate
Hv (M): martensite hardness, Hv (F): ferrite hardness, TS: hot strength, E1: stretching, Es: static absorption energy,
Ed: Dynamic Absorption energy
According to table 6 and table 7, the test portion of example obtains good punch process, impact resistance characteristic.Test portion No.E3,
Z2, AD2 have obtained enough resistances to impact before BH processes, and it is the example of technical scheme 1.But, due to from reheating
The rate of cooling that temperature proceeds by cooling is slow, so solid solution C amount deficiency, thus it is unsatisfactory for the important document of technical scheme 4, because of
This, the raising effect of the resistance to impact after BH process declines slightly.
In contrast, owing to reheating after annealing, cooling as test portion No.A1, A4, C2 and C4 of comparative example
Process, or reheating temperature QT when reheating processes is inappropriate, therefore, under the raising of punch process or absorption energy
Fall.It addition, the chilling of the No.B1 of comparative example starts temperature TQ height, martensitic volume rate increases, and therefore, punch process declines.
Further, since rate of cooling CR1 started from annealing soak temperature as test portion No.G2, G3 of comparative example is fast, institute
Cannot obtain desired martensitic volume rate, thus resistance to impact has declined.
Further, since the composition of steel of test portion No.D, F of comparative example is the most within the scope of the present invention, so martensitic volume rate
Step-down, resistance to impact declines.Furthermore, owing to the P quantitative change of the No.M of comparative example obtains too high, so Dynamic Absorption can become
Low, resistance to impact declines.On the other hand, knowable to as test portion No.N～Y of example, though add the Mo of ormal weight, Cr,
The auxiliary elements such as Ti, Nb, also will not hinder the raising of impact resistance characteristic.
It should be noted that self-evidently, in the manufacture of steel plate of the present invention, not by the above embodiments 1, implement
The manufacturing condition of example 2 limits.It addition, steel plate of the present invention is suitable as the raw steel of automotive component, do not reducing its collision
Being capable of lightweight in the case of safety, but it is clear that is to be not limited to this purposes, and it is applicable to requirement
The various component steel plates of impact resistance characteristic.
Claims (8)
1. the high-strength steel sheet that a resistance to impact is superior, it is characterised in that
In terms of quality %, containing C:0.05～0.20%, below Si:2.0%, Mn:0.3～3.0%, below P:0.1%, Al:
Less than 0.1%, surplus is made up of Fe and inevitable impurity, has volume fraction 5～the martensitic phase of 30% and surplus essence
2 phase constitutions of upper ferritic phase, the hardness of martensitic phase is 2.4～4.5 with the ratio of the hardness of ferritic phase.
The high-strength steel sheet that resistance to impact the most according to claim 1 is superior, it is characterised in that
In addition to the composition described in claim 1, possibly together with below Mo:1.0%, below Cr:2.5%, below B:0.002%
In more than one.
The high-strength steel sheet that resistance to impact the most according to claim 1 and 2 is superior, it is characterised in that
In addition to the composition described in claim 1 or 2, possibly together with Ti, Nb, Zr, V: add up to less than 0.4%, Cu:2.5%
Below, more than one in below Ni:1.5%, below Ca:0.02%.
The high-strength steel sheet that resistance to impact the most according to claim 1 and 2 is superior, it is characterised in that
Solid solution C amount in ferritic phase is 10～30ppm.
The high-strength steel sheet that resistance to impact the most according to claim 3 is superior, it is characterised in that
Solid solution C amount in ferritic phase is 10～30ppm.
6. the manufacture method of the high-strength steel sheet that a resistance to impact is superior, it is characterised in that
After the steel of the composition having in claims 1 to 3 described in any one is carried out hot rolling, carry out cold rolling, then with
The rate of cooling of 15 DEG C/below s is cooled to 700～540 DEG C from annealing soak temperature, then with the cooling speed of 100 DEG C/more than s
Degree is cooled to room temperature, then carries out reheating and keeping at 150～300 DEG C, cools down subsequently.
The manufacture method of the high-strength steel sheet that resistance to impact the most according to claim 6 is superior, it is characterised in that
After keeping at 150～300 DEG C, it is cooled to less than 100 DEG C with the rate of cooling of 3 DEG C/more than s.
8. according to the manufacture method of the superior high-strength steel sheet of the resistance to impact described in claim 6 or 7, it is characterised in that
In hot rolling, to make the reduction ratio between 1150 DEG C～hot Finishing temperatures be more than 85%, hot rolling Finishing temperatures is 830 DEG C
Above, coiling temperature is less than 600 DEG C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210044532.6A CN103290307B (en) | 2012-02-27 | 2012-02-27 | High-strength steel sheet that resistance to impact is superior and manufacture method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210044532.6A CN103290307B (en) | 2012-02-27 | 2012-02-27 | High-strength steel sheet that resistance to impact is superior and manufacture method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103290307A CN103290307A (en) | 2013-09-11 |
| CN103290307B true CN103290307B (en) | 2016-09-21 |
Family
ID=49091825
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210044532.6A Active CN103290307B (en) | 2012-02-27 | 2012-02-27 | High-strength steel sheet that resistance to impact is superior and manufacture method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103290307B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103938097B (en) * | 2014-04-04 | 2016-03-02 | 首钢总公司 | A kind of cold-rolled galvanized duplex steel and preparation method thereof |
| KR101657845B1 (en) * | 2014-12-26 | 2016-09-20 | 주식회사 포스코 | High strength cold rolled steel sheet having excellent surface quality of thin slab and method for manufacturing the same |
| MX2018000328A (en) | 2015-07-13 | 2018-03-14 | Nippon Steel & Sumitomo Metal Corp | Steel sheet, hot-dip galvanized steel sheet, alloyed hot-dip galvanized steel sheet, and production methods therefor. |
| JP6460239B2 (en) | 2015-07-13 | 2019-01-30 | 新日鐵住金株式会社 | Steel sheet, hot-dip galvanized steel sheet, alloyed hot-dip galvanized steel sheet, and methods for producing them |
| CN108277441B (en) * | 2018-04-11 | 2019-12-03 | 东北大学 | A kind of 600MPa grade Ti micro-alloying hot rolling biphase plate and preparation method thereof |
| CN108315663B (en) * | 2018-04-11 | 2019-12-03 | 东北大学 | A kind of 540MPa grade Ti micro-alloying hot rolling biphase plate and preparation method thereof |
| TWI667356B (en) * | 2018-12-11 | 2019-08-01 | 日商新日鐵住金股份有限公司 | High-strength steel sheet excellent in moldability and impact resistance, and method for producing high-strength steel sheet excellent in moldability and impact resistance |
| CN111363978B (en) * | 2018-12-26 | 2021-11-16 | 宝山钢铁股份有限公司 | Welding softening resistant ferrite martensite hot-rolled dual-phase steel and manufacturing method thereof |
| CN110016615B (en) * | 2019-04-26 | 2021-04-20 | 本钢板材股份有限公司 | Cold-rolled dual-phase steel DP780 and flexible production method thereof |
| EP4137602A4 (en) * | 2020-06-30 | 2023-03-29 | JFE Steel Corporation | Galvanized steel sheet, member, and methods for manufacturing same |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3458416B2 (en) * | 1993-09-21 | 2003-10-20 | Ｊｆｅスチール株式会社 | Cold rolled thin steel sheet excellent in impact resistance and method for producing the same |
| JP3887236B2 (en) * | 2002-01-11 | 2007-02-28 | 新日本製鐵株式会社 | High-strength steel sheet, high-strength hot-dip galvanized steel sheet, high-strength alloyed hot-dip galvanized steel sheet excellent in shape freezing property and impact resistance and production method thereof |
| CN101514433A (en) * | 2007-03-16 | 2009-08-26 | 株式会社神户制钢所 | Automobile high-strength electric resistance welded steel pipe with excellent low-temperature impact property and method of manufacturing the same |
| JP5359168B2 (en) * | 2008-10-08 | 2013-12-04 | Ｊｆｅスチール株式会社 | Ultra-high strength cold-rolled steel sheet with excellent ductility and method for producing the same |
-
2012
- 2012-02-27 CN CN201210044532.6A patent/CN103290307B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN103290307A (en) | 2013-09-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103290307B (en) | High-strength steel sheet that resistance to impact is superior and manufacture method thereof | |
| KR101318060B1 (en) | Hot stamping product with advanced toughness and method of manufacturing the same | |
| JP5879364B2 (en) | Steel sheet for molded member having excellent ductility, molded member, and manufacturing method thereof | |
| CN110100032B (en) | Tempered martensitic steel having low yield ratio and excellent uniform elongation and method for producing same | |
| US11377707B2 (en) | Clad steel plate having excellent strength and formability, and production method therefor | |
| US10752968B2 (en) | Ultrahigh-strength high-ductility steel sheet having excellent yield strength, and manufacturing method therefor | |
| JP5598157B2 (en) | Steel sheet for hot press excellent in delayed fracture resistance and collision safety and method for producing the same | |
| US9689050B2 (en) | Rolled steel that hardens by means of precipitation after hot-forming and/or quenching with a tool having very high strength and ductility, and method for manufacturing same | |
| EP2728027B1 (en) | Heat-hardened steel with excellent crashworthiness and method for manufacturing heat-hardenable parts using same | |
| ES2738631T3 (en) | Method for manufacturing a high-strength malleable steel strip annealed continuously | |
| KR20130050138A (en) | Steel sheet for warm press forming, warm press formed parts and method for manufacturing thereof | |
| JP2009545676A (en) | High manganese-type high-strength steel sheet with excellent impact characteristics and manufacturing method thereof | |
| WO2012067474A2 (en) | High-strength steel material having outstanding ultra-low-temperature toughness and a production method therefor | |
| KR20170063613A (en) | High Formability Super Strength Cold-Roll Steel Sheet or Steel Strip, and Manufacturing Method Therefor | |
| KR20150108396A (en) | Ultra-High Strength Cold-Rolled Corten Steel Plate and Method of Fabricating Same | |
| CN101660086A (en) | Light and high-performance twin crystal induced plasticity steel and preparation method thereof | |
| JP2019505668A (en) | High yield ratio type high strength cold-rolled steel sheet and manufacturing method thereof | |
| US11655518B2 (en) | Steel material for taylor welded blank and method for manufacturing hot-stamped part using same steel | |
| CN101353757A (en) | Hot rolling high reaming steel plate having 440MPa grade of tensile strength and manufacturing method thereof | |
| KR101166995B1 (en) | Method for Manufacturing of High Strength and High Formability Galvanized Steel Sheet with Dual Phase | |
| KR102255823B1 (en) | High-strength steel having excellent formability and high yield ratio and method for manufacturing same | |
| KR101988760B1 (en) | Ultra-high strength steel sheet having excellent formability, and method for manufacturing thereof | |
| KR101518588B1 (en) | Precipitation hardening steel sheet having excellent yield strength and yield ratio and method for manufacturing the same | |
| CN111465710B (en) | High yield ratio type high strength steel sheet and method for manufacturing same | |
| US20240141454A1 (en) | Ultra high strength steel sheet having high yield ratio and excellent bendability and method of manufacturing same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |