CN1083902C - Steel sheet with fine square drawing property and making method thereof - Google Patents

Steel sheet with fine square drawing property and making method thereof Download PDF

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CN1083902C
CN1083902C CN97191100A CN97191100A CN1083902C CN 1083902 C CN1083902 C CN 1083902C CN 97191100 A CN97191100 A CN 97191100A CN 97191100 A CN97191100 A CN 97191100A CN 1083902 C CN1083902 C CN 1083902C
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weight
steel
value
steel plate
sheet
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CN1198781A (en
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奥田金晴
河端良和
坂田敬
比良隆明
荻野厚
小原隆史
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JFE Steel Corp
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Kawasaki Steel Corp
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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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0426—Hot rolling
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0447—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment
    • C21D8/0463—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment following hot rolling
    • 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
    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
    • 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
    • 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
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • 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
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0436—Cold rolling

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  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
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  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

A thin steel sheet having excellent rectangular drawability is produced by completing roughing rolling of steel containing C: 0.02 wt % or less, Si: 0.5 wt % or less, Mn: 1.0 wt % or less, P: 0.15 wt % or less, S: 0.02 wt % or less, Al: 0.01 to 0.10 wt %, N: 0.008 wt % or less, at least one of Ti: 0.001 to 0.20 wt % and Nb: 0.001 to 0.15 wt %, the balance comprising Fe, and inevitable impurities, in the temperature region of 950 DEG C. to the Ar3 transformation temperature: performing finish rolling at a reduction of over 70% under lubrication in the temperature region of the Ar3 transformation temperature to 500 DEG C.; pickling the sheet; annealing the resultant hot rolled sheet under conditions which satisfy the equations (1) and (2) below: (T+273) (20+log t)>=2.50x104(1) 745<=T<=920(2) wherein T: hot rolled sheet annealing temperature ( DEG C.) t: hot rolled sheet annealing time (sec); cold rolling at a reduction of 50 to 95%; and then recrystallization annealing; to satisfy the following relations: (rL+rC)/2-rD>=0.67, and (rL+2rD+rC)/4>=2.7, wherein rL: Lankford value in the rolling direction, rD: Lankford value in the direction at 45 DEG with the rolling direction, and rC: Lankford value in the direction perpendicular to the rolling direction.

Description

Steel sheet that rectangular drawing is good and manufacture method thereof
The present invention relates to a kind of steel sheet and manufacture method thereof and using method, this steel sheet is applicable to the shaping of rectangular elements such as automotive oil tank, is the good steel sheet of rectangular drawing shape property.
With member, highly big as automobiles such as fuel tanks for drawing, or complex-shaped shaping, be to adopt the deep-draw steel sheet traditionally.As the necessary material behavior of this deep-draw steel sheet, r value (Lankford value, below brief note is the r value), particularly average r value must high ((r L+ 2r D+ r C)/4, here, r L, r D, r CBe respectively rolling direction, with rolling direction at 45, with the r value of rolling vertical direction).And, all the time, all be to carry out even pull and stretch with all little material of the Two-Dimensional Anisotropic Δ r of r value, to improve qualification rate, wherein, Δ r=(r L+ r C)/2-r DIn addition, this Δ r value is little also helps to improve the r value.
Therefore, traditional developing material all is based on this viewpoint and carries out, and done a lot of effort.For example, developed a kind of cold-rolled steel sheet that carbide constitutes element ti, Nb etc. that in ultra-low carbon steel (C≤0.008% (weight)), adds.And recently, a kind of to this ultra-low carbon steel carry out warm lubrication and rolling, to obtain the technology of average r value up to higher r value more than 2.6, also delivered for example disclosing clear 64-28325 especially and disclose especially on the flat 2-47222 communique.
But, even if the situation of fracture when carrying out rectangular drawing, takes place actual in above-mentioned superelevation r value steel plate when also often having drawing.At this, rectangular drawing is shaped different with axisymmetric cylinder draw forming, is a kind of asymmetric as shown in figure 3 distortion of drawing.All the time, for fear of this fracture, because of thinking that r value deficiency is its reason, thus only note increasing average r value, and reduction Δ r, thereby be devoted to steel plate manufacturing process more and expended great amount of manpower.Even but like this, can not effectively prevent fracture.
And, scrutinize the position of these drawing cracks, not only there is the alpha cleavage of seeing in the common deep-drawing test (deep-draw shaping) (arising from the crackle of punching shoulder), and produces more wall crackle, promptly arise from the wall portion intermediary crackle at angle.These crackles seldom result from the cylinder shaping, but distinctive crackle in the rectangle shaping.
Research to the wall crackle of appearance in this rectangle shaping is less, from the 10th volume of for example " plasticity and processing ", No. 101 (1969-6), only recognize the 425th page: intensity, T value (thickness of slab when crackle produces in the pure bulging is out of shape) are big more, also have the crystallization particle diameter thin more, then the tendency of wall crackle generation is more little.
But the part that forming heights such as fuel tank are big must have high average r value, and there is unapproachable problem on the material in this with this r value main reasons for decrease--high strength, particle diameter refinement contradict as making.And problem is for the T value, does not understand the effective ways that make its raising.
As mentioned above, because less to the research of material behavior in the rectangle shaping, so, the wall crackle that produces when in fact being shaped for rectangle, which aspect factor of steel plate is influential to it, does not also almost completely understand.Under these circumstances, just can not study at present certainly steel plate or its manufacture method with the material behavior that is suitable for the rectangle shaping.
At this, purpose of the present invention just provides a kind of steel sheet and manufacture method thereof, and this steel-sheet rectangular drawing is good, particularly can suppress the generation of rectangular drawing mesospore crackle.
In addition, another purpose of the present invention provides a kind of steel-sheet using method, that is, form when having the rectangle of various planeforms (the plan view shape of drip molding) drawing, and does not crack, and is fit to this shape.
Inventors at first study suppress the necessary material characteristic of wall crackle in rectangular drawing is shaped.And,, recognize in rectangular drawing is shaped that when keeping high average r value, the Two-Dimensional Anisotropic that will contain the r value of Δ r is brought up to certain degree, helps preventing the generation of wall crackle certainly through trial and error method.And, can specifically determine to obtain the good rectangular drawing condition that r value necessary, each in-plane should satisfy that is shaped, even if particularly the relation between rectangular planar shape and the rolling direction changes, also can carry out the condition of good rectangular drawing.
And then, also recognize, in order under the situation that does not reduce average r value, to guarantee the anisotropy of these r values, in creating conditions, the warm lubricated hot rolling in the hot rolling and that this hot-rolled sheet is carried out the condition of annealed mother metal annealing etc. is also very important particularly.
The present invention is based on that these understanding finish, and its main contents are as follows.
(1) steel sheet that has excellent moldability of a kind of rectangular drawing, wherein, the structural constituent of steel plate is:
Below the C:0.02% (weight); Below the Si:0.5% (weight);
Below the Mn:1.0% (weight); Below the P:0.15% (weight);
Below the S:0.02% (weight); Al:0.01～0.10% (weight);
Below the N:0.008% (weight);
And contain a kind or 2 kinds in Ti:0.001～0.20% (weight), Nb:0.001～0.15% (weight); All the other are Fe and inevitable impurity;
Relational expression below the Lankford value of steel plate all directions satisfies:
(r L+r C)/2-r D≥0.67
And (r L+ 2r D+ r C)/4 〉=2.7
Wherein, r L: the Lankford value of rolling direction,
r D: be the Lankford value of 45 ° of directions with rolling direction,
r C: with the vertical Lankford value of rolling direction.
(2) steel sheet that has excellent moldability of a kind of rectangular drawing, wherein, the relational expression below the Lankford value of steel plate all directions also satisfies:
r C-r D〉=0.3 and r L-r DOne of at least relation in 〉=0.3,
Wherein, r L: the Lankford value of rolling direction
r D: with the Lankford value of rolling direction direction at 45
r C: with the vertical Lankford value of rolling direction
(3) as above-mentioned (1) or (2) described steel sheet, wherein, the structural constituent of steel plate also contains B:0.0001～0.01% (weight), and all the other are Fe and inevitable impurity.
(4) as above-mentioned (1) or (2) described steel sheet, wherein, the structural constituent of steel plate also contain in Sb:0.001～0.05% (weight), Bi:0.001～0.05% (weight), Se:0.001～0.05% (weight) more than a kind or 2 kinds, all the other are Fe and inevitable impurity.
(5) as above-mentioned (1) or (2) described steel sheet, wherein, the content of C, N, S, Ti and Nb satisfies relation of plane down in the steel plate:
1.2(C/12+N/14+S/32)＜(Ti/48+Nb/93)
(6) the steel-sheet manufacture method that has excellent moldability of a kind of rectangular drawing, wherein, the steel-sheet structural constituent is
C:0.02% (weight) is following, Si:0.5% (weight) is following,
Mn:1.0% (weight) is following, P:0.15% (weight) is following,
S:0.02% (weight) is following, Al:0.01～0.10% (weight),
Below the N:0.008% (weight),
And contain in Ti:0.001～0.20% (weight), Nb:0.001～0.15% (weight) a kind or 2 kinds, all the other are Fe and inevitable impurity; With these steel at 950 ℃～Ar 3The temperature province of transformation temperature is finished roughing system, then at Ar 3While the temperature province of transformation temperature～500 ℃ is lubricated and is carried out draft and surpass 70% finish rolling system, carry out pickling afterwards, next carrying out mother metal under the condition with resulting slab (1) formula and (2) formula below satisfying anneals, carry out cold rolling with 50%～95% draft then, and carry out recrystallization annealing, (claim scope 9)
(T+273)(20+logt)≥2.50×10 4……(1)
745≤T≤920……(2)
Wherein, T: the mother metal annealing temperature (℃)
T: mother metal annealing time (second)
(7), wherein, also contain B:0.0001～0.01% (weight) in the steel plate composition as above-mentioned (6) described steel-sheet manufacture method.
(8) as above-mentioned (6) or (7) described steel-sheet manufacture method, wherein, also contain in the steel plate composition in Sb:0.001～0.05% (weight), Bi:0.001～0.05% (weight), Se:0.001～0.05% (weight) more than a kind or 2 kinds.
(9) as above-mentioned (6) or (7) described any steel-sheet manufacture method, wherein, the content of C, N, S, Ti and Nb satisfies relation of plane down in the steel plate:
1.2(C/12+N/14+S/32)＜(Ti/48+Nb/93)
The simple declaration of drawing
Fig. 1 is a coordinate diagram, when being illustrated in rectangular drawing, straight portion in the r value of drawing in direction and angle part in the influence of the difference across corner flange of the r value of drawing in direction along the amount of drawing in of wall.
Fig. 2 is a synoptic diagram, is used to illustrate corner flange is influenced by the r value of angle part and straight portion along the amount of drawing in of wall mechanism.
Fig. 3 is for showing that from the steel band the drawing of stamping-out orthogonal is with the synoptic diagram of raw sheet.
Fig. 4 is a coordinate diagram, shows the influence of mother metal annealing temperature to all directions r value.
Fig. 5 is a coordinate diagram, shows the influence of mother metal annealing time to all directions r value.
Fig. 6 is a coordinate diagram, shows r L-r DWith T (unit: K)(20+logt (unit: sec)) between relation.
Fig. 7 is a coordinate diagram, shows (r L+ r C)/2-r DWith T (unit: K)(20+logt (unit: sec)) between relation.
Fig. 8 is a coordinate diagram, shows r L, r D, r CInfluence to rectangular drawing.
Fig. 9 is the figure that shows the definition of straight portion length.Fig. 9 (a) is a diagrammatic sketch of seeing stepped example from the side; Fig. 9 (b) is a diagrammatic sketch of seeing the example of protuberance from the plane.
Below, the present invention will be described in detail.
The wall crackle mechanism of production of inventors during to rectangular drawing studied.Its result has shown following situation:
(1) be easy to generate the steel plate of wall crackle, the flange that demonstrates the bight has and is difficult to the tendency drawn in to wall;
(2) as shown in Figure 1, the bight (is made as r in the r value of drawing in direction T) (be made as r with straight portion in the r value of drawing in direction S) compare more for a short time, corner flange is big more to the amount of drawing in of wall.At this, r SBe the mean value of the straight portion on both sides, angle in the r value of drawing in direction.
At first, the experiment that obtains result shown in Figure 1 is described.
Get the steel plate of the different thick 1.2mm of r value, cut the monolateral rectangle test film of 88mm that is, change the blanking direction of sheet material, make it become 0 °, 45 ° with rolling direction from these steel plates.After these experiment slices are coated slushing oil, make the angle of experiment slice be consistent with the angle of rectangular punch and place, design fold restraint is 4 tons, and forming highly is drawing of 30mm.Drift is a square, and the length of side is 40mm, and the R on limit is 10mm, and drift shoulder R is 5mm.Mensuration is drawn the flange catercorner length before and after the processing, deducts the flange catercorner length that draws after the processing with the flange catercorner length that draws before the processing, with its value 1/2 as the draw in amount of flange to wall.
As described in above-mentioned (2), though the across corner flange is subjected to the influencing mechanism and needn't illustrate that inventors have still done following analysis of r value of bight and straight portion to the amount of drawing in of wall.
In rectangular drawing, because the drawing ratio in bight is very big, so the wall in the bight that only stretches and the flange at angle is drawn in is inconvenient, the flange of straight portion must have the effect of stretching corner flange.Therefore, shown in Fig. 2 signal, like that, can think that the r value that the steel plate straight portion is being drawn in direction (among the figure 2. direction) in the r value of drawing in direction (among the figure 1. direction) than the bight is greatly effective.In this case, the flange of straight portion shrinks greatly during pull and stretch to 3. direction, and the flange that can make the bight stretches to direction 2..
Come what may, recognize that in rectangular drawing, in order to suppress the wall crackle, the r value (r of direction is being drawn in the bight T) drawing in the r value (r of direction than straight portion S) be effective for a short time.And, though in Fig. 1, r SBe the mean value of the straight portion on both sides, angle, but in order to suppress the wall crackle, the r value of the straight portion on both sides, angle much less all must be big in the r value of drawing in direction.
In rectangular drawing, if average r value is low, then also can rupture at aforesaid bight drift shoulder, produce so-called " alpha cleavage ".So its average r value of steel plate that is used for the square tube drawing and forming also must be big.
In general, from steel band, during the raw sheet of stamping-out rectangular shaped article product, consider the utilization rate of raw materials of steel plate, carry out stamping-out as shown in figure 3.In such stamping-out, the rectangle bight to draw in direction roughly consistent with rolling direction direction at 45, straight portion draw in direction and rolling direction or consistent with rolling vertical direction.
Therefore, if according to above-mentioned understanding, the anisotropy Δ r=(r of r value L+ r C)/2-r DGreatly and average r value=(r L+ 2r D+ r CThe steel plate that)/4 are also big has good rectangular drawing.
So inventors are (r in order not reduced average r value L+ r C)/2-r DBig again steel plate is matrix with the steel plate of high r value, and then manufacture method is studied.What obtain the results are shown in Fig. 4～8.
Fig. 4 and Fig. 5 are the synoptic diagram that concerns between the r value of mother metal annealing conditions and steel plate all directions.See that from these figure the mother metal annealing temperature is high more, or the mother metal annealing time is long more, then r DReduce and r LIncrease.And, at this moment, because r CChange not quite, so, r L-r D, r C-r DAnd (r L+ r C)/2-r DIncrease, and (r L+ 2r D+ r C)/4 also increase.
And as Figure 6 and Figure 7, can see r L-r DAnd (r L+ r C)/2-r DAll available mother metal annealing temperature T (℃) (20+logt) adapt with the relational expression (T+273) of mother metal annealing time t (sec).When (T+273) (20+logt) 〉=2.50 * 10 4, r then L-r D〉=0.3 and (r L+ r C)/2-r D〉=0.67.And, at this moment also satisfy r C-r D〉=0.3, reaches (r L+ 2r D+ r C)/4 〉=2.7.
In addition, Fig. 4 is the No.1,4 of table 2 among the described embodiment in back, the result of 7 arrangements; Fig. 5 is the result of No.8,12 in the same table 2,16 arrangements; Fig. 6 and Fig. 7 are the results of the data preparation the No.18,24,25,26,29,30 that creates conditions except that the discontented unabridged version invention of chemical ingredients and hot-rolled condition in the same table 2.At Ar 3Draft is entirely more than 80% in the time of～500 ℃.
About the influence mechanism of mother metal annealing temperature to cold rolled annealed plate r value, though there is no need to verify, the analysis below present inventors have still done:
If mother metal annealing temperature height or mother metal annealing time are long, then the ferro element particle diameter becomes big, the carbonitride balling, and its distribution is also sparse.Owing to these reasons, strain storage capacity and distribution when cold rolling change, and after essence annealing, except that (111) tissue, (211) tissue also has some development, so, can obtain r value as described above.
The mother metal annealing temperature also must satisfy in the condition more than 745 ℃, below 920 ℃ simultaneously except that above-mentioned (T+273) (20+logt) the condition.This is because if the mother metal annealing temperature surpasses 920 ℃, then have the problem that too thick, follow-up surface irregularity when cold rolling of crystallization particle diameter, cold rolling distortion are inhomogeneous, make the decline of r value.On the other hand, if the mother metal annealing temperature less than 745 ℃, then necessary annealing time surpasses 10 hours, and is uneconomical.
Thereby Fig. 8 has concentrated change created conditions and has changed r L, r D, r CThe steel plate result that carries out rectangular drawing test.From seeing,, must satisfy (r here in order to obtain not have the good rectangular drawing of defective L+ r C)/2-r D〉=0.67 and (r L+ 2r D+ r CThe condition of)/4 〉=2.7.Fig. 8 is the result that the data of table 4 and table 5 among the embodiment are put in order.
Inventors further study, if find to satisfy r except that above-mentioned condition again L-r D〉=0.3, r C-r DOne of at least relation in 〉=0.3 then can improve the plasticity of rectangular drawing.These relations obtain from Fig. 8.In addition, when using this class steel plate to carry out rectangular drawing,, then can further improve plasticity certainly if satisfy the back use of following relation with adjusting between orthogonal planeform and the steel-sheet r value.
That is, if establish L LBe length, the L of rectangle straight flange portion in rolling direction CFor the length of rectangle straight flange portion, then according to L in rolling vertical direction LWith L CMagnitude relationship have:
1. work as L L〉=L CThe time,
r C-r D≥0.3
And r L-r D〉=0.4-0.1 (L L/ L C) 2
2. work as L L＜L CThe time,
r L-r D≥0.3
And r C-r D〉=0.4-0.1 (L C/ L L) 2
At this, the length of rectangle straight flange portion is meant the straight flange minister degree of rectangular planar shape.But, the three-dimensional shape of actual rectangle goods seldom has simple solid, see it is stepped shape and see it is the shape that protuberance is arranged from the plane as Fig. 9 (b) as Fig. 9 (a) from the side, the goods of these combinations mostly are the goods with various complicated shapes.Straight portion in this case as shown in Figure 9, is meant minor face and long limit maximum length separately.
As above-mentioned 1., 2. shown in like that, the relational expression of r value since the length of straight portion than and different, its reason can be thought in the rectangular drawing shaping, because the material of long side direction is determining that above-mentioned rectangle is distinctive and is drawing in, so,, also can be shaped fully even drawing in of short leg is few.And recognize that at this moment, the shaping surplus of corresponding straight flange minister degree ratio is subjected to length to compare L L/ L COr L L/ L CSquare influence.
For concerning necessary creating conditions between above-mentioned each r value for satisfying, except that above-mentioned mother metal annealing conditions, other is described as follows.
The slab heating
Being used for the hot rolled Heating temperature should be 900 ℃～1200 ℃ scope.After the heating, carry out hot rolling system, hot rolling system is made up of the finish rolling of roughing and many mill traines.At this moment must make following regulation to roughing and finish rolling.
Roughing system
In order to improve the r value of annealing cold-reduced sheet, must be at the tissue in hot rolling and development (111) orientation, mother metal annealing back.For this reason, importantly utilize roughing to make the preceding tissue of finish rolling thin and even, then, when finish rolling, make evenly to store a large amount of strains on the steel plate, when annealing, preferentially form (111) orientation (crystal orientation).
In order to make tissue before the finish rolling thin and evenly, must make roughing from 950 ℃ to Ar 3Transformation temperature is finished, and produces γ → α phase transformation before finish rolling.Preferably make roughing at Ar 3Finish on the transformation temperature.On the other hand, if the finishing temperature of roughing surpasses 950 ℃, at the Ar that is cooled to produce γ → α phase transformation 3In the process of transformation temperature, take place to reply and grain growth, cause before the smart hot rolling organize thick and inhomogeneous.So the finishing temperature that will make roughing is at Ar below 950 ℃ 3The above scope of transformation temperature is carried out.In addition, for the refinement of organizing, the draft of wishing roughing is more than 50%.
Finish rolling system
Store a large amount of strains when making finish rolling system on steel plate, finish rolling system must be at Ar 3Transformation temperature following with surpass 70%, preferably the draft more than 80% carries out.If surpassing Ar 3Carry out finish rolling system under the temperature of transformation temperature, then produce γ → α phase transformation in the hot rolling, strain relief, it is unordered that rolling structure becomes, and afterwards, preferentially do not form (111) tissue during annealing.On the other hand, if under less than 500 ℃ temperature, carry out finish rolling, then unrealistic because rolling load obviously increases.And, because the total draft of finish rolling is less than 70%, so hot rolling and mother metal annealing back (111) tissue do not develop.
Therefore, the condition of finish rolling system is at Ar 3Between transformation temperature～500 ℃, Ar preferably 3Between transformation temperature～600 ℃ with surpass 70%, preferably the draft more than 80% carries out.
In this finish rolling system,, must be lubricated in order when rolling, evenly to store a large amount of strains.This is because when not being lubricated, the frictional force of roll and surface of steel plate can make steel plate top layer part be subjected to the effect of additional shearing force, does not have tissue growth in (111) orientation (crystal orientation) after hot rolling and the mother metal annealing, the average r value decline of cold rolled annealed plate.
As lubricating method, for example have and graphite, low melting glass are sprayed or spread upon on roll or the steel plate, like this, the frictional coefficient between roll and steel plate can be below 0.15.
Cold rolling draft
In order to make tissue growth, to obtain high average r value and big Δ r, must carry out cold rollingly, its draft must be located at 50～95% scope.If cold rolling draft is less than 50% or all can not get good characteristic greater than 95%.
Smart annealing
Through the cold-rolled steel strip behind the cold rolling process, for recrystallize must carry out essence annealing.The annealed method can be box annealing method or continuous annealing method.The annealed Heating temperature preferably from recrystallization temperature (about 600 ℃) to 950 ℃ scopes.
In addition, on the steel band after the annealing,, also can carry out the skin-pass below 10% in order to proofread and correct shape, adjustment sheet surface roughness.
And the steel plate that is obtained by the present invention also can be used as the raw sheet of processing with surface treated steel plate.At this moment, normally surface of steel plate carry out zinc-plated (alloy system), zinc-plated, enclose surface treatments such as enamel.
Below, the composition tissue that is applicable to suitable steel of the present invention is described.
Below the C:0.02% (weight)
From rectangular drawing, C is few more good more.If its content surpasses 0.02% (weight), then cementite is separated out in hot-rolled sheet in a large number, makes the r value decline after cold rolling, the recrystallization annealing, so, be located at below 0.02% (weight), preferably below 0.008% (weight).
Below the Si:0.5% (weight)
The effect of Si is that steel is strengthened, and corresponding desired intensity is added essential amount.If its addition surpasses 0.5% (weight), can be to rectangular drawing generation detrimentally affect, so, be located at the following scope of 0.5% (weight).
Below the Mn:1.0% (weight)
The effect of Mn is that steel is strengthened, and corresponding desired intensity is added essential amount.If its addition surpasses 1.0% (weight), then the hardness of hot-rolled sheet sharply rises, and unit elongation and r value after cold rolling, the annealing are descended, to rectangular drawing generation detrimentally affect, so, be located at the scope below 1.0% (weight).
Below the P:0.15% (weight)
The effect of P is that steel is strengthened, and corresponding desired intensity is added essential amount.If its addition surpasses 0.15% (weight), owing to be the compound additive with Ti or Nb, thereby phosphide is separated out from hot-rolled sheet in a large number, to the rectangular drawing generation detrimentally affect after cold rolling, the recrystallization annealing, so, be located at below 0.15% (weight).
Below the S:0.02% (weight)
Because MnS and TiS sulfides can make r value and unit elongation descend, so from rectangular drawing, S is few more good more.Its content can allow 0.02% (weight), so, be located at below 0.02% (weight).
Below the Al:0.01% (weight)～0.10% (weight)
But the Al deoxidation is for the utilization ratio that improves carbonitride must corresponding interpolation.Its addition does not reach 0.01% (weight), does not then have the effect of adding; If surpass 0.10% (weight), can not obtain better deoxidation effect even then add again yet, so, be located at the scope of 0.01% (weight)～0.10% (weight).
Below the N:0.008% (weight)
N is solid solution, can reduce ageingly, and that solid solution nitrogen can make is cold rolling, the r value decline after the annealing, so from rectangular drawing, N is few more good more.Its content can allow 0.008% (weight), so, be located at below 0.008% (weight).
Ti:0.001% (weight)～0.20% (weight)
Ti is the carbonitride forming element, its role is to reduce finish rolling before, cold rolling before solid solution C, N in the steel, and finish rolling and cold rolling after annealing operation in (111) tissue is preferentially formed, its interpolation can improve average r value.If its addition does not reach 0.001% (weight), then there is not effect; On the other hand, if surpass 0.20% (weight), can not obtain better effect even add again yet, and can reduce surface quality.So the Ti addition is located at 0.001% (weight)～0.20% (weight), is preferably in the scope of 0.005% (weight)～0.20% (weight), further also can be in the scope of 0.035% (weight)～0.10% (weight).
Nb:0.001% (weight)～0.15% (weight)
Nb is the carbonitride forming element, and is the same with Ti, its role is to reduce finish rolling before, cold rolling before solid solution C, N in the steel, and finish rolling and cold rolling after annealing operation in make the preferential formation of (111) tissue (crystal orientation).And, preferentially form the effect of (111) tissue (crystal orientation) when having the structure refinement that makes before the smart hot rolling, finish rolling and annealing, the effect that also has the average r value of raising.And solid solution Nb also has strain to store effect when smart hot rolling, also has the effect that promotes tissue growth.If the Nb addition does not reach 0.001% (weight), then there is not above-mentioned effect; On the other hand,, can not obtain than above-mentioned better effect yet, moreover, also can cause recrystallization temperature to improve even add again if surpass 0.15% (weight).Therefore, Nb will be at 0.001% (weight)～0.15% (weight), preferably add in the scope of 0.005% (weight)～0.10% (weight).B:0.0001% (weight)～0.01% (weight)
B is the effective element that improves anti-secondary processing brittleness, must corresponding interpolation.If its addition does not reach 0.0001% (weight), then there is not the effect of adding; On the other hand,, can make the rectangular drawing deterioration if surpass 0.01% (weight), so, be in 0.0001% (weight)～0.01% (weight), preferably interpolation in the scope of 0.0001% (weight)～0.005% (weight).
Sb:0.001% (weight)～0.05% (weight), Bi:0.001% (weight)～0.05% (weight), Se:0.001% (weight)～0.05% (weight)
No matter any these elements are, can both play effective function to suppressing the oxidation and the nitrogenize of slab in heat-processed and slab annealing process etc., must corresponding interpolation.If no matter its addition of any element does not reach 0.001% (weight), then there is not the effect of adding; On the other hand,, can make the rectangular drawing deterioration if surpass 0.05% (weight), so, in the scope of 0.001% (weight)～0.05% (weight), add.
1.2(C/12+N/14+S/32)＜(Ti/48+Nb/93)
Be to make N, the C that does not have solid solution condition before the finish rolling system, and the condition of the tissue growth (111) after finish rolling system and slab annealing; And, be cold rolling and smart annealing by carrying out subsequently, further develop the condition of (111) tissue, the average r value of raising.In the present invention, confirmed to make it satisfy 1.2 (C/12+N/14+S/32)＜(Ti/48+Nb/93), then can make finish rolling system not have N, the C of solid solution condition before if the amount of corresponding C, N, S is adjusted the addition of Ti, Nb.
Example
What will have a structural constituent shown in the table 1 thickly is the plate slab of 250mm, after heating, the soaking, under condition shown in table 2 and the table 3, carry out roughing system (adding up to draft 85%) with 3 roughing mills, carry out finish rolling system with 7 smart roller mills again, carry out pickling, mother metal annealing, cold rolling and recrystallization annealing afterwards.Resulting cold rolled annealed plate is carried out r value and rectangular drawing experiment.It the results are shown in table 4 and the table 5.
In addition, the r value is to measure with three point method after 15% the stretching prestrain giving on the JIS5 experiment slice.
In the rectangular drawing experiment, cut the rectangle experiment slice of (a) 88mm * 88mm, (b) 80mm * 96mm, (c) 76mm * 104mm from each steel plate, after these experiment slices are coated slushing oil, making the angle of experiment slice be consistent with the angle of rectangular punch places, design fold restraint is 4 tons, forms highly to be the pull and stretch of 30mm.The shape of drift is respectively (a) 40mm * 40mm (the length ratio is 1: 1), (b) 32mm * 48mm (the length ratio is 1: 1.5), (c) 28mm * 56mm (the length ratio is 1: 2).In this result,, otherwise represent with (*) with shapable usefulness (zero) expression.In addition, the situation for fracture is divided into alpha cleavage (α) and wall crackle (w) with the breaking zone.
Therefrom see, satisfy the steel plate of the present invention of each conditional of r value, all have good rectangular drawing.Correspondence is therewith, and comparative example is when carrying out rectangular drawing, and alpha cleavage, wall crackle all can produce, and plasticity is poor.
And, at Ar 3The draft of the lubrication and rolling of～500 ℃ of temperature provinces is located at more than 80%, can satisfy r C-r D〉=0.3 and r L-r DIn 〉=0.3 any one, no matter how rectangular planar shape can be shaped.
On the other hand, draft more than 70%, r C-r D〉=0.3, and r L-r DCorresponding draft changes.Even in this case, if selected r corresponding L-r DPlaneform, then rectangular drawing does not just become problem.
The invention provides a kind of steel sheet and manufacture method thereof, this steel-sheet rectangular drawing is good, particularly can suppress the generation of rectangular drawing mesospore crackle.And then the present invention also provides a kind of steel-sheet using method, that is, when rectangular drawing is shaped various planeforms (the plan view shape of drip molding), do not crack, and be fit to this shape.
If employing the present invention then can obtain good rectangular drawing.Therefore, to make by welding assembly by several drip moldings traditionally, as the big Rectangular Parts of automotive oil tank class forming height, can easily utilize the drawing manufacturing, can reduce operation, improve productivity, and reduce cost significantly.
Table 1
Grade of steel No. Chemical ingredients % (weight) Formula Ar 3 (℃)
C Si Mn P S Al N Ti Nb B Sb Bi Se
1 0.0020 0.010 0.121 0.010 0.005 0.049 0.0020 0.070 0.015 0.0004 0.0090 trace trace Satisfy 910
2 0.0010 0.010 0.113 0.010 0.005 0.051 0.0021 0.068 0.014 0.0004 0.0090 trace trace Satisfy 910
3 0.0010 0.010 0.125 0.010 0.005 0.020 0.0019 0.068 0.015 0.0004 trace trace trace Satisfy 915
4 0.0010 0.010 0.120 0.010 0.002 0.051 0.0019 0.069 0.014 0.0004 0.0090 trace trace Satisfy 910
5 0.0010 0.011 0.113 0.005 0.005 0.053 0.0020 0.073 0.014 trace 0.0090 trace trace Satisfy 915
6 0.0010 0.011 0.125 0.005 0.002 0.020 0.0019 0.068 0.015 trace trace 0.0010 0.0010 Satisfy 920
7 0.03 0.010 0.124 0.011 0.005 0.051 0.0021 0.014 0.016 0.0004 0.0090 trace trace Do not satisfy 910
8 0.025 0.011 0.119 0.010 0.005 0.048 0.0019 trace 0.250 0.0004 0.0090 trace trace Do not satisfy 910
9 0.0019 0.010 0.116 0.009 0.005 0.048 0.0020 0.015 0.001 0.0004 0.0090 trace trace Do not satisfy 910
10 0.0010 0.010 0.120 0.007 0.005 0.050 0.0022 0.070 trace trace 0.0090 trace trace Satisfy 910
11 0.0009 0.010 0.120 0.007 0.001 0.043 0.0010 trace 0.020 trace trace trace trace Satisfy 910
12 0.0012 0.010 0.121 0.010 0.005 0.049 0.0020 0.070 0.015 0.0004 0.0090 trace trace Satisfy 910
13 0.0010 0.010 0.125 0.010 0.005 0.020 0.0019 0.035 0.016 0.0004 trace trace trace Satisfy 915
14 0.0010 0.011 0.113 0.005 0.005 0.053 0.0020 0.073 0.014 trace 0.0090 trace trace Satisfy 915
15 0.0010 0.011 0.125 0.005 0.002 0.020 0.0019 0.040 0.002 trace trace trace trace Satisfy 920
16 0.0020 0.011 0.119 0.010 0.005 0.048 0.0019 0.001 0.001 0.0004 0.0090 trace trace Do not satisfy 910
17 0.0020 0.400 0.121 0.040 0.005 0.049 0.0020 0.070 0.015 0.0004 0.0090 trace trace Satisfy 910
18 0.0020 0.800 0.8 0.080 0.005 0.049 0.0020 0.070 0.015 0.0004 0.0090 trace trace Do not satisfy 910
19 0.0020 0.010 2.000 0.010 0.005 0.049 0.0020 0.070 0.015 0.0004 0.0090 trace trace Do not satisfy 910
20 0.0020 0.200 0.5 0.080 0.005 0.049 0.0020 0.070 0.015 0.0004 0.0090 trace trace Satisfy 910
21 0.0020 0.010 0.121 0.200 0.005 0.049 0.0020 0.070 0.015 0.0004 0.0090 trace trace Do not satisfy 910
22 0.0020 0.300 0.8 0.040 0.005 0.049 0.0020 0.070 0.015 0.0004 0.0090 trace trace Satisfy 910
Table 2
Experiment No. Grade of steel No. Slab frame temperature (℃) The roughing finishing temperature (℃) Finish rolling Coiling temperature (℃) Motherboard annealing Cold rolling Recrystallization annealing
Ar 3Draft in the time of～500 ℃ (%) The beginning temperature (℃) Finishing temperature (℃) Have unlubricated Temperature (℃) Time (sec) (T+273) (20+logt ) 10 4 Draft (%) Thickness of slab (mm) Temperature (℃) Time
1 1 1000 910 87 770 630 Have 550 750 18000 2.48 76 1.20 910 40s
2 1 1000 910 87 770 630 Have 550 750 18000 2.48 80 1.00 910 40s
3 1 1000 910 87 770 630 Have 550 750 18000 2.48 85 0.85 910 40s
4 1 1000 910 87 770 630 Have 550 800 18000 2.60 76 1.20 910 40s
5 1 1000 910 87 770 630 Have 550 800 18000 2.60 80 1.00 910 40s
6 1 1000 910 87 770 630 Have 560 800 18000 2.60 85 0.85 910 40s
7 1 1000 910 87 770 630 Have 550 850 18000 2.72 76 1.20 910 40s
8 1 1000 910 87 770 630 Have 550 850 18000 2.72 80 1.00 910 40s
9 1 1000 910 87 770 630 Have 650 850 18000 2.72 85 0.85 910 40s
10 1 1000 910 87 770 630 Have 550 750 3600 2.41 80 1.00 910 40s
11 1 1000 910 87 770 630 Have 550 790 3600 2.50 80 1.00 910 40s
12 1 1000 910 87 770 630 Have 550 850 3600 2.65 80 1.00 910 40s
13 1 1000 910 87 770 630 Have 550 900 40 2.53 80 1.00 910 40s
14 1 1000 910 87 770 630 Have 550 800 60 2.34 80 1.00 910 40s
15 1 1000 910 87 770 630 Have 550 830 60 2.40 80 1.00 910 40s
16 1 1000 910 87 770 630 Have 550 850 40 2.43 80 1.00 910 40s
17 1 1000 910 87 770 630 Have 550 890 20 2.48 80 1.00 910 40s
18 1 1000 910 87 770 630 Do not have 550 800 18000 2.60 76 1.20 910 40s
19 2 1020 920 80 880 600 Have 600 800 18000 2.60 80 0.80 880 40s
20 3 1020 930 80 900 600 Have 600 800 18000 2.60 80 0.80 880 40s
21 4 1020 920 84 880 700 Have 600 800 18000 2.60 80 0.80 880 40s
22 5 1050 930 84 900 700 Have 600 800 18000 2.60 80 0.80 880 40s
23 6 1100 950 90 900 700 Have 600 800 18000 2.60 80 0.80 800 5h
24 7 1000 910 87 770 650 Have 580 800 18000 2.60 80 0.80 800 5h
25 8 1000 910 87 770 650 Have 580 800 18000 2.60 80 0.80 800 5h
26 9 1000 820 87 780 650 Have 580 800 18000 2.60 80 0.80 800 5h
27 10 980 915 90 770 630 Have 580 800 18000 2.60 80 0.80 900 40s
28 11 980 915 87 770 630 Have 580 800 18000 2.60 80 0.80 900 40s
29 1 1000 960 87 770 630 Have 580 800 18000 2.60 80 1.00 910 40s
30 1 1000 915 70 820 700 Have 580 800 18000 2.60 80 1.00 910 40s
Table 3
Experiment No. Grade of steel No. Slab heating temperature (℃) The roughing finishing temperature (℃) Finish rolling Coiling temperature (℃) Motherboard annealing Cold rolling Recrystallization annealing
Draft (%) during Ar3～500 ℃ The beginning temperature (℃) Finishing temperature (℃) Have unlubricated Temperature (℃) Time (sec) (T+273) (20+logt) 10 4 Draft (%) Thickness of slab (mm) Temperature (℃) Time
31 12 1000 910 72 770 630 Have 580 800 18000 2.60 80 1.20 910 40s
32 12 1000 910 84 770 630 Have 550 750 360 2.31 85 0.85 910 40s
33 12 1000 910 84 770 630 Have 550 850 18000 2.72 85 0.85 910 40s
34 12 1000 910 84 770 630 Have 550 900 36000 2.88 85 0.85 910 40s
35 12 1000 910 84 770 630 Have 550 850 18000 2.72 80 1.00 910 40s
36 12 1000 910 75 880 775 Have 700 800 36000 2.60 80 1.00 910 40s
37 12 1020 950 84 880 750 Do not have 500 800 18000 2.60 76 1.20 910 40s
38 12 1020 950 84 880 800 Unit 700 850 36000 2.76 76 1.20 850 41s
39 13 1020 920 84 760 600 Have 550 800 18000 2.60 80 0.80 880 40s
40 14 1020 930 84 750 600 Have 550 800 18000 2.60 80 0.80 880 40s
41 15 1020 940 84 760 620 Have 550 800 18000 2.60 80 0.80 880 40s
42 16 1000 910 87 770 650 Have 580 800 18000 2.60 80 0.80 880 5h
43 12 1000 910 72 770 630 Have 550 800 18000 2.60 80 0.80 880 40s
44 12 1000 910 76 770 630 Have 550 800 18000 2.60 80 0.80 880 40s
45 12 1000 910 80 770 630 Have 650 800 18000 2.60 80 0.80 880 40s
46 9 1000 930 85 800 630 Have 650 800 18000 2.60 80 0.80 800 5h
47 17 1000 910 87 770 630 Have 550 800 18000 2.60 85 0.85 910 40s
48 18 1000 910 87 770 630 Have 650 800 18000 2.60 85 0.85 910 40s
49 19 1000 910 87 770 630 Have 550 800 18000 2.60 85 0.85 910 40s
50 20 1000 910 87 770 630 Have 550 800 18000 2.60 85 0.85 910 40s
51 21 1000 910 87 770 630 Have 550 800 18000 2.60 85 0.85 910 40s
52 22 1000 910 87 770 630 Have 550 800 18000 2.60 85 0.85 910 40s
Table 4
Experimental example No. r L r D r C r L-r D r D-r L Δr *1 On average *2The r value According to L L∶L CThe establishment of different formulas and rectangular drawing Remarks
1:2 1:1.5 1:1 1.5:1 2:1
1 2.67 2.72 3.61 -0.05 0.89 0.42 2.93 ×W - ×W - ×W - ×W - ×W Comparative example
2 2 80 2.82 3.71 -0.02 0.89 0.44 3.04 - ×W - ×W - ×W - ×W - ×W Comparative example
3 2.99 2.95 3.78 0.04 0.83 0.44 3.17 - ×W - ×W - ×W - ×W - ×W Comparative example
4 2.83 2.42 3.52 0.41 1.10 0.76 2.80 Y ○ Y ○ Y ○ Y ○ Y ○ Example
5 3.01 2.62 3 64 0.39 1.02 0.71 2.97 Y ○ Y ○ Y ○ Y ○ Y ○ Example
6 3.13 2.72 3.71 0.41 0.99 0.70 3.07 Y ○ Y ○ Y ○ Y ○ Y ○ Example
7 3.00 2.29 3.29 0.71 1.00 0.86 2.72 Y ○ Y ○ Y ○ Y ○ Y ○ Example
8 3.30 2.36 3.44 0 94 1.08 1.01 2.87 Y ○ Y ○ Y ○ Y ○ Y ○ Example
9 3.40 2.79 3.61 0.61 0.82 0.72 3.15 Y ○ Y ○ Y ○ Y ○ Y ○ Example
10 2.75 2.75 3.51 0.00 0.76 0.38 2.94 - ×W - ×W - ×W - ×W - ×W Comparative example
11 2.83 2.52 3.64 0.31 1.12 0.72 2.88 Y ○ Y ○ Y ○ Y ○ Y ○ Example
12 3.21 2.45 3.44 0.76 0.99 0.88 2.89 Y ○ Y ○ Y ○ Y ○ Y ○ Example
13 3.15 2.55 3.51 0.60 0.96 0.78 2.94 Y ○ Y ○ Y ○ Y ○ Y ○ Example
14 2.65 2.70 3.42 -0.05 0.72 0.34 2.87 - ×W - ×W - ×W - ×W - ×W Comparative example
15 2.70 2.66 3.42 0.04 0.76 0.40 2.86 - ×W - ×W - ×W - ×W - ×W Comparative example
16 2.74 2.62 3.43 0.12 0.81 0.47 2.85 - ×W - ×W - ×W - ×W - ×W Comparative example
17 2.78 2.44 3.42 0.34 0.97 0.66 2.77 - ×W - ×W - ×W - ×W - ×W Comparative example
18 2.58 2.38 3.26 0.20 0.88 0.54 2.65 - ×α - ×α - ×α - ×α - ×α Comparative example
19 3.23 2.74 3.81 0.49 1.07 0.78 3.13 Y ○ Y ○ Y ○ Y ○ Y ○ Example
20 3.13 2.64 3.71 0.49 1.07 0.78 3.03 Y ○ Y ○ Y ○ Y ○ Y ○ Example
21 3.21 2.75 3.68 0.46 0.93 0.70 3.10 Y ○ Y ○ Y ○ Y ○ Y ○ Example
22 3.23 2.76 3.72 0.47 0.96 0.72 3.12 Y ○ Y ○ Y ○ Y ○ Y ○ Example
23 3.24 2.81 3.87 0.43 1.06 0.75 3.18 Y ○ Y ○ Y ○ Y ○ Y ○ Example
24 2.42 2.10 3.21 0.32 1.11 0.72 2.46 - ×α - ×α - ×α - ×α - ×α Comparative example
25 2.44 2.15 3.32 0.29 1.17 0.73 2.52 - ×α - ×α - ×α - ×α - ×α Comparative example
26 2.41 2.01 3.25 0.40 1.24 0.82 2.42 - ×α - ×α - ×α - ×α - ×α Comparative example
27 3.24 2.68 3.84 0.56 1.16 0.86 3.11 Y ○ Y ○ Y ○ Y ○ Y ○ Example
28 3.27 2.74 3.72 0.53 0.98 0.76 3.12 Y ○ Y ○ Y ○ Y ○ Y ○ Example
29 2.40 2.30 3.40 0.10 1.10 0.60 2.60 - ×α - ×α - ×α - ×α - ×α Comparative example
30 2.69 2.42 3.09 0.27 0.67 0.40 2.62 - ×α - ×α - ×α - ×α - ×α Comparative example
*1 Δ r=(r L+ r C)/2-r D *2 average r value=(r L+ 2r D+ r C)/4 *The following formula of (y) expression is set up in the 3 left hurdles, and (N) expression is false
Work as L L〉=L CThe time r L-r D〉=0.4-0.1 (L L/ L C) 2
And r C-r D〉=0.3
Work as L in addition L＜L CThe time r C-r D〉=0.4-0.1 (L C/ L L) 2
And r L-r D〉=0.3
Wherein, the situation of average r value＜2.7 and Δ r＜0.67 is not done evaluation, and is simple with "-" expression.
The rectangular drawing performance is represented on right hurdle, symbol " W " expression wall crackle; " α " represents fracture.
Table 5
Experimental example No. r L r D r C r L-r D r D-r L Δr *1 On average *2The r value According to (L L∶L C) establishment and the rectangular drawing of different formula Backup
1∶2 1∶5 1∶1 1. 5∶1 2∶1
31 2.67 2.55 3.82 0.12 1.27 0.70 2.90 N ×W N ×W N ×W N ×W Y ○ Example
32 2.99 2.95 3.71 0.04 0.76 0.40 3.15 - ×W - ×W - ×W - ×W - ×W Comparative example
33 3.14 2.62 3.53 0.52 0 91 0.72 2.98 Y ○ Y ○ Y ○ Y ○ Y ○ Example
34 2.90 2.52 3.40 0.38 0.88 0.63 2.84 - ×W - ×W - ×W - ×W - ×W Comparative example
35 3.32 2.36 3.44 0.96 1.08 1.02 2.87 Y ○ Y ○ Y ○ Y ○ Y ○ Example
36 2.80 2.55 3.70 0.25 1.15 0.70 2.90 Y ○ Y ○ Y ×W N ×W Y ○ Example
37 2.50 2.38 3.26 0.12 0.88 0.50 2.63 - ×α - ×α - ×α - ×α - ×α Comparative example
38 2.80 2.20 2.90 0.60 0.70 0.65 2.53 - ×α - ×α - ×α - ×α - ×α Comparative example
39 3.20 2.70 3.75 0.50 1.05 0.78 3.05 Y ○ Y ○ Y ○ Y ○ Y ○ Example
40 3.13 2.64 3.73 0.49 1.09 0.79 3.04 Y ○ Y ○ Y ○ Y ○ Y ○ Example
41 3.21 2.60 3.80 0.61 1.08 0.85 3.02 Y ○ Y ○ Y ○ Y ○ Y ○ Example
42 2.42 2.10 3.21 0.32 1.11 0.72 2.46 - ×α - ×α - ×α - ×α - ×α Comparative example
43 2.80 2.62 3.90 0.15 1.28 0.73 2.99 N ×W N ×W N ×W N ×W Y ○ Example
44 2.90 2.63 3.85 0.27 1.22 0.75 3.00 N ×W N ×W N ×W Y ○ Y ○ Example
45 3.10 2.65 3.80 0.45 1.15 0.80 3.05 Y ○ Y ○ Y ○ Y ○ Y ○ Example
46 2.89 2.39 3.23 0.50 0.84 0.67 2.73 Y ○ Y ○ Y ○ Y ○ Y ○ Example
47 3.13 2.72 3.71 0.41 -0.41 0.70 3.07 Y ○ Y ○ Y ○ Y ○ Y ○ Example
48 2.40 2.35 3.08 0.05 -0.05 0.39 2.55 - ×α - ×α - ×α - ×α - ×α Comparative example
49 2.21 2.45 2.95 -0.24 0.24 0.13 2.52 - ×α - ×α - ×α - ×α - ×α Comparative example
50 2.95 2.55 3.62 0.40 -0.40 0.74 2.92 Y ○ Y ○ Y ○ Y ○ Y ○ Example
51 2.42 2.10 3.21 0.32 -0.32 0.72 2.46 - ×α - ×α - ×α - ×α - ×α Comparative example
52 3.08 2.65 3.70 0.43 -0.43 0.74 3.02 Y ○ Y ○ Y ○ Y ○ Y ○ Example
*1 Δ r=(r L+ r C)/2-r D *2 average r value=(r L+ 2r D+ r C)/4 *The following formula of (y) expression is set up in the 3 left hurdles, and (N) expression is false
Work as L L〉=L CThe time r L-r D〉=0.4-0.1 (L L/ L C) 2
And r C-r D〉=0.3
Work as L in addition L＜L CThe time r C-r D〉=0.4-0.1 (L C/ L L) 2
And r L-r D〉=0.3
Wherein, the situation of average r value＜2.7 and Δ r＜0.67 is not done evaluation, and is simple with "-" expression.
The rectangular drawing performance is represented on right hurdle, symbol " W " expression wall crackle; " α " represents fracture.

Claims (9)

1. the steel sheet that rectangular drawing is good is characterized in that,
The structural constituent of steel plate is:
Below the C:0.02% (weight); Below the Si:0.5% (weight);
Below the Mn:1.0% (weight); Below the P:0.15% (weight);
Below the S:0.02% (weight); Al:0.01～0.10% (weight);
Below the N:0.008% (weight);
And contain a kind or 2 kinds in Ti:0.001～0.20% (weight), Nb:0.001～0.15% (weight); All the other are Fe and inevitable impurity;
Relational expression below the Lankford value of steel plate all directions satisfies:
(r L+r C)/2-r D≥0.67
And (r L+ 2r D+ r C)/4 〉=2.7
Wherein, r L: the Lankford value of rolling direction,
r D: be the Lankford value of 45 ° of directions with rolling direction,
r C: with the vertical Lankford value of rolling direction.
2. steel sheet as claimed in claim 1 is characterized in that, the relational expression below the Lankford value of steel plate all directions also satisfies:
r C-r D〉=0.3 and r L-r DOne of at least relation in 〉=0.3,
Wherein, r L: the Lankford value of rolling direction,
r D: be the Lankford value of 45 ° of directions with rolling direction,
r C: with the vertical Lankford value of rolling direction.
3. steel sheet as claimed in claim 1 or 2 is characterized in that, the structural constituent of steel plate also contains B:0.0001～0.01% (weight), and all the other are Fe and inevitable impurity.
4. steel sheet as claimed in claim 1 or 2, it is characterized in that, the structural constituent of steel plate also contain in Sb:0.001～0.05% (weight), Bi:0.001～0.05% (weight), Se:0.001～0.05% (weight) more than a kind or 2 kinds, all the other are Fe and inevitable impurity.
5. steel sheet as claimed in claim 1 or 2 is characterized in that, the amount of C, N, S, Ti and Nb satisfies relation of plane down in the steel plate:
1.2(C/12+N/14+S/32)＜(Ti/48+Nb/93)
6. one kind is used to make the good steel-sheet manufacture method of the described rectangular drawing of claim 1, it is characterized in that: with these steel at 950 ℃～Ar 3The temperature province of transformation temperature is finished roughing system, then at Ar 3While the temperature province of transformation temperature～500 ℃ is lubricated and is carried out draft and surpass 70% finish rolling system, carry out pickling afterwards, next carrying out mother metal under the condition with resulting slab (1) formula and (2) formula below satisfying anneals, carry out cold rollingly then with 50～95% draft, and carry out recrystallization annealing.
(T+273)(20+1ogt)≥2.50×10 4……(1)
745≤T≤920……(2)
Wherein, T: the mother metal annealing temperature (℃)
T: mother metal annealing time (second)
7. steel-sheet manufacture method as claimed in claim 6 is characterized in that, also contains B:0.0001～0.01% (weight) in the steel plate composition.
8. as claim 6 or 7 described steel-sheet manufacture method, it is characterized in that, also contain in the steel plate composition in Sb:0.001～0.05% (weight), Bi:0.001～0.05% (weight), Se:0.001～0.05% (weight) more than a kind or 2 kinds.
9. as claim 6 or 7 described steel-sheet manufacture method, it is characterized in that the content of C, N, S, Ti and Nb satisfies relation of plane down in the steel plate:
1.2(C/12+N/14+S/32)＜(Ti/48+Nb/93)
CN97191100A 1996-12-24 1997-11-27 Steel sheet with fine square drawing property and making method thereof Expired - Fee Related CN1083902C (en)

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JPH1150211A (en) * 1997-08-05 1999-02-23 Kawasaki Steel Corp Thick cold rolled steel plate excellent in deep drawing workability and its production
JP4157279B2 (en) † 1998-07-27 2008-10-01 新日本製鐵株式会社 Ferritic steel sheet with excellent shape freezing properties
KR100711356B1 (en) * 2005-08-25 2007-04-27 주식회사 포스코 Steel Sheet for Galvanizing with Superior Formability and Method for Manufacturing the Steel Sheet
CN101514425B (en) * 2008-02-21 2011-05-11 宝山钢铁股份有限公司 Yield strength 160MPa grade building earthquake-resistance low-yield strength steel and method for producing same
CN104789899B (en) * 2015-03-02 2017-09-01 河南工程学院 A kind of counterenamel steel hot-rolled sheet material and its preparation technology
CN111334716B (en) * 2020-03-25 2021-04-13 江西理工大学 Chromium-titanium-boron-containing low-carbon high-strength deep drawing steel and preparation method and application thereof

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JPS6043415B2 (en) * 1980-07-07 1985-09-27 日本鋼管株式会社 Method for producing Al-killed cold-rolled steel sheet for drawing rectangular tubes with excellent wall-plake resistance
JPS6386819A (en) * 1986-09-30 1988-04-18 Kawasaki Steel Corp Production of cold rolled steel sheet for deep drawing
JPH0765118B2 (en) * 1987-05-22 1995-07-12 株式会社神戸製鋼所 Method for producing hot rolled steel sheet with excellent drawability
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