CN1025224C - Cold-rolled high tonsion steel strip having excellent stretching and folding properties, and molten zinc coating steel strip, and process for manufacturing same - Google Patents
Cold-rolled high tonsion steel strip having excellent stretching and folding properties, and molten zinc coating steel strip, and process for manufacturing same Download PDFInfo
- Publication number
- CN1025224C CN1025224C CN 90109291 CN90109291A CN1025224C CN 1025224 C CN1025224 C CN 1025224C CN 90109291 CN90109291 CN 90109291 CN 90109291 A CN90109291 A CN 90109291A CN 1025224 C CN1025224 C CN 1025224C
- Authority
- CN
- China
- Prior art keywords
- weight
- high strength
- annealing
- steel plate
- iron
- 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.)
- Expired - Fee Related
Links
Landscapes
- Heat Treatment Of Sheet Steel (AREA)
- Coating With Molten Metal (AREA)
Abstract
The invention relates to a cold rolled steel plate, a melting galvanized steel plate, and the manufacturing methods thereof with tensile strength over 40 Kgf/mm<+2>, and excellent ductility, more particularly the characteristics of tensile fold. Because the invention appropriately uses tiny and even ferrite phase, therefore, the cold rolled steel plate and the melting galvanized steel plate of the invention are the materials that can maintain the sufficient strength after the molding process and is provided with high yield ratio, which can be used as intensity parts for motor vehicles.
Description
The present invention relates to tensile strength (below use σ
bExpression) be 3.9 * 10
5More than the KPa, and good cold-rolled steel sheet, the hot-dip galvanized steel sheet of ductility, particularly stretch flanging characteristic (stretching び Off ラ Application ジ characteristic), and their manufacture method.
σ surpasses 3.9 * 10
5The high strength cold rolled steel plate of KPa, for example in automotive industry in order to improve security, to reduce fuel cost with lightweight, and strengthen antirust, and higher to the requirement of the hot-dip galvanized steel sheet that uses high strength cold rolled steel plate.In addition, in the building materials purposes, wish that the material of construction thin-walled property to reduce cost, therefore also has very high requirement to high strength cold rolled steel plate.
This high tensile steel plate in above-mentioned all purposes, self-evidently also should satisfy processibilities such as desirable press working.
Attempt to satisfy the technology of these requirements, having the spy to open clear 57-63634 number and 56-13437 communique disclosed is the manufacture method of former material with the Mn-Si steel, but this method mainly is to handle by solution strengthening to make it high strength, want heavy addition to help the Si of high strength, thereby causing surface properties, chemical conversion and immersion plating aspect all have problems.
Other is not as depending on the method for alloying constituent, opens according to as described in the 60-33318 communique as the spy, utilizes the method for recovering annealed structure, but the material instability is arranged, ductility is low, and the problem of aspect such as intra-face anisotropy is big, so that can not low-cost a large amount of the manufacturing.
The present invention relates to a kind of σ
bSurpass 3.9 * 10
5The high strength cold rolled steel plate of KPa and high strength hot dip galvanized steel sheet, its objective is to solving the problem that prior art exists, a kind of high strength cold rolled steel plate that can reach the stretch flanging excellent of following condition, high strength hot dip galvanized steel sheet and their manufacture method are provided.
(1) can avoid adding and surface properties is worsened and, and become low-alloy system the deleterious Si of immersion plating.
(2) improve ductility, particularly the stretch flanging characteristic.
(3) can obtain the few stable material of anisotropy in the plane.
(4) operational condition that needn't the special stipulation strictness.
Present inventors are for addressing the above problem, the steel and various its material and the tissue of creating conditions down of the various composition of comprehensive survey system, investigation result is found, the branch rate of perlite grade in an imperial examination 2 phases is reduced, as the recrystallize ferritic structure, and can obtain extremely excellent stretch flanging characteristic when making its tissue become even subparticle, and then find that the tissue of this hope mainly is to obtain by composition and cold rolling condition annealing conditions best of breed with steel.
The present invention is with the above-mentioned basis that is found to be.
Be that the present invention is a kind of high strength cold rolled steel plate of stretch flanging excellent, its composition is to contain that C:0.03～0.15wt%(is following only to be represented with %), below the Si:0.05%, Mn:0.5～1.2%, Nb: greater than 0.005 less than 0.02% and below the Al:0.10%, surplus is that iron and unavoidable impurities are formed, and has the tissue that the following even fine recrystallize ferrite of average crystal grain particle diameter 20 μ m accounts for 95% above area.
The invention still further relates to the manufacture method of the high strength cold rolled steel plate of stretch flanging excellent.It is characterized in that, to contain C:0.03～0.15%, below the Si:0.05%, Mn:0.5～1.2%, Nb: greater than 0.005 less than 0.02% and below the Al:0.10%, surplus is that the steel that constituted of iron and unavoidable impurities is as former material, after this former material carried out hot rolling, carry out cold rollingly, heating with the rate of heating more than 5 ℃/second on the continuous annealing line subsequently to surpass 50% draft, keep annealing in 20～60 seconds 720 ℃～780 ℃ temperature ranges, cool off then.
The invention still further relates to a kind of high strength hot dip galvanized steel sheet of stretch flanging excellent, its consist of contain C:0.03～0.15%, below the Si:0.05%, Mn:0.5～1.2%, Nb: greater than 0.005 less than 0.02% and below the Al:0.10%, surplus is constituted by iron and unavoidable impurities, and has the tissue that the following even fine recrystallize ferrite of average crystal grain particle diameter 20 μ m accounts for 95% above area.
The invention still further relates to the manufacture method of the high strength fused zinc steel plate of stretch flanging excellent, it is characterized in that, to contain C:0.03～0.15%, below the Si:0.05%, Mn:0.5～1.2%, Nb: greater than 0.005 less than 0.02% and below the Al:0.10%, surplus is that the steel that constituted of iron and inevitable impurity is as former material, after this former material carried out hot rolling, carry out cold rolling with draft above 50%, heat with the rate of heating more than 5 ℃/second on the continuous fusion galvanizing line of annealing way in online subsequently, in 720 ℃～780 ℃ temperature range, keep annealing in 20～60 seconds, in cooling thereafter, then carry out immersion plating and handle.
The invention still further relates to the manufacture method of the high strength hot dip galvanized steel sheet of stretch flanging excellent, it is characterized in that, to contain C:0.03～0.15%, below the Si:0.05%, Mn:0.5～1.2%, Nb: greater than 0.005 less than 0.02% and below the Al:0.10%, surplus is that the steel that constituted of iron and inevitable impurity is as former material, after this former material carried out hot rolling, carry out cold rolling with draft above 50%, heat with the rate of heating more than 5 ℃/second on the continuous fusion galvanizing line of annealing way in online subsequently, in 720 ℃～780 ℃ temperature range, keep annealing in 20～60 seconds, in cooling thereafter, then carry out immersion plating and handle, carry out Alloying Treatment subsequently.
At first illustrate steel plate of the present invention, one-tenth is grouped into the reason that is limited in the above-mentioned scope.
C：0.03～0.15%
C is the most effective as strengthening composition, and price low therefore be the composition of wishing, significantly increase but addition surpasses minute rate of the 2nd phase of 0.15% o'clock perlite etc., ductility particularly stretch flanging significantly worsens, weldability also significantly worsens.On the other hand, during the addition less than 0.03% of C, also can not get enough σ even add other composition
b, therefore, be decided to be 0.03～0.15% scope.
Below the Si:0.05%
Si is effective to the reinforcement of steel, and it is very little to the deleterious effects of ductility, therefore see it is the composition of wishing heavy addition from mechanical properties, but, Scaling significantly worsens owing to making surface properties, and be unfavorable for immersion plating, therefore in order to obtain beautiful surface, its content must be below 0.05%.
Mn：0.5～1.2%
Mn is the efficient hardening composition that its solution strengthening can not can influence C, Si etc.Mn also has the perlite of inhibition and excessively generates and thickization, makes the effect of crystal grain miniaturization.In order to bring into play these effects, the addition of Mn must be more than 0.5%.On the other hand, if Mn amount surpasses 1.2%, then strengthening effect is tending towards saturated, and the 2nd tendency that demonstrates layered distribution mutually, therefore, the stretch flanging deterioration, immersion plating also worsens.Therefore deciding its scope is 0.5～1.2%.
Nb: greater than 0.005 less than 0.02%
The interpolation of Nb and the control of addition are important factors of the present invention.Among the present invention, the additive effect of Nb finally can obtain trickle and uniform recrystallize ferritic structure, consequently improves particularly stretch flanging characteristic of intensity and ductility.Think that Nb may fold as carbonitride, bring above-mentioned desirable effect, but its detailed mechanism is not clear.This ideal effect can only surpass 0.005% and just can obtain at the addition of Nb.Addition because of effect is saturated, is uneconomic therefore during greater than 0.02 weight %.And excessive interpolation can cause being difficult to stably make steel.Therefore, its scope is decided to be greater than 0.005 less than 0.02%.
Below the Al:0.10%
Al: it is integral added ingredients as the deoxidation composition and for the purification of steel.Therefore Al preferably adds 0.005% at least.But, surpassing at 0.10% o'clock, generation aluminum oxide slag etc. causes the dangerous high of surface imperfection, therefore fixes on below 0.10%.
Except that mentioned component, as the unavoidable impurities composition, allow that N, O and S reach 0.0050%, 0.0070% and 0.010% respectively among the present invention.Particularly S makes its reduction can significantly improve the stretch flanging characteristic.So just can reach and make σ
bSurpass 4.4 * 10
5The more high strength of KPa.Therefore, if want to reach high strength, it is favourable reducing S.
The qualification reason of crystal structure below is described.
Purpose of the present invention is to improve ductility as mentioned above, especially the stretch flanging characteristic.
This specific character is that the branch rate with the 2nd phase of perlite etc. reduces, and making recrystallize ferrite branch rate is more than 95%, and can obtain extremely excellent stretch flanging characteristic when making its tissue become the following even particulate of average 20 μ m.
At this moment, the branch rate of perlite (thick especially) that becomes stretch flanging crackle starting point is many more unfavorable more, and if the recrystallize ferritic structure is inhomogeneous and thick unfavorable equally, this is undesirable, therefore, dividing calibration with the recrystallize ferrite is more than 95%, and the ferritic average crystal grain particle diameter of recrystallize is decided to be below the 20 μ m.
Below narrate the qualification reason of creating conditions.
Have no particular limits to the hot rolled operation by the system steel, can make according to normally used method.As representational hot-rolled condition, can exemplify: 1280～1180 ℃ of Heating temperatures, 900～800 ℃ of hot rolling processing temperatures, 650～500 ℃ of coiling temperature.
As for cold rolling, in general its draft is high then helps the granular of organizing after the recrystallization annealing, and in view of this consideration, the following of cold rolling draft is defined as 50%.But, cold rolling draft is brought up to essential value when above, though to the harmless problem that can bring hot rolling motherboard thickness to increase of material face.
About annealing heating rate in the continuous fusion galvanizing line of annealing way in the line of the continuous annealing line of cold-rolled steel sheet and hot-dip galvanized steel sheet, it is fast favourable to recrystallize grain granular, in order to obtain even and trickle recrystallize grain, be necessary it is defined in more than 5 ℃/second, wish more than 10 ℃/second.And the upper limit of rate of heating, in view of the setting of heating installation, the consideration of technology and economic aspects is decided to be 100 ℃/second.
Annealing temperature is decided to be 720～780 ℃.Be lower than 720 ℃ low temperature then recrystallize can not fully carry out, extensibility reduces, stretch flanging also reduces, and therefore can not get satisfied material.If but surpassed 780 ℃ then can produce softening because of crystal grain-growth, this would be undesirable.Among the present invention, owing to add Nb, the carbonitride of Nb suppresses the misgrowth of recrystallize grain, therefore can obtain trickle recrystallize ferrite crystal grain tissue in wide temperature range.
In fact this annealed hold-time does not have good, but considers the stability of material, and the hold-time was favourable more than 20 seconds.Cause the material deterioration if surpass 60 seconds then might grow up, therefore be decided to be 20-60 second because of abnormal grain.
In the purposes of the present invention's steel plate, as the intensity after the forming process of parts, the yielding stress of raw sheet is most important, even therefore often wishing a little sacrifices formability and will guarantee that also yield ratio (Y.R.) is more than 70%, in order to obtain this high strength and suitable yield ratio, in being right after the annealed process of cooling, preferably at least 700～500 ℃ temperature range, carry out speed of cooling and be the chilling more than 20 ℃/second.
During hot-dip galvanized steel sheet is made, the immersion plating after the annealing is handled, there is no particular limitation, handles just with common method immersion plating.And, pay no attention among the present invention and have or not Alloying Treatment.The characteristic variations that this Alloying Treatment causes is very little, becomes identical material in fact.
Embodiment
Embodiment 1
Make the steel billet that the various one-tenth shown in the table 1 are grouped into according to usual way.
These steel billets are carried out hot rolling under condition shown in the table 2, cold rolling, in continuous annealing line, anneal subsequently.
To the steel plate that obtains thus, measure corresponding to the steel plate tensile strength, the lateral bending song of stretch flanging characteristic (サ イ De ベ Application De) tensile properties, evaluation result is shown in table 3, tension test JIS5 test film evaluation.About the bent tensile properties of lateral bending, estimate according to the public clear 50-35438 communique disclosed method of spy, with wide 40mm, the strip test film of long 170mm, consider to have suitable space whenever blocking when particularly making, and process truncation surface for test with sand paper lightly, and make the in-plane bending distortion, estimate the pulled out condition at flange position when crackle takes place.
Table 2
Steel billet adds finish rolling coiling cold rolling Heating temperature annealing annealing time speed of cooling
Rate (%) ℃/second temperature (second) ℃/second under the hot temperature temperature temperature
（℃） （℃） （℃） （℃）
1280 900 600 50 10 740 20 25
1220 780 520
Table 3
Steel σ
sσ
bBent the 2nd phase average ferrite summary of δ Y.R. lateral bending
* 10
5KPa * 10
5The branch rate % size of microcrystal μ m of KPa % % stretching %
B 3.8 4.6 37 83＞60 4 14 embodiment
C 3.9 4.7 35 83＞60 2 12 embodiment
D 3.3 3.5 35 94 58＜1 26 comparative examples
E 3.5 4.8 32 73 45 8 13 comparative examples
F 4.1 4.2 25 98 45 3 25 comparative examples
G 3.7 4.4 33 84 50 2 11 comparative examples
H 3.8 4.2 30 91 48 2 12 comparative examples
I 3.3 3.7 25 89 60 7 25 comparative examples
J 3.8 4.6 37 83＞60 2 13 embodiment
K 3.8 4.8 37 80＞60 4 14 embodiment
L 3.8 4.7 37 81＞60 3 14 embodiment
N 4.0 4.6 37 87＞60 3 14 embodiment
As seen from Table 3, if the present invention's composition compositing range, although be high strength (σ
b〉=3.9 * 10
5KPa), also can obtain good stretching (δ) and lateral bending Qu Lashen, i.e. the stretch flanging characteristic.And can obtain suitable yield ratio.
Embodiment 2
Employing has the steel that table 1 becomes to be grouped into, and is making cold-rolled steel sheet under the various conditions shown in the table 4, and is identical with embodiment 1, and the bent tensile properties of investigation tensile properties and lateral bending the results are shown in table 5.
Table 4
The cold rolling draft rate of heating of steel annealing temperature annealing time speed of cooling summary
(%) (℃/second) (℃) (second) (℃/second)
1 60 12 740 20 25 embodiment
2 70 10 730 40 27 embodiment
3 45 10 740 20 30 comparative examples
4 60 3 740 40 22 comparative examples
5 60 20 760 20 32 embodiment
6 60 12 700 40 28 comparative examples
7 60 12 800 40 30 comparative examples
8 55 15 725 5 25 comparative examples
9 50 15 725 40 30 embodiment
10 60 5 740 30 30 embodiment
11 60 12 780 30 25 embodiment
12 55 10 720 40 25 embodiment
13 60 10 725 60 20 embodiment
Table 5
Steel σ
sσ
bY.R. the average ferrite of bent the 2nd phase of δ lateral bending
* 10
5KPa * 10
5KPa % % stretching % divides rate % size of microcrystal μ m
1 3.8 4.6 83 38 ＞60 1.8 19
2 3.7 4.5 83 39 ＞60 1.7 17
3 6.5 7.0 93 9 20 2.1 24
4 3.7 3.9 95 38 ＞60 3.2 23
5 3.8 4.6 83 36 ＞60 2.1 19
6 5.4 6.4 85 12 28 1.8 a part of non-recrystallizations
7 3.2 3.4 94 35 ＞60 3.1 22
8 4.8 5.5 87 19 30 3 a part of non-recrystallizations
9 3.6 4.5 80 38 ＞60 2.2 17
10 3.9 4.7 83 38 ＞60 1.7 17
11 3.6 4.5 80 38 ＞60 1.5 17
12 3.9 4.8 81 37 ＞60 2.2 17
13 3.8 4.5 85 38 ＞60 1.5 17
Be clear that by table 5,, can obtain one stretching of good intensity and take into account and the stretch flanging characteristic if in the present invention's the scope of creating conditions.
Embodiment 3
For the influence of survey organization to ductility, stretch flanging characteristic, composition shown in the employing table 6 and the steel that are for experiment of creating conditions down and making change and form and treatment condition, investigate their corresponding relation, the results are shown in table 7.
As seen from Table 7, by the branch rate of suitable control the 2nd phase, recrystallize ferrite median size, recrystallize ferrite area occupation ratio then can obtain good material.In the Comparative Examples, 5 σ
b3.9 * 10
5Below the KPa, stretch, the bent tensile properties of lateral bending is good, but the ferrite median size surpasses 20 μ m, the satisfied material of can not saying so.
Table 7
Steel the 2nd phase and ferrite median size recrystallize ferrite δ lateral bending Qu Lashen
Its minute rate (%) (μ m) area occupation ratio (%) % (%)
1 perlite＜2% 14 98 38＞60
2 the same 17～100 38＞60
3 the same 18 90 30 31
4 perlite 7% 14 93 32 36
5 perlite 6% 23 94 33＞60
Embodiment 4
Make the steel billet that various one-tenth are grouped into shown in the table 1 according to usual method.These steel billets are carried out hot rolling, cold rolling under condition shown in the table 8, anneal on the continuous fusion galvanizing line of online subsequently interior annealing way, then carry out immersion plating processing, Alloying Treatment, thereby make alloy galvanized steel plate.
To the steel plate that makes thus, measure the bent tensile properties of its lateral bending corresponding to tensile properties, stretch flanging characteristic, table 9 illustrates its evaluation result.Tension test is with JIS No. 5 test films, also is offside bend tension characteristic, carries out the same evaluation of embodiment 1.
Table 8
Steel billet add finish rolling reel cold rolling rate of heating annealing annealing speed of cooling other
Hot temperature temperature temperature is depressed (℃/second) temperature-time (℃/second)
(℃) (℃) (℃) rate (%) (℃) (second)
1,280 900 600 50 10 740 20 5 alloys
∫ ∫ ∫ ∫
1,220 780 520 20 changes place
Reason
Table 9
Steel σ σ Y.R. δ lateral bending other the 2nd on average the summary
* 10KPa * 10KPa % % song draws the iron element of phase
Stretch % branch rate % body grain
Footpath μ m
B 3.7 4.5 83 37＞60 4 17 embodiment
C 3.9 4.7 83 34＞60 2 15 embodiment
D 3.2 3.4 94 35 57＜1 28 comparative examples
E 3.4 4.7 73 33 44 9 13 comparative examples
F 4.0 4.1 98 25 44 3 26 comparative examples
G 3.7 4.4 84 34 51 2 12 comparative examples
H does not plate 3 12 comparative examples in 3.8 4.2 91 29 49 many places
I 3.3 3.7 89 24 59 7 25 comparative examples
J 3.7 4.4 84 36＞60 5 12 embodiment
K 3.7 4.6 81 37＞60 4 15 embodiment
L 3.7 4.5 83 37＞60 4 15 embodiment
N 3.9 4.5 87 37＞60 2 14 embodiment
Can be clear that by table 9, if the present invention's composition compositing range, although be high strength (σ
b〉=3.9 * 10
5KPa), also can obtain good stretching (δ) and lateral bending Qu Lashen, i.e. the stretch flanging characteristic.
Embodiment 5
Employing has the A steel that table 1 becomes to be grouped into, under each condition shown in the table 10, and the hot-dip galvanized steel sheet of alloying hot-dip galvanized steel sheet and non-alloying, identical with embodiment 1, the bent tensile properties of investigation tensile properties and lateral bending the results are shown in table 11.
Table 10
Cold rolling rate of heating annealing annealing speed of cooling has the alloy-free summary
Following rate (%) (℃/second) temperature-time (℃/second) is changed processing
(℃) (second)
1 60 12 740 20 30 have or not embodiment
2 70 10 730 40 30 have embodiment
3 45 10 740 20 35 have comparative example
4 60 3 740 40 20 have comparative example
5 60 20 760 20 30 have or not embodiment
6 60 12 700 40 29 have comparative example
7 60 12 800 40 30 have comparative example
8 55 15 725 5 27 have comparative example
9 50 15 725 40 30 have embodiment
10 60 5 740 30 30 have embodiment
11 60 12 780 30 25 have embodiment
12 55 10 720 40 20 have embodiment
13 60 10 725 60 25 have embodiment
Table 11
Steel σ
sσ
bY.R. the average ferrite of bent the 2nd phase of δ lateral bending
* 10
5KPa * 10
5KPa % % stretching % divides rate % size of microcrystal μ m
1 3.7 4.5 83 39 ＞60 1.5 18
2 3.7 4.5 83 38 ＞60 1.5 17
3 6.4 6.9 93 8 20 2 25
4 3.7 3.9 95 39 ＞60 3 23
5 3.8 4.6 83 37 ＞60 2 18
6 5.4 6.4 85 12 28 1.5 a part of non-recrystallizations
7 3.2 3.4 94 36 ＞60 3 22
8 4.7 5.4 87 18 30 3 a part of non-recrystallizations
9 3.6 4.5 80 37 ＞60 2.0 18
10 3.7 4.5 83 38 ＞60 1.5 17
11 3.6 4.5 80 39 ＞60 1.5 18
12 3.7 4.6 81 38 ＞60 2.0 17
13 3.8 4.5 85 38 ＞60 1.5 17
Can be clear that by table 11,, then can obtain good intensity-stretching and take into account and the stretch flanging characteristic if in the scope of creating conditions of the present invention.Have or not Alloying Treatment very little, become identical material in fact the influence of material.
Embodiment 6
For survey organization to ductility, the influence of stretch flanging characteristic, composition shown in the employing table 12 and the steel that are for experiment of creating conditions down and making change to be formed and treatment condition, investigate their corresponding relation, the results are shown in table 13.
As seen from Table 13, separation, recrystallize ferrite median size and recrystallize ferrite area occupation ratio by suitable control the 2nd phase then can obtain good material.5 σ in the Comparative Examples
b3.9 * 10
5Below the KPa, stretch, the bent tensile properties of lateral bending is good, but the ferrite grain is through surpassing 20 μ m, the satisfied material of can not saying so.
Table 13
Steel the 2nd phase and ferrite median size recrystallize ferrite δ side rate Qu Lashen
Its minute rate (%) (μ m) area occupation ratio (%) % (%)
1 perlite＜2% 15 98 39＞60
2 the same 18～100 37＞60
3 the same 18 90 31 30
4 perlite 8% 15 92 31 35
5 perlite 7% 25 93 34＞60
Embodiment 7
Adopt the steel of the system of composition shown in the table 14, carry out the hot rolling processing temperature and be 800～850 ℃ hot rolling and cold rolling draft and be 65% cold rolling after, heat and impose 740 ℃ of equal thermal annealings of following 30 seconds with 10 ℃/second, then after carrying out immersion plating processing and further Alloying Treatment, according to embodiment 1 method investigation stretch flanging characteristic.
Table 14
Chemical ingredients (%)
Steel C Si Mn Nb Al N O S
Q 0.07 0.02 0.85 0.010 0.025 0.020 0.010 0.010
R 0.08 0.02 0.80 0.012 0.035 0.025 0.015 0.007
S 0.07 0.01 0.75 0.010 0.020 0.025 0.010 0.005
T 0.07 0.02 0.75 0.012 0.025 0.025 0.010 0.003
U 0.08 0.01 0.85 0.012 0.025 0.025 0.010 0.001
In this test, its condition should be stricter than embodiment 1, and the gap when blocking is bigger than common, and do not carry out end face fully and handle for test, and it the results are shown in table 15.
Table 15
Steel lateral bending Qu Lashen
Q 55%
R 57%
S ＞60%
T ＞60%
U ＞60%
In the table 15, the lateral bending song of steel Q is stretched as 55%, and this value is more much better than former steel, then can further improve this characteristic but further reduce S.In the table 15,＞60% expression test film pushes through the crackle state does not take place between anchor clamps, and expression has the bent tensile properties (stretch flanging characteristic) of extremely excellent lateral bending.
The present invention relates to the high strength cold rolled steel plate of a kind of with in the past different high strength and ductility, stretch flanging excellence, and dissolve steel plate galvanized.In the past, as σ
bBe 3.9 * 10
5The high tensile steel plate that KPa is above, majority cracks because of shortcoming stretch flanging, and be difficult to obtain as parts such as automobile, to require the material that can keep enough intensity and have high yield ratio after the forming process, and when hot-dip galvanized steel sheet carries out surface treatment, become the obstacle of high strength and immersion plating etc.And the present invention has been owing to used trickle and uniform ferritic phase suitably, thereby solved this problem.Mainly can be used as the Rustproof Steel Plate of automobile with strength member.
Claims (5)
1, a kind of high strength cold rolled steel plate of stretch flanging excellent is characterized in that, it contains:
C:0.03～0.15 weight %,
Below the Si:0.05 weight %,
Mn:0.5～1.2 weight %,
Nb: greater than 0.005 less than 0.02 weight %,
Below the Al:0.10 weight %,
And surplus is made of iron and unavoidable impurities, and to have the average crystal grain particle diameter be that the area occupation ratio of the following even trickle recrystallize ferritic structure of 20 μ m is the tissue more than 95%.
2, a kind of manufacture method of high strength cold rolled steel plate of stretch flanging excellent is characterized in that, will contain
C:0.03～0.15 weight %,
Si:0.05 weight %,
Mn:0.5～1.2 weight %,
Nb: greater than 0.005 less than 0.02 weight %,
Below the Al:0.10 weight %,
And the steel that surplus is made of iron and inevitable impurity is as former material,
After this former material carried out hot rolling,
Carry out draft and be cold rolling more than 50%,
Then heating with the rate of heating more than 5 ℃/second on the continuous annealing line and in 720 ℃～780 ℃ temperature range, keeping annealing in 20～60 seconds, cool off then.
3, a kind of high strength hot dip galvanized steel sheet of stretch flanging excellent, it is characterized in that: it contains:
C:0.03～0.15 weight %,
Below the Si:0.05 weight %,
Mn:0.5 weight %,
Nb: greater than 0.005 less than 0.02 weight %,
Below the Al:0.10 weight %,
And surplus is made of iron and unavoidable impurities,
And having the average crystal grain particle diameter is that the plain area occupation ratio of organizing of the following even trickle recrystallize iron of 20 μ m is the tissue more than 95%.
4, a kind of high strength hot dip galvanized steel sheet manufacture method of stretch flanging excellent is characterized in that, will contain
C:0.03～0.15 weight %,
Si:0.05 weight %,
Mn:0.5～1.2 weight %,
Nb: greater than 0.005 less than 0.02 weight %,
Below the Al:0.10 weight %,
And the steel that surplus is made of iron and inevitable impurity is as former material,
After this former material carried out hot rolling,
Carry out draft and be cold rolling more than 50%,
Then in online on the continuous fusion galvanizing line of annealing way with the heating of the rate of heating more than 5 ℃/second and in 720 ℃～780 ℃ temperature range, keep annealing in 20～60 seconds, in cooling thereafter, proceed immersion plating and handle.
5, a kind of manufacture method of high strength galvanized steel plate of stretch flanging excellent is characterized in that, it contains
C:0.03～0.15 weight %,
Below the Si:0.05 weight %,
Mn:0.5～1.2 weight %,
Nb: greater than 0.005 less than 0.02 weight %,
Below the Al:0.10 weight %,
And the steel that surplus is made of iron and inevitable impurity is as former material,
After this former material carried out hot rolling,
Carry out draft and be cold rolling more than 50%,
Then heat with the rate of heating more than 5 ℃/second on the continuous fusion galvanizing line of annealing way in online, and in 720 ℃～780 ℃ temperature range, keep 20-60 to anneal second, in cooling thereafter, proceed immersion plating and handle and later alloy treatment.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP296158/89 | 1989-11-16 | ||
| JP29615889 | 1989-11-16 | ||
| JP88122/90 | 1990-04-04 | ||
| JP276471/90 | 1990-10-17 | ||
| JP2276471A JP2688384B2 (en) | 1989-11-16 | 1990-10-17 | High-strength cold-rolled steel sheet and hot-dip galvanized steel sheet having excellent stretch flange characteristics, and methods for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1051764A CN1051764A (en) | 1991-05-29 |
| CN1025224C true CN1025224C (en) | 1994-06-29 |
Family
ID=26551918
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 90109291 Expired - Fee Related CN1025224C (en) | 1989-11-16 | 1990-11-16 | Cold-rolled high tonsion steel strip having excellent stretching and folding properties, and molten zinc coating steel strip, and process for manufacturing same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1025224C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100441723C (en) * | 2005-12-15 | 2008-12-10 | 株式会社神户制钢所 | Steel having superior impact absorbency and toughness of parent material |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE388249T1 (en) * | 2002-06-25 | 2008-03-15 | Jfe Steel Corp | HIGH STRENGTH CATAL ROLLED STEEL SHEET AND PRODUCTION PROCESS THEREFOR |
| ES2765674T3 (en) * | 2010-08-23 | 2020-06-10 | Nippon Steel Corp | Cold rolled steel sheet and the procedure for its production |
| CN102094149A (en) * | 2011-03-08 | 2011-06-15 | 攀钢集团钢铁钒钛股份有限公司 | Niobium-containing high-strength hot-galvanized steel plate and production method thereof |
| MX2017012196A (en) | 2015-03-25 | 2017-12-15 | Jfe Steel Corp | High-strength steel sheet and method for manufacturing same. |
| JP6052476B1 (en) | 2015-03-25 | 2016-12-27 | Ｊｆｅスチール株式会社 | High strength steel plate and manufacturing method thereof |
| WO2017029814A1 (en) * | 2015-08-19 | 2017-02-23 | Ｊｆｅスチール株式会社 | High-strength steel sheet and production method for same |
| CN106884119B (en) * | 2015-12-16 | 2019-03-26 | 上海梅山钢铁股份有限公司 | A kind of manufacturing method of thickness coating hot-dip galvanizing sheet steel |
| CN105925903B (en) * | 2016-04-27 | 2018-04-03 | 武汉钢铁有限公司 | Automobile cold-rolled Hi-Stren steel and its production method |
| CN106702267A (en) * | 2016-12-19 | 2017-05-24 | 武汉钢铁股份有限公司 | Iron-zinc coating steel plate with yield strength being 350 MPa grade and production method |
| CN106521341A (en) * | 2016-12-19 | 2017-03-22 | 武汉钢铁股份有限公司 | Iron-zinc coated steel plate with yield strength being 450 MPa and production method thereof |
-
1990
- 1990-11-16 CN CN 90109291 patent/CN1025224C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100441723C (en) * | 2005-12-15 | 2008-12-10 | 株式会社神户制钢所 | Steel having superior impact absorbency and toughness of parent material |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1051764A (en) | 1991-05-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1204284C (en) | High-strength molten-zinc-plated steel plate excellent in deposit adhesion and suitability for press forming and process for producing the same | |
| CN100339500C (en) | Ultra high strength steel composition, the process of production of an ultra high strength steel product and the product obtained | |
| CN1143005C (en) | Steel pipe having high formability and method for producing the same | |
| CN1183268C (en) | High tensile hot-rolled steel sheet having excellent strain aging hardening properties and method for producing same | |
| CN1145709C (en) | High tensile cold-rolled steel sheet having excellent strain aging hardening properties | |
| CN1265013C (en) | Steel sheet hot dip coated with Zn-Al-Mg having high Al content | |
| CN1039723C (en) | Continuously cast slab of extremely low carbon steel and thin extremely low carbon steel sheet in which surface defect rarely occurs during steel sheet manufacturing step, and method of manufacturing. | |
| CN1101482C (en) | Steel sheet for can and manufacturing method thereof | |
| CN1188534C (en) | Hot dip galvanized steel plate excellent in balance of strength and ductility and coated adhesive and its manufacturing method | |
| CN1128243C (en) | Cold rolled steel plate with excellent machining homogenity and its production process | |
| CN1547620A (en) | Steel plate exhibiting excellent workability and method for producing the same | |
| CN1247809C (en) | Coating baking hardening type cold rolled plate with good ageing resistance and its manufacturing method | |
| CN1860249A (en) | High-yield-ratio high-strength thin steel sheet and high-yield-ratio high-strength hot-dip galvanized thin steel sheet excelling in weldability and ductility as well as high-yield-ratio high-strength | |
| CN1662667A (en) | Titanium-added ferritic stainless steel sheet and production method therefor | |
| CN1856589A (en) | Hot rolled steel sheet for working | |
| CN1025224C (en) | Cold-rolled high tonsion steel strip having excellent stretching and folding properties, and molten zinc coating steel strip, and process for manufacturing same | |
| CN1934280A (en) | Cold rolled steel sheet and hot dipped steel sheet with superior strength and bake hardenability and method for manufacturing the steel sheets | |
| CN1060115A (en) | Be suitable for making the aluminium alloy of jar | |
| CN1273632C (en) | Super formable high strength steel sheet and method of manufacturing thereof | |
| CN100336930C (en) | Steel sheet for container and method of producing the same | |
| CN1303244C (en) | High-carbon hot-rolled steel plate,cold-rolled steel plate and making method thereof | |
| CN1809646A (en) | High-strength hot-rolled steel sheet excellent in shape fixability and method of producing the same | |
| CN1043905C (en) | Continuously annealed and cold rolled steel sheet | |
| CN1078911C (en) | Steel sheet for double wound pipe and method of producing the pipe | |
| CN85108620A (en) | Be suitable for the cold-rolled steel sheet and the manufacture method of enamel coating |
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 | ||
| C15 | Extension of patent right duration from 15 to 20 years for appl. with date before 31.12.1992 and still valid on 11.12.2001 (patent law change 1993) | ||
| OR01 | Other related matters | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |