JPS5947333A - Production of high-tension cold-rolled steel sheet having good drawability and aging resistance - Google Patents

Abstract

PURPOSE:To obtain a high-tension cold-rolled steel sheet having good drawability and aging resistance, by hot-rolling a steel slab having the specific compsn. contg. C at an extra low rate and having regulated B/N under specific temp. conditions then subjecting the slab to cold rolling and continuous annealing. CONSTITUTION:The steel slab contg. <=0.0040wt% C, <=0.60% Si, <=0.80% Mn, 0.035-0.15% P, 0.008-0.090% SolAl, 0.0005-0.0050% B, 0.0010-0.0050% N, 0.2-1.0 B/N, and the balance Fe and unavoidable impurities, and contg. 0.002- 0.02 total of >=1 kinds among Ti, Nb, V, Zr according to need is heated to <=1180 deg.C. The heated slab is hot-rolled at 680-830 deg.C finishing temp. and <=650 deg.C coiling temp., and is then subjected to cold rolling followed by continuous annealing. The high-tension cold-rolled steel sheet having excellent drawability and aging resistance is effectively produced by above-mentioned method even if the finishing temp. for hot rolling is the Ar3 transformation point or below.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a high-tensile cold-rolled m-plate having good drawability and aging resistance.

Conventional box annealing is used to manufacture square tensile steel sheets with good drawability, but the box annealing process requires several days for the process, and the coil state is 1-! t. 8. Heating and cooling speed in the radial direction of the coil due to heat treatment. This makes it difficult to maintain a uniform material gain over the entire coil.

By continuous annealing method h. For example, the box annealing method has the disadvantages of the above-mentioned drawbacks. However, it is possible to perform the box annealing method, but on the other hand, it involves rapid heating and rapid cooling.

Due to poor growth of crystal grains and insufficient precipitation of C, which is present in the 4C solid bath, the hardness is tL, which is required for high tensile strength steel IV. The tensile strength of -1) is relatively easily achieved. Although it is usually inferior to products made by box annealing method VC in terms of drawing properties and aging resistance, the continuous annealing method eliminates the above drawbacks. Countermeasures have been disclosed. For example, CM is 0.01
~() 1% aluminum kill R) P as K reinforcing element
, Mn, Si, etc. are added to the steel at 615°C, and during hot rolling, the growth of crystal grains in an orientation favorable to drawability is promoted. power)
Continuous annealing in progress! 6! , Tsukasa after cooling -300~5()0℃
By carrying out over-aging treatment in the eddy electric range for several seconds to several minutes, the undeposited solid solution C(7) 11. 1-11? A method for promoting ζ-strength and completely improving aging resistance has been disclosed, but 1-11? Shinamaki J8! As a natural result, this results in a complete decline in pickling properties, and the drawability and aging resistance are still inferior to conventional box annealed materials.

In addition, since the main reason for the deterioration of the aging resistance of continuously annealed steel is the large amount of peripheral C, ultra-low carbon steel with a C content reduced to less than 0.0050% is used in plain 4A etc. There are also ways to improve aging resistance. However, in the production of drawable steel sheets, it is generally necessary to finish the hot rolling at a temperature above the transformation point, and the ultra-low carbon 4$■ mentioned above is not advantageous in terms of aging resistance. Yes, but +
Since the A r B transformation point can be raised, Ar,
In order to complete the indentation finish in the γ range above the transformation point, VC is
This inevitably involves an increase in the heating temperature of the bare slab, which necessitates a complete change in the hot rolling reduction schedule, which is a bigger disadvantage than the energy saving aspect.

Another cause of deterioration in the aging resistance of continuous annealing is N dissolved in the steel. As a method to reduce the number of baths, aluminum guild steel slabs can be hot-rolled to a finishing temperature and fixed as A, or aluminum guild fA IF, 2 Q to 5 can be used to avoid deterioration of pickling properties due to high-temperature winding.
(1 ppnl (7) [3y added 2,) 3 N, 7 fixed N, hot winding to 1 V (I also know of a method to obtain the same quality of aging resistance)'1. ing.

Like this, solid? i′(C,N [j) Improving aging resistance and improving drawability and ductility. C is (1, A high-strength cold-rolled steel sheet with excellent aging resistance.
At present, it is difficult to conclude that the t:l hot J[finishing temperature is extremely high temperature] method as an I force-building method.

The purpose of the invention is to overcome the drawbacks of the above-mentioned prior art, and to provide an inno [next A
r, weird! τl manufactured at temperature 1) above the π point
Same level as t% tensile steel plate or more than that L) Immediately 5
What is the effectiveness of high-strength cold-rolled steel sheets that have both drawability and surface aging properties? ! to provide a method of construction.

This object of the present invention is achieved by the F-2 invention.

The gist of the first invention is as follows: C: 0.2 at a weight ratio of 2. (1040% odor, bottom, S
i: 0. (i 0% or less, Mn: 0.80% or less,
P: (+, (135~0.15%, 5o7A/
', : 0.008~O,(+9 (1%, B:0
．． 0005-0.0050%, N:O1](110-0
．． 0 (including 150% and B/N = 0.2-12
1801: After heating to the following temperature, hot rolling is carried out at a finishing temperature of 680 to 830°C and a total coiling temperature of 650°C or less. This is a method for producing a high-strength cold-rolled steel sheet with good drawability and aging resistance, which is characterized in that the hot-rolled stud is then cold-rolled and then subjected to continuous annealing.

The gist of the second invention is as follows.

That is, in addition to having the same basic composition as the first invention, K.

Contains 0.002 to 002% in total of any one or two or more of KTTi, Nb, V, and Z, and has B/N = 0.2 to 1. Of, remaining?f1
5 If Fe and Iit impurities e *
L and k(1, εεkunltH and fX-'
? ! + Signs of drawability, button aging condition σ) Good high tension cooling ÷
It is made of 1Σ steel plate and has 1 method.

The inventors have obtained a large number of ′p! ：Experience・Φ;1〕Result I
Regulating the component range of C113 and N1. Historically, there is no possibility of deterioration of warpage resistance and aging resistance.
: Adding 1,000 P and Si as elements (Using ultra-low carbon aluminum killed tsuba top location, slab heating temperature) W and Netsumyosu matter Naramasa ν Koshu combining V, Ar during hot rolling, 4 states J
Low-temperature finishing at the bottom, continuous H even during low-temperature winding! “Li tun υr
So, is it a squeeze? It was discovered that the cold-rolled steel plate had good aging resistance and good strength, and was completed on Thursday.

Honzai-Mei details III Narahi (ζ limited reason 5I)
The following description is based on the results of an experiment conducted by Meisho et al.

The experiments conducted by the wood inventor 'Toki are C, A, N, 13.
Each one containing fan such as ge・SυC [7, and P ()
Addition of Lf in the range of 07 to 0()8% (one small 61F block made in one room and rolled in one block to a thickness of 30 mm), heating source for each slab; W and hot rolling finish. Temperature scale: 2.8 mm (σ) at 530° C.) A hot-rolled sheet is heated immediately to 530°C, charged into a furnace, held for 2 hours, and then slowly cooled in the furnace. went. Then after pickling 0.8 vm
After cold rolling, each sample was charged into a fluidized bed heat treatment furnace at 800°C, heating rate was approximately 50°C/'sec Vc, and after the plate temperature reached 800'C, it was held for 15 seconds, and then cooled. Approximately 2 (1.0%σ after continuous annealing with rapid cooling at 1℃/see) Ta.

Experiment I rl'('-fN', C in ratio: (1,0024%,
I\in: 0.46%.

Si: Q, 21%, )': O, (171%, S: 0.0
11%, At: 0.040% standard composition, coil
- to N: (), OOI D~O, (+ (+ 8 (
1%, L(: 0.0
The slab is thnn thick and the slab heating temperature is 1100℃.
Hot rolling was completed under the conditions of a finishing hot rolling temperature of 760°C and a coiling equivalent temperature of 530°C, followed by cold rolling and continuous annealing according to the above steps [and the material properties of the test materials were adjusted. Figure 1 shows the aging index (hereafter 1.-8, 1.
11. Figure 2 shows 13 and Nσ)p
, the change in 7 values due to the
The letters are jl-A.

1, and 61.115 of Hui Hr-r? The value is Z.

Agency Fu~, Kohiki, Lano・11 (Tensile strength of test A 1i1:
It was within the range of 38 to 42 yen/- for Il gobe.

As stated in
As the scale of sex, it is) 1, t1 to 7, and (), ノ\,
14.・I used A, I.

H-7.5% of the plan is given yt th I (+ (
1℃-c: J, (1 minute increase of 1 yield stress [11 points), A,
1. ≦31・ri/J V O L is Moetano L resistance r
It is equivalent to one box annealing and the aging at room temperature can be almost ignored.A.1. ≦, 41(ri/- i!f+, also in the tλI, [Il1 effect progresses 0''slow,'-51
Since the blade l11 temporary immensity does not become h1[1, i・;t A, t, ≦4, /-ke groups j, I, q were set without experiment. , and τ11r:', r, which shows the resolute 1-ton meeting, is the in+t Il for drawing which is made by the conventional Shun ware 911,
'? Effective trading power white 4JV! 7 value ≧ as equivalent to
1.3 with Yuttei and 1. Ta.

In Figures 1 and 2, I1''J1 is also Δ, I3.C.

1), E range IJjl [Sono'1. ('
ft A, I, ≦41<g/-1〒≧1.3, which is a good range of aging resistance and drawability. So, in Figures 1 and 2, l, -te, Izu force, also W gent A B id
T3 / N = 0.2 k Indication L, +i'j
Conclusion 1. ) indicates E Id B /N = 1.0, and B
Point C, which indicates the lower limit of
H' O, (1 (105 ~ 0゜0 (61 of 150%)
1) It was found that the following should be limited.

Dimensions. This 1. The corresponding lower limit of N is 0.
0010%, A at the upper limit, 0.0 at 14 points. (1050
%, so the N content is 0.0010~0.0 (1
It was found that 50% π limit χ pi should be used7. In addition,
Lower bound to &,I' than the current l'M M4 technology point
As is clear from Figure 2, when the N content exceeds 0.0 (150%), the growth of crystal grains during annealing is significantly inhibited. 13
Is it less than a million yen? Because it significantly reduces the
vl For this reason 0.0 (l ] (1~f), 0
In order to further improve the drawability, N should be limited to a range of 1,0040% or less.

Regarding the above 13 scenes, the total addition of (1,00 (15%) is required at least) to achieve the effect of adding (3).

rI 1r-t ]% Ujff Annealing Ronoji 1 [Surface S effectiveness IF i';Q ) i N k Fixed 1. .

The crystal grain size J57C) when π formation is known for 1.3N is 11v7 (π is also effective) because the suppressing force is very small. t)
-)i'+ru. flf of grain growth of this baked σtun 11 catties
f Go If;
Although it exceeds 1%, t 13 / N 1
．． 0 kLL'li, Rl) 13 IN i jvr
1 solid i'ffLT ++ increases 孭 dull moe crystal 4) 7
．． I, 1li-+ becomes stiff and becomes 〒'fr, and the good material t1 cannot be removed. Dimension [3 / becomes too small and IJ from 02 (when it becomes I1 effect OJ" + appearance 7
) Te pole>': RI' is small 2. It has no effect on the direction of 4'1' aging, so wood) 1'
1, &j at the gate: I(/' N(1, +7 of 2-10
・5i was limited to Pekai.

In addition, the N that remained without combining with So-13 when heating the slab was
When heating the slab, there is no harm to the properties of 1nlj' H4H shoes due to the difference between υko A/- and t (and σ precipitated by A7N and 12).

The reason for limiting U, N, and l-3, /N in the present invention was explained by referring to Aζ- in the present inventors' actual results.

Regarding other components, the reasons for their limitations will be explained based on the experimental results of the present inventors.

5otAt: At requires at least 0.008% to fix N that was not fixed by B. (2 but.

A7' (14 When excess bτ is added, A that exists in a solid solution state
t increases, and grain growth during annealing becomes significant.
The upper limit i is 0.090% since it completely deteriorates the L drawability.
It was limited to 0.0 (18 to 0. (190%).

C: C is an effective element for improving the strength of the steel, but if it is included in large amounts, it not only suppresses the growth of crystal grains in orientations that are advantageous for drawability, but also forms a solid solution in the steel. Aging resistance deteriorates significantly, so the less the better! R'z
(1,0040'/, ,!: Shifujka, art
1. A range of 1 (1,00.3()% or less).

Mn: Mn is also an effective element for increasing the strength of the core.

If the amount exceeds 0.80%, the drawability will deteriorate, so the upper limit was set at 0.80%.

As is clear from Experiment I, P is the most stable element that allows the strength to be increased without deteriorating the drawability. Therefore, in order to achieve a tensile strength of 35 kp/- or more, which is the objective of the present invention, at least 0.035% is required. However, since excessive addition of 1- causes deterioration of weldability, the upper limit was set at 1-0.15%. One of the features of the present invention is that a considerably large amount of P can be added →4. It is possible to produce a high tensile strength root having a tensile strength of /ya and having good drawability and aging resistance.

Sl: Like In, Si is an element that is effective at increasing the strength of steel, t+sl, but (1,60%2.-d:+lJ
Since it causes deterioration of the aperture, I limited it to o, 6 o LA or less.

S: Contains S = M: K and Tj are not particularly limited, but it is 8:0 in the range where V remains unavoidable in the usual washing process,
C12 (il at 1% or less does not adversely affect the objective coupling of the present invention.

The above-mentioned tensile force as the object of the present invention) 1 degree 35~5 (l
Explanation of the reasons for limiting the basic composition of steel to obtain high tensile strength cold-rolled steel sheets with drawability, aging resistance, and instant strength after ensuring all kg/- [-However, in order to make these limited components effective, The heating temperature, final rolling temperature, and coiling temperature of the steel slab, which will be explained below, have a significant influence on the heating temperature, and the above hot rolling conditions are particularly appropriate for N and IJ effective materials of ultra-low carbon steel slabs. Since the effect can only be achieved when hot rolling is carried out, these 2y hot rolling cases will be explained below.

Regarding the warm heating of the first slab &,t,;σ↓′Hatakeσ)
It is necessary that the heating temperature be 1180°C or lower, which is lower than the slab heating temperature of 1250 to 13011'C. The reason for this is that BN does not dissolve in this one grade range, and 13 is considered to have a fixed heat with the total amount of BN. koσ)
This is because the temperature IW range has a favorable influence on the growth of crystal grains during annealing, and is also necessary for fixing as AtN due to the remaining N = i At fixed as BN. To the limit of slab heating temperature! Limited to 1 piece 2
2, but the rolling property σ) point is 95 (desired to be 1°C or higher).
1F, <1 of the present invention []]
The heating temperature of 160° C. is t1″+kabura.

D, Vpy ~ extension - F, +7 + M W k 68 (
1 to 83 (1°C) range vr limit M L, the reason will be explained and explained.

Conventionally, the aperture value plate 11.゛nozo6τli;, m +=
-r i, i, hot rolling in both the box annealing method and the continuous annealing method, with a vortex layer above the hot rolling radiance fAr3 inflection point, that is, all 3-stenite J'Fj), (γ phase) It is said that it is desirable that the heating end temperature is Ar, and the transformation is less than % ferrite (α phase).
In the two-phase region of 1-austenite (γ phase), if the 5-phase α region is r-n and the ζ-layer end-r is used, it will be disadvantageous for drawability (J 1 (
1) and (] On ) orientation develops parallel to the plate surface (7
This is because it was known that during annealing, the h(111) direction, which is advantageous for politics, inhibits the formation of heat parallel to the entire plate surface.

This #1. In contrast, the present inventors conducted experiments H that circulated since Vrc to create the specific Hg11 formation according to the present invention.
The growth of crystal grains during annealing in the plate, the (111) orientation is parallel to AFi.
It has been found that a temperature range of 680 to 830 DEG C. is extremely effective.

Real; frugal ■ C: 0. O (116%, Mn:Q, 41%, S
i: 0.48%, t': o, o76%, S'0.0
16%, A/-: 0, (121%, N: 0.0037
%, B: 0.0 (129%, B/N = 0.78) A small lump having a composition of After heating, the finishing temperature was set to 650 to 930°C to form a hot rolled sheet with a thickness of 28 gates, which was then charged into a furnace at 530°C, held for 2 hours, and then cooled in the furnace, which corresponds to low-temperature winding of a hot rolled sheet. One treatment was carried out for some of the test pieces.After finishing hot rolling for visual comparison,
A hot-rolled sheet was charged into a furnace at 80° C., held for 2 hours, and then cooled in the furnace, which was equivalent to high-temperature winding. The steps after pickling were the same as the seven general experimental steps of the present inventors described above to produce a cold phase by continuous annealing. The results are shown in Figure 3 (A) and (13
As shown in 1. In Fig. 3 (5) and (B), the ○ mark indicates that all winding was performed at a low temperature of 530 °C, and the × mark indicates a high temperature winding of 680 °C. L? 1 roll 4 rows of ivy; h
Zl. ;7), Figure 3 (A), (Ill, 1: Reveal), t! Crystallinity 68 () ~ 83
(If it ends at 1℃, 43 degrees) λ Very good q ``It turns out that this is an example.
General V for &'s 11.4 building? Hot-rolled finish 17Ar, σ1 above the transformation point! This is a great effect of the present invention, as it breaks through the conventional 'l'i'+ convention, which required that it end with tjB:2.

Slightly lower, but with high tension 'l A5v ltl pν
[Ice core Z, 35 kri/- or more] Satisfied, in the present invention, hot rolling process: 680 to 83
(JJ was determined in the range of 1°C.

This an < lrg fixed low 6 information l' L nln
Out-IFj'1. The reason for the addition of Jt-7 to T I'1 is obvious (although it is not J, hot rolling is sometimes carried out using Ar, low llI, Xl below the transformation point, There are also 7 works, Mino, and LI.
, lX remains unchanged σ) even after it reaches room temperature,
In addition, by lowering the slough heating temperature to 1180°C or lower, which is lower than the conventional method, the 4-1 outputs of r3N, A, etc.
-) Since it is made into one person, the synergistic effect of these increases the squeezeability by 1/r.

Next, regarding the hot-rolling temperature, when we compare the case of rolling at 530℃ and the case of rolling at 680℃, there is a slight deterioration in the tensile strength of the latter. The T value is 700 degrees Celsius, so if the temperature is 700 degrees Celsius, it will be slightly -1. , 8 (v1 in the case of 1 still 1 in extension to -1 of 10℃
680-83011 which shows a slight tendency to deteriorate? It is thought that there is no change in the hot rolling finishing temperature range of . On the other hand, the descaling cost during high-temperature winding and transportation is 91 to 1.
f-Now. In contrast to this (7 In the present invention, Ar is the transformation point υ,
77+ in the lower i-crystal, 2/2: Even if it is rolled at a lower temperature with the riko and V, it is the same as the high-temperature rolled material, but in RJClj 8, there is a tendency in the opposite direction. The upper limit of the amount of dust per hot-rolling vortex was set at 65°C (1°C) because it has the effect of reducing pickling costs.

Next, in addition to the above-mentioned composition according to the present invention, 'j'i.

If you switch from among Nb, V, and Zr, it will be Zuo L or 1.
Ochumori, < is 0.00 for 2 or more sticks in total Fl"l'
2 to (contains 102% and 1.3/N = 0.2
~1.0 and Z) job matching and other hot rolling requirements to 11
Same as Section 1 -Ii'<' -t Z,, From Kotakumi, the effect of the present invention 47+-ke -J1'('Il[Lii (one thing to do; I7. Town name fruit!'r' Since I was able to confirm r and C2 by Q Ill, I will explain and explain this 9π.

``211・(111 Real 1';ti'l's basic composition and L, ・'Color 1 As shown in table] 1ffTi, N13.V, lr's p,
lBj, f addition [Tasuke! ℃ air melting V trowel 11. Q
In a small room, the slab was made into a small 1 "l block office location 'j'! L/, same as above, 17 r, 30 questions). , finishing temperature 78 (1℃, 2.8 rrml, + heat I
#, 4i (Toshi, 13j Chik 5301) was charged into a furnace and held for 2 hours with backward tilt + 1 stomach 1). After pickling? The process for wheat is the same as in Experiment I, ■J). 9] 1 comb - [!
1.(lcj is as shown in Table 2).

r, J'+ It is clear from Tables 1 and 2 that Ti like the sample Soma 3 as shown in λ: 0.002 'A kr TeC (
/') Ik1 ratio 'l'i /C=021 L
The addition of the carbide forming element τ in A and 1. This shows that only the value decreases in No. 21, and that it is possible to obtain a material that has good aging properties and is suitable for manufacturing shoulder plates.

Also, what about the sample material 2? lJ <'l'i : O, (l
o j fitting r value of 1% content, and A, 1. The quality is (j
Test sample (4) of the basic composition according to the present invention that does not contain ``IJ, ``ht element'' is ♀1, and the effect of addition of ``I゛1'' cannot be observed in 1 river. Not possible - JE's not possible?
It does not combine with C than Ilr, and A, I
.

It is thought that the decrease in value was due to the fact that the effect of F was not working. This tendency was observed not only in Ti but also in other carbide-forming elements such as Nb, V, and Zr.

Therefore, if one or more of Ti, Nb, V, and Zr are added together, ijA, 1. However, it is found that the lower limit y□, (1 (12%) should be set (also, Ti,
Nl).

The reason why the upper limit of V%Zr was set at 0.02% is because it was found that even this (Y-over-addition/Jl+) had no effect because it saturated the mind and was useless.

Like this, the basic composition of VC was 41 crabs.

1~l], V, Zr, 11 folds and t
Contains 0.0 (12 to 102%) or more of U2Oton, and B/N = 0.2 to 1.0, and the remainder is fJ, FcO, and small unavoidable impurities. A hot-rolled steel slab consisting of L, hot-rolled at the same heating temperature and hot-rolling finishing temperature of 1 coiling temperature is cold-rolled under the same conditions and then subjected to continuous annealing. It has become clear that the sound effects of the invention are even more effective.

As a continuous annealing strip YP, the maximum temperature of the steel plate must be higher than the recrystallization temperature, and other additions:
,1L1jlヱI! [11. 'll
Gutsu no i1ζ, pocket & detsui-Ctr, j-'1. 'fK
Limited Boku Shark (7 offices.

Implementation ff11 S・R (5'4'q (6
KANOSU, ・4 is melted, and plate thickness 2 (
It was used as a slab for the l fl gate. Koil, et al.'s test: 118 (104 below 1'c)
1 to 112 (11, ^B at 1°C for 60 minutes, then hot F7' bi T l to IJ, 7j: (Ff)
[jil ff) Finishing pressure 4+l in the temperature range of 6Hfl to 83()℃; ke 11°-17.65 (1'C
C human τ black degree 53 (+ 1?: Volume j19.su, 1j
EI'7: (, 11 coils with 2m gate.

Next, for comparison, the heating temperature of the sample GTI 444 was set at 25 (1'C and 770
*7 Jl % Temperature 1], 3. (1°C, limited to hot rolling finishing temperature)
Samples were prepared at 920°C and compared with the comparative example (7.
Altj: This is an unspecified sale. Thus, Tokuko fever has 11 valent 1 stopper p, 1 valence of 1 and 1 enemy - Y11, 44 of 53 (1℃
After winding with &τ, it was acid-absorbed under the same conditions and then cold rolled I7. Hikii: 〒、ki；１】４耘６）、r4 God was given. Continuous annealing conditions: 1ri force to 1Σ mouth is approximately 211
'C: / Sec, soaking is 8 (l fl ℃ for 20 seconds (41: 'I"I' * (t; power fact 11j
'-i1 is approximately 5 +1 °C/sec. 0) 06
% +8'Al 'I' (HaniM, k /7illL
, ft.

Did you get it from hiding? 'l) The 5th Rebellion Cτ Part 1 Part 1
-Ji5j Mechanical property 'I'1 and T value,
, to ■. I1 White Il-' 11 River 5
Pi shi /komu,'i ;,: fma t 4 Ymo(((As shown.

No. 4-(pa From Table 4, it can be seen that the sample fHA1, 2.3, and 4.5 manufactured according to the present invention all have a tensile strength of 35
Is it a high tensile strength cold rolled steel sheet with kf/+IIA or higher and at the same time exhibits drawability? The value is always 164 or higher, and A, 1. The value is 4kp for sample m editions 1 to 4.
-The comparative steels of test forceps A4' and A4'', which did not satisfy only one requirement of the present invention, showed a slow aging property of 7/- or less, and flat 5 showed a non-aging property of 3 to 7/- or less. Value tit 1.
If it is less than or equal to 3, it is bad (', A, I, and the value also exceeds 4/π4, and 5 cold rolling with excellent drawability and aging resistance is achieved only when all the requirements of the present invention are satisfied. It shows that you can get steel plate.

In addition, after giving a 2% tolerance to the above-mentioned sample material AI according to the present invention, 2, 3, and 4°5, the work hardening meter was measured after applying a treatment equivalent to baking paint at 170°C for 2 () minutes. Not including 3
A significant increase in the yield point of ~5 ky/yaJ was also observed. This shows that the sinter hardening ability (B1 (quality)) is also extremely excellent.

- As is clear from the above examples, the composition of the steel of the present invention is limited to 13. N and B/N rules
Ii[7, and suppress the slab heating temperature to 1180℃ or less, low γ1 richness11tllt, , finish rolling temperature total 68 (
) ~ 83 (1℃, the winding temperature is regulated to 650℃ or higher 1゛・1 pressure ii 1: After the f row is completed, 1 normal cold pressure is applied, (, after that, a series of rapid cooling is applied. By performing 1-1 annealing, the tensile strength increased to 35 to 50/
Va, and the f value is 1.3 or more, A, 1. Non-aging 1 with a value of 3kf/- or less at room temperature (- or 4 to 9/-
The following high tensile strength cold grinding g4 plate (47), which exhibits dynamic l and excellent drawability and aging resistance, can be used as a high tensile cold grinding plate for various presses. The immediate effect was felt by the samurai.

[Brief explanation of the drawing]

Figure 1 shows the aging index (A, I, value) of the present invention.
1-diagram showing the amount of N'Dr I and the influence of 13/N, ii) 72-diagram! c, t +-ii+! Figure 3 (A>, (I3) shows the influence of [3,N and 13/N in the steel). ．This is FOIIIZI which shows the relationship between the JX cardiopulmonary (i' S) and the paralysis value. Proxy Nakaji 2 n (= Figure 1 B (%) Figure 2 Y Directional B (%) 11. 3 Diagram Heat Moxibustion 1 Ishijo Shijo L ('C) Procedural Amendment (Method ゛) 1981 - December 10, 1982, Commissioner of the Japan Patent Office, Mr. Kazuo Wakasugi, Incident Indication + 1fJfU 1957 Patent & 1vJ157J
7' 6 No. 2, Name of Hatsuyu J Method for producing high-strength cold-rolled steel sheets with good drawing resistance and aging resistance 3, Relationship with the supplementary case Patent applicant address Chuo, Kobe City, Hyogo Prefecture 28, Kitahonmachi-dori-chome, Ward Name (125) Kawasaki Steel Co., Ltd. Representative: No. 7 Yagi No. 4, Agent Address: 187 November 12, 1980 (Shipping date: November 30, 1988) ) 6. Number of inventions increased by amendment 6. Drawing subject to amendment 7. Contents of amendment as shown in Attachment Figure 3 (5). that's all

Claims (2)

[Claims] (1) C in weight ratio! 0.0 (14 (1% or less, Sl; (1,60% or less, Mn: 0.B □% or more T', P: 0.035-0.15%, sat A
t: o, (1(18~Oo 9 (l z, B
: 0.0005~(1,0050(X;, N:
(Ill 01 (1~(1,0050% included, and 137N = (1,2~1.(), the remainder is Fe
and steel nulab' (
After heating to a temperature of 1180°C or lower, hot rolling is carried out with a hot rolling finishing temperature of 680 to 830°C and a total coiling temperature of 650°C or lower.1st, the hot rolled steel sheet is cold rolled and then continuously annealed. A method for producing high-tensile cold-rolled m-plates with good drawability and aging resistance. (2) C by weight ratio: 0. (1 (14+1% or less, Sl: 060% or less, Mn: 0.8 (1%
Itcho 11: o, 035-0.15%, 5o7
At: 0.008-0.090%, B: 0.0005
~0.0050%, N: 0.0 (110~
00050%, fK 'I'i, Nb
, V, Zr at a total content of 0, On2 to 002%, and B/N
= 0.2 to 1.0, and the remainder consists of Fe and unavoidable impurities. After heating the steel slab to ], ] 8 (temperature of 1°C or less), the hot rolling finishing temperature '(i-680 to 8
3 (Ic, complete hot rolling with a coiling temperature of 65 (1°C or less) 1) Then, the hot rolled n1 sheet is subjected to continuous annealing after cold rolling. A method for producing a high-tensile cold-rolled m-plate with good strength and aging resistance.