JPS5931828A - Production of steel sheet for enamel having excellent formability - Google Patents

Abstract

PURPOSE:To produce inexpensively a titled steel sheet having good quality, by casting continuously a dead soft steel contg. Mn and Ti at the amt. of addition controlled in such a way that the effective Ti satisfies specific conditions and subjecting the steel to recrystallization annealing after hot rolling and cold rolling. CONSTITUTION:The steel contg., by weight %, 0.002-0.006% C and 0.01-0.10% Mn and is incorporated with Ti at the effective content content Ti* of Ti expressed by the formula I in a way as to satisfy the formula II is continuously cast to a continuous casting slab. The continuous casting slab is hot-rolled at <=780 deg.C finish hot rolling temp. The hot rolled steel sheet is cold-rolled in accordance with a conventional method and is then subjected to recrystallization annealing at the recrystallization temp. or above and <=1,000 deg.C as it is or after Ni plating is applied at 0.1-2.0g/m<2> on the surface of the cold-rolled steel sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a steel plate for enameling that has excellent formability, and in particular, a steel plate for enameling that has excellent press formability and adhesiveness that can be formed through continuous pressure casting. This paper proposes a manufacturing method for .

Conventional high-grade 11 steel plates for brazing are ingot-formed with Cag F steel. Open annealing method after rolling [Thus decarburization annealing, C
01) It was produced by reducing the temperature to pm or higher. 1. The high elemental content of the steel (200 ppm, 1 clay) makes it 1 day resistant to scratches after firing. It is in. In addition, the reason for adopting decarburization annealing using Omono-yaki ρII is the excellent 1t enamel forming ((1 and (1) solution of enamel properties) 2). distorted,(
Row) 2nd generation after firing means ll/1 characteristic,
In the present invention, the terms "d", "durability", and "floating property" are used separately.

, J-It was hot; 11-1 conventional 11 L]]
In the manufacturing method of the plate, rimmed steel is often used (1), and rimmed steel is often used with deep drawing. Since it is common to anneal the steel in a decarburizing furnace, continuous casting is not possible and open annealing is not possible, which increases manufacturing costs. In addition, due to the inclusion defects and segregation that are characteristic of Samurai ingots, the quality of the product steel strip is non-uniform.
A gap occurs near the boundary between the 1st layer and the 217th layer]
- It had the disadvantage of being 7 or 4, which could be called fate.

The present invention overcomes the above-mentioned drawbacks of the conventional manufacturing technology for enamel steel plates, and produces high-quality enamel plates with excellent press formability from continuous steel at low cost! The purpose is to propose technology for building. The method of the present invention, which corresponds to this purpose and achieves the same effect as described above, is (a) by Shigehata,
O: 0,002~o,ooo person.

Mr.: 0. O1~(1,10%, and Ti
Adjust the addition q1 so that the ffi effective titanium content Tt satisfies the conditions of formula (2) % formula % (2) and melt the containing 7't'', (b) melt the above melt. Continuously cast steel to make two continuous cast slabs, (c) and (1) continuous cast slabs, hot rolled slabs.
(1) Perform ultra-long rolling at a temperature of 780°C or less, and (2) After cold rolling according to a conventional method, either as it is or apply a 0.1-2. It is characterized by applying N1 plating of Ori 42 and performing recrystallization annealing at a temperature above the crystallization temperature and below 1000℃. The manufacturing method is '1': A detailed explanation will be given of the places where the non-invention is limited as described above.

(b) Regarding the IN component composition of accumulated fertilizer value, T1 and 0
``Rl is determined from two aspects: (1) improvement in 1-ton roll resistance and ■ 11-quality improvement, but in the present invention, 1-mill is an important element. In the pot σ) Tji-J: all combine with N, S, 0, Tj
,N, ,,.

Creates carbon/nitride of Tj, S, and TiO, and the remainder is solid solution T1
Tona Z). Then, the order of formation of charcoal/9ide precipitates in ↑゛1 is =j: -4' t R(l o ℃ly, l+ toothache, TtN, TIS are formed, and the remaining T1 is 0. Compound [7, TiO precipitates are formed, and the remaining Ti
id, remains as solid solution T1.

1゛1- There is little bleaching, and the O in the molten steel is total IT1 (3 precipitates and 1. solid 5 bits J +, -4' solid solution O remains Z), r
Since the value is not inferior, the lower limit of T prefecture is 1 from all T1 ships.
, 'iN, TiS and 1. Calculate the effective Ti (Tj'') defined in (1) 2 below by subtracting the value for Ti.The amount by which this effective titanium Ti'' satisfies the condition of equation (2) is 1. ,I'l
It must be added so that the amount is at least 4 times that of 0 nails.

Tl*= Tl −−N −−−8(+>14
82 T1*>4-, OX a (2) Also, the upper limit of T1 was set to 0.1° for economic reasons.

*For the above reasons, T'', 9S N: T1. So 4
・There is a need to control it to 0.8G or higher and 0.10% or lower.

On the other hand, 0 is o, oo! 2o~01(10(Tochiσ)) Low carbon steel .The first evening 1 is Of (1,0010~0.00QC1
Section, Nl 0.0020~0.0 (1fTochi,
S; (+, +1(15~0,01.!Schi, T
i + 0.055~0.08 (1%, Ti/O
+ 10 of Ti, C precipitates in steel plate from 4.0' to 19.5
It is a diagram showing the relationship between the jump value and the correction value. (The durability evaluation values are shown in Table 8 as described later.
We conducted a discussion on the sale, and the results shown in Table 4 were as follows.
(The decision was made after paying for the IliE Jet.) As shown in Figure 1, the inventor discovered that when the TjO analysis 1114 of course, the heavy M staff was CI, 41 laps before 01, there were many jumps. etc. were found out.

Since the 1-1 analysis 11'' direction is determined by the existence of 1-ro IJ5 and a R1 as described above, the total amount of this 1-10 precipitate is 0. In order to precipitate LJ, L2, the following formula (8) requires 4' (1, (1(
It is necessary that C of 12 inches L and J- be included in the steel.

Next, talk about the upper limit pressure of 0. Figure 2 shows CM and r
Indicates the relationship between values, but Is! As you can see from I, Ol
it is 0. Non 91i super root, C is all ffl,
TtO 1. ．． It has been confirmed that the r value does not deteriorate to jh and r'Wt even if solid solution C is not present in the steel. Therefore, CI'll &,3,n,ooz
~o, t+no Z limited.

Figure 8 shows the relationship between the river and O star. 1 with diagonal lines in the diagram
111 minutes is the appropriate range for the ineffective ditan T1'' and at0Mn weight ratio; Mn is usually added with S to prevent hot brittle cracking. However, in the case of T1 killed forging, solid solution S is fixed as J'iS and hot brittle cracking does not occur, so Mn can be lowered.

In the case of ordinary low carbon steel, the hot rolling finishing temperature is A r a
If the temperature is below the transformation point, the r value will deteriorate extremely, but in the case of T1 killed steel, In (f), 1. OcIj, even if the hot rolling finishing temperature is 780°C or lower, r
The value does not deteriorate.

Regarding the lower limit of In, it is industrially difficult to make it less than o, o], 1, so the lower limit is specified as (1, (11,%).For the above reasons, Mn is 0.01 to 0. , ]
, limited to 0chi.

(b) Continuously cast molten steel having the above-mentioned composition to create a continuous cast slab.

The conventional steel sheet used for dipping has a low 0 (0 = 0.04%
) High oxygen (oxygen-containing paper 450p1') m) was used. Therefore, when casting is hesitated, 9 in the molten steel reacts,
Since 00 gas was generated (rimming reaction), it was not possible to produce the product by following the procedure of i2. In comparison, the method of the present invention utilizes precipitates such as TiO as a hydrogen storage source, so it is possible to continuously control zero to the extent that the 111 siliming reaction does not occur. It is now possible to perform casting.

(c) Next, the reasons for limiting the hot rolling conditions will be described.

/l-Invention (low carbon Ti/guild steel has less Ti and 0 content compared to conventional TIW steel), so it is difficult for Ti(+) to be produced during hot rolling. Therefore, the hot rolling conditioning temperature should be kept below 780℃, α
It is necessary to carry out hot rolling in order to promote the precipitation of TiC, but also to improve the crack resistance.

Generally, when the hot rolling finishing temperature falls below the A,rs transformation point, the r value deteriorates to the edge of the frame.
By using a T1 guild pot with a low shear of 01 (lower than 1) and ultra-low carbon, we manufacture a steel plate 5c with good drawability (7 value) and elongation (r): (El)). I want to be able to do that.

For the above reasons, the hot rolling finishing temperature is specified to be 780°C or less.

(→　Next, I will explain the tips for annealing after cold rolling.

If annealing is carried out at a temperature below the recrystallization temperature, sufficient workability will be obtained. Using an annealing furnace, the ciIT crystal temperature is lower than 2, ], (100
℃ or below] for 5 seconds or more.

In addition, prior to the above continuous firing (tun), gold RN1 was applied to the cold-rolled sheet in advance.
When plating the surface [+] and the edge 42 to a thickness of -2.0'4", it will adhere well without applying pre-filling such as pickling, N soil demolition, etc. 1-1: In this respect, conventional steel sheets for enameling require pretreatment such as degreasing, pickling, water washing, and N1 flushing before being enamelled.

In short, pickling d is performed to activate the steel plate surface and improve the adhesion between the wax layer and the steel plate, and the pickling N1 flash improves the adhesion and improves the adhesion of T9 (> (z% at the time of formation). 1
This event is held for the purpose of the 12th Daijinboichi.

However, if the surface of the blind plate is annealed and Ni-plated in advance as in the present invention, it is possible to form a 4y1q on Qi at the waxing stage without performing all such pre-treatments.
It has been found that good adhesion can be obtained at about q.

Especially for the purpose of degreasing, cold-rolled sheets are heated to 40() to 5()0℃.
By heating the steel sheet to a temperature of 18' to burn off the oil and fat adhering to the surface of the steel plate and generating a thin scale sound of 17 V, extremely excellent adhesion can be obtained.

1,000)Limetsuki elbow d1,fl, ], fOy7, If the effect is less than 2, the effect will be reduced to 1n, and 2, Oy7. ,
, S or more requires the installation of thick plating equipment on the entry side of the continuous U11 annealing furnace, which is not economical. For the above reasons, 0.0. ]~2
．． 0 phi was set at 11.51.

Next, embodiments of the present invention will be explained.

Implementation f II 1 The component composition within the scope of the present invention, which is acceptable for Rock-1, is 0.
The comparison is 1・I,! (2) Molten steel with a composition outside the range of the present invention was made into a continuous cast slab, and hot-rolled as shown in the table at a rolling temperature of 8.2 pJ days) 71 days. Then, it was wound up at a winding temperature of 050°C. The hot-rolled roots were then cold-rolled to 0,7 mm [7, then 820 °C
Continuous annealing was performed for 40 seconds. After annealing (1, 4, Sugin pass rolling process, mechanical properties, dimension jump test M1 was conducted. Mechanical properties were investigated in the rolling direction) 7, 00
For the 8 directions of (L), 450 (D), and 90° (0), No. II85 test pieces were prepared and tensile test was carried out. 1, and measured the yield strength, tensile strength, elongation, and r value in the L, O, and D directions (each L10+2T), and the average value of each indicated by □21 -2.

1, 1 jump test@, for each sample, table -
The enamel treatment was performed on all samples under the pretreatment conditions of 8 conditions as shown in Table 8, and the presence or absence of sagging under each of the conditions I, I+, ]TI was investigated. I,
For II and III, all items with no jumps are marked with an ◎ mark, and those with 8 sales cases where jumps occurred are marked with an X. 〇Table-4 Example ∎ A cold-rolled coil of the invention steel A shown in Table 1 (1, 8+l+, 7
After cold rolling to 7+, the surface of the steel plate is Q, 49. before continuous annealing. An” N1 eye @fc applied, 8 ru 0℃ x 4
A coil was made that underwent recrystallization annealing for 0 seconds and a coil that was not subjected to N1 plating.
Bake for 1 minute at 00℃~flO(+'C,
After the interview, 88 (1℃ x 4.5 minutes of baking was performed, and then the adhesion index (P, E, I) was measured using a PEI tester.
ff, I looked into it.

The results are shown in Table-5.

Table 6 As explained above, according to the present invention, it is possible to provide, at a low cost, a steel plate for enameling that is excellent in strength, flexibility, adhesion A+, and mechanical properties from steel that has undergone continuous casting.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between TiC output and jumpability evaluation. However, the ranking of jumpability is shown in Table 4. The tA2 diagram is a graph showing the relationship between O and r value. FIG. 8 shows the appropriate range of 0. Valid', ['113
It is a graph showing t(Ti*). Made by special applicant Kawasaki. Tetsu Co., Ltd. Figure 1 Ac (weight%) Figure 2 Tic (weight%)

Claims (1)

[Claims] 1 Weight: O: U, 002~l), (10(
Iji + Mn: (), old ~ +1, 10th section, Ti is the effective titanium slide T expressed by the following formula (1)? is below (2)
The f@ containing E was continuously cast to satisfy the conditions of the formula, hot rolled to a hot rolling finishing temperature of 780°C or less, then cold rolled according to a conventional method, and then the recrystallization temperature Over 10 (1iiiIli recrystallization at a temperature below 10℃)
A method for producing a steel plate for enameling with excellent formability, the method comprising: Note Ti*=T, ---N ---8, 1482'') *4.0 ×Ori'I't < 0, 10 (
z) λ weight lit %, O: 0. (102~(+
, ooo'ly + Mn 1O901~(1,
Section 10, T1 is as follows (effective titanium h1 expressed by the formula
Containing the metal so as to satisfy the conditions of formula (z) below, it was continuously cast, hot rolled to a hot rolling finishing temperature of 18°C (1°C or less), and then cold rolled according to a conventional method. , characterized in that the cold-rolled steel plate surface K (1,1 to 2.n?/'1.-) is pre-blocked, and recrystallization annealing is performed at a temperature of υζ above the recrystallization temperature and below 1000°C. A method for manufacturing steel plates for enameling with excellent formability. Notes * Ti = T1--N ---8 (:+) 1, T1. 82 4, OxO (Ti), D, 10 (
2)