JPS6067649A - Method for controlling zinc applying amount of single surface zinc hot dipping steel plate - Google Patents

Abstract

PURPOSE:To uniformize the single surface zinc applying amount by suppressing the shaking or bending of a steel plate, by injecting a gaseous fluid to the inhibitor coated surface of the steel plate drawn up from a bath, and supporting the pressing force in the side of the plating surface formed to the back side of said steel plate by a support roll. CONSTITUTION:A gaseous fluid 14 is blown to the side of the plating surface 10 of a steel plate drawn up from a zinc plating bath 12 from an apply amount control means 13 to blow off excessive adhered zinc 15. Molten zinc 17 adhered to an inhibitor coating film 11 is blown off by a flame or high temp. gas injected from a zinc removing means 19. A gaseous fluid 22 is injected from a non- contact type steel plate support means 21 to press the plating surface to a support roll 19 to support the steel plate. The shaking in a horizontal direction and the bending in a width direction of the steel plate are suppressed by this pressing force to make a single surface zinc apply amount uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a single-sided hot-dip galvanized fill plate. Single-sided melting that maintains uniformity over the entire one side of the
The present invention relates to a method for controlling the amount of curved lead.

To explain the conventional single-sided hot-dip galvanized steel sheet 1j (17 桔 method with reference to the process diagram in Figure 1, single-sided galvanized steel plate 1; i'lj
1lli lead-plated steel strip 1 bay]
Unrolled from Friel 2, pre-treatment installation 1i! f3V
At C, oil and the like adhering to the surface of the strip are removed, and at roll coater 4, an inhibitor mainly composed of water glass is applied. The strip is subjected in an annealing furnace 5 to annealing of the suittrip steel plate and firing of the inhibitor. said strip &j (i'r F 1] 1
Continuously becomes molten C in the lead-plated bathtub 6! 1. After the galvanizing process is performed, in 111- of the plating bath 6, the 77 filli lead adhering to the inhibitor coating film is removed, and the amount of zinc coating on the galvanized surface is controlled by AI. . Thereafter, the strip passes through an alloying furnace 7 and is cooled in a cooling facility 8, and then the inhibitor is removed from the strip surface in an inhibitor stripping and removal facility 9. One side is a cold rolled steel plate and the other side is This is a single-sided hot-dip galvanized steel sheet where the surface is hot-dip galvanized.

Conventionally, when manufacturing single-sided hot-dip galvanized steel sheets, in order to control the coating amount, the V directly above the plating bath 12 is
By spraying compressed gas fluid 14 from a certain zinc coverage control means 13 toward the galvanized surface 10 of the strip 1, excess 481 zinc coverage exceeding the predetermined zinc coverage is removed.
Zinc LJ ("j
hI's suppression 1 has been made.

Strip OK fJ, the fused zinc 17 sticking to the clothed inhibitor coating film is blown off by the flame ejected from the MII lead removal means 16 and the hot gas fluid 18. Zinc 1 Plating is applied to prevent the strip from vibrating in the horizontal direction and from bending in the width direction due to being pushed by the gas fluids 14 and 18 sprayed toward the strip by the thickness control means 13 and the zinc removal means 16. By sandwiching the strip between a support roll 19 provided on the side of the zinc 10 and a support roll 20 provided on the side of the inhibitor 11, the deflection and curvature of the zinc eyelid f1) are prevented in the part facing the control means 13. Therefore, Roy τth, 1
remains almost constant. However, when the slip I/slip is sandwiched between the two support rolls 19 and 20 as described above, cracks occur in the inhibitor coating film 11 of the strip that contacts the support roll 20, and this crack occurs. (If the outside air is hot) The disadvantage is that a temper color will appear as it comes into contact with the IJ surface.

In order to avoid the above-mentioned drawbacks, the support roll 20 in contact with the 1≦11 inhibitor coating film 11 is removed, as shown in Fig. 41111 of Fig. 3.
Conventionally, a device that supports only one side of the strip using only a support roll 19 as shown in the plan view has also been adopted.

The device does not cause any trouble in operation when the amount of zinc is large. This is because the amount of excess E1 zinc 15 that can be blown off is small, so the ejection force of the gas 1.1 body 14 can be weakened. However, the curved chain (-J
When the amount of gas is less than 45f/-/rn2, the jetting force of the gas fluid 14 must be reduced to JQi, and as a result, the supporting capacity of the IJ tube decreases, and the strip is affected by the fluid 14. Horizontal vibration and [
1] Is the amount of curvature uniform in the length and middle direction of the strip because it cannot prevent bending in the direction? This leads to the disadvantage that it cannot be used. In particular, the curvature of the strip in the 1j direction is large when the width of the strip is 1100 mm or more. Under the uniform and strong pressing force of the gas fluid 14, the tl of the strip
There is a drawback that there are more falls on both ends of the zinc mesh fan in the J direction. It is impossible to expect a uniform monthly 1.1 with the disadvantages of non-uniformity along the length and in the middle of the strip being compounded and covering the entire surface of the strip.

The object of the present invention is to provide a method for controlling the amount of zinc, which eliminates and improves the above-mentioned drawbacks that occur when producing single-sided lead-plated steel sheets. The above object can be achieved by providing the control method described in section 9.IJ.

That is, in the present invention, when producing a single-sided hot-dip galvanized steel plate, the steel plate coated with an inhibitor on one side is immersed in a hot-dip galvanized bath, and then the other side is coated with an inhibitor. After applying the 111 button plating, the steel plate was lifted up and a gas fluid was blown onto the galvanized surface to control the adhesion between the zinc. Lead plated value lil board sub.

In the chain +1 amount control method, t'+il Ri':
After blowing the gas fluid onto the galvanized surface of the steel plate salvaged from the steel bath IY-1, a large amount of gas is sprayed onto the surface coated with the inhibitor, and this gas fluid is sprayed onto the surface coated with the inhibitor.
The support roll provided on the back side of the QQ10 surface supports the pressing force from the njl nL2 'Zo shot! ii'l'I14 The 111 lead-plated/zinc space on this side (=I' of the hot-dipped galvanized steel plate with constant I year), the 1st lead rlH1lill
? ii'll force method V (two leaps).

Next, the present invention will be explained in detail.

The present inventors believe that the cause of the occurrence of temper color on the product when manufacturing conventional single-sided hot-dip lead-plated steel sheets is directly caused by the inhibitor coating film IJ and the support hole 20 shown in FIG. Knowing that this is due to the occurrence of cracks in the coating film 11 due to contact, the occurrence of Denver color can be prevented by removing the support roll 20 that comes into contact with the coating 1jφ11. Ta. However, it is melted on one side with a light weight! 111 lead-plated steel plate is now available, and the piece 1711 produced by the above method is melted! ■ "It is difficult to maintain the accuracy of sub-chain + 1 for lead-plated steel sheets. Therefore, the present inventors have determined that in order to maintain the above-mentioned To the position F of the removed support roll 20 on the acquisition side,
As a result of various research experiments on means for pressing the inhibitor-coated surface in place of the function of the support roll 20, we found that a gaseous fluid was applied to the coating surface 19 (=I, while support was provided on the back side of this blowing roller τJ). By providing the roll 19, the barrier 11
- The inhibitor is applied non-contactly by holding the zinc-plated surface between support rolls 19 in a non-contact manner.
19. of l expenses. The present invention was completed based on the idea that it is possible to prevent cracks and ensure the accuracy of the jtk lead chain word 1.

The invention will now be explained in detail with reference to the drawings.

FIG. 5 is a side view of the IJ tube being pulled out of the hot-dip galvanized bathtub to which the method of the present invention is applied, and FIG. 6 is a view of the main parts of the apparatus used in the method of the present invention shown in FIG. FIG. 7 is a side sectional view, and FIG. 7 is a front view taken along arrows W-VJI in FIG. The compressed gas fluid 14 is directed toward the lead-plated surface 10 (from means 13) of the zinc grains on the galvanized surface 10 side of the strip vertically withdrawn from the galvanizing bath 12. The excess zinc 15 that exceeds the predetermined basis weight is blown off! J11 ft! ('I' ft!) is controlled.

Inhibitor application ut, ゛1. The fused zinc 17 adhering to the surface of tt is blown off by the flame and high temperature gas fluid 18 ejected from the zinc removing means 16. A pot 40-19 is disposed above the zinc coating amount control means 13, and a support roll L! Inhibitor coating 17ii on the steel plate facing IK is performed by non-contact type t1. The steel plate is held by injecting the gas fluid 22 from the support means 21 and pushing it against the support roll 19, which is a lead-plated surface of the copper plate. The pressure of the gas fluid 22 ejected from the non-contact type 1 [.1.1 plate support means 2] is such that the static pressure corresponding to f'1 P shown in FIG. 7 is 100 to 5 (10 mm) in water column.

The horizontal deflection of the steel plate is reduced by the pressing force caused by the static pressure, and as a result, the amount of zinc [] 'l'J by the control means 13 becomes stable, and the steel plate Since directional curvature is also suppressed, a uniform zinc grain size fd of the steel plate can be achieved.

Next, the present invention will be explained by comparing a practical example with a comparative example.

Traveling method V When traveling, target zinc side kH'r, 'i
r: 45 yen/m2, and in the method of the present invention, the above target '
J", (OF/m". S) Length direction of IJ knob and strip l]13QQmm I+] direction I moon view fl/ln2 and several places where Denver color occurs/m2
I looked into this and it is not shown in the table.

(11 When using the device shown in Fig. 2 in which the strip is held between two supporting rolls using the conventional method, the variation in the width is ±(
5-4,) is stable at f/m2, but the Denver color is as high as 30-50 Tsutsukawa/m2. When, [ ] 111 fluctuation is 1 (10 to 15) ft
/m2, which is bad, but the temper color is 0~
(3) When using the apparatus shown in Fig. 5 in which the strip is held by the non-contact type steel plate supporting means and one support roll according to the method of the present invention, the target area h is extremely small.
1. Despite the strict conditions for control, with a target of 3 J/-/m2, the results were extremely good, with a target weight variation of ±3 g/- and a temper color of 0 to 1 location/m2. The measured values in the direction [I+] are shown in Figure 8 (a), (b), (
Shown in e).

The main dimensions of the non-contact type steel plate support means used in this embodiment are as shown in FIG. 6 and the following.

Nozzle gap L'l, 0tan Nozzle angle θ035° Nozzle spacing 1200 questions nozzle: Strip spacing h 200m gas (air)
Discharge speed: 39m/8 Static pressure (water column): 2+)O As stated above, when manufacturing single-sided hot-dip galvanized steel sheets, the method of the present invention is used to process strips pulled from the plating bath in a non-contact manner. The pressing force caused by the jetting of gas fluid from the steel plate supporting means and the back side of the steel plate being pressed against the support roll due to this pressing force presses the steel plate, causing f(-1 horizontal deflection of the plate and the copper plate It is possible to suppress the curvature in the r1 direction, to make the subchain CI'!11 uniform, and to suppress the appearance of temper color.In particular, the method of the present invention makes it possible to make a single-sided hot-dip galvanized outer sheet with a light weight +lφ! It is effective to

[Brief explanation of drawings]

Figure 1 is a process diagram showing an overview of the conventional manufacturing method for single-sided galvanized steel sheets, Figure 2 is a side view of the top of a conventional galvanized bathtub, and Figure 3 is a side view of another conventional galvanized bathtub. 4 is a cross-sectional plan view taken along the line N--N in FIG. 3, and FIG. 5 is a side view of the strip in the p state when the strip is pulled up from the plating bath to which the method of the present invention is applied. , Figure 6 is the fifth
Figure 7 is a side view of the main parts of the apparatus used in the method of the present invention, Figure 7 is a front view as seen from the 1. Strip steel plate, 2. Payoff reel, 3.
...Pre-treatment equipment, 4...Roll coater-15...
Annealing furnace, 6...melting 1J! Lead-plated bathtub, 7... Alloying furnace, 8... Cooling equipment, 9... Inhibitor splinter removal i
UJ: (iii, 10... galvanized, 11...
・Inhibitor 61 cloth, 12...llj lead plating bath, 13
...Subchain ('clear control means, 14...gas fluid, 1
5... How many pieces of lead, 16... Zinc removal means, 17
...Fused zinc 1.18...Flame and high humidity gas fluid,
19... Plated M1i lead side support roll, 2o... Inhibitor coated side support roll, 21... Non-contact type steel plate support means, 22... Gas fluid. Patent Applicant Kawasaki Steel Co., Ltd. Agent Patent Attorney Mura 1) Politics Figure 65 Figure 7 Figure 8 Strip in 97 (b) Strip in Strifer

Claims (1)

[Claims] 1. When manufacturing a single-sided hot-dip galvanized steel sheet, immediately after the steel sheet coated with an inhibitor on one side is immersed in a hot-dip galvanizing bath and the other side is galvanized, the steel sheet is withdrawn.
In the method for controlling the zinc coating amount of a single-sided hot-dip galvanized steel sheet, the zinc coating amount is controlled by spraying a gas fluid onto the galvanized surface. After spraying the fluid, the gas fluid is sprayed onto the surface coated with the inhibitor, and the pressing force caused by the spraying is supported by a support roll provided on the back side of the surface onto which the gas fluid is sprayed. A method for controlling the amount of zinc coating on a single-sided hot-dip 1J tit plated steel sheet, which makes the amount of zinc coating on the galvanized surface of the steel sheet constant.