JP2009091616A - Apparatus for and method of manufacturing hot dip plated steel strip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce production of splash in a gas wiping process by reducing excessive molten metal accompanied with a steel strip to be drawn upwardly from a hot dipping bath over the entire width of the steel strip even when the width of the steel strip is changed. <P>SOLUTION: In an apparatus for manufacturing a hot dip plated steel strip for controlling the hot dip plated deposit on the surface of the steel S strip by spraying gas from a gas wiping nozzle 3 on the surface of the steel strip S to be continuously drawn upwardly from the hot dipping bath 8, molten metal squeezing members 1, 1 of the length equal to or more than the width of the steel strip arranged oppositely to the steel strip S are provided to both sides of the steel strip S under the molten metal surface of a molten metal tank 9, and a shielding body 2 is arranged between the molten metal squeezing members 1, 1 arranged oppositely to the steel strip S on the surface extension of the steel strip. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a molten metal plated steel strip manufacturing apparatus and a method of manufacturing a molten metal plated steel strip that can reduce molten metal splash scattering in a hot dip plating process.

  In a continuous hot dipping process or the like, as shown in FIG. 7, the steel strip S is generally immersed in a hot metal plating bath 8 in the hot metal bath 9 and the direction is changed by the sink roll 7. After the step of pulling the steel strip vertically upward, the steel provided facing the steel strip S so that the molten metal adhering to the steel strip surface has a predetermined plating thickness uniformly in the plate width direction and the plate longitudinal direction. A gas wiping device is provided to control the amount of molten metal deposition (plating deposition amount) by jetting pressurized gas from the gas wiping nozzle 3 extending in the band width direction onto the steel strip to squeeze excess molten metal. It has been.

  In order to stabilize the running position of the steel strip in the gas wiping section, usually, a support roll 5 in the bath is disposed below the bath surface above the sink roll 7, and when alloying is performed, gas is used as necessary. A bath support roll 4 is installed above the wiping nozzle 3.

  The gas wiping nozzle 3 is usually longer than the steel strip width, that is, extends beyond the width end of the steel strip S, in order to cope with various steel strip widths and at the same time to shift in the width direction when the steel strip is pulled up. ing. In such a gas wiping apparatus, a so-called splash is generated in which molten metal falling below the steel strip is scattered by disturbance of the jet that collides with the steel strip S, and the surface quality of the steel strip is degraded.

  Moreover, in order to increase the production amount in the continuous process, the steel plate passing speed may be increased. However, in the case of controlling the coating amount by the gas wiping method in the continuous hot dipping process, due to the viscosity of the molten metal, As the line speed increases, the initial adhesion amount immediately after passing through the plating bath of the steel strip increases, so to control the plating adhesion amount within a certain range, the wiping gas pressure must be set to a higher pressure, As a result, the splash is greatly increased and good surface quality cannot be maintained.

  In order to solve the above problem, Patent Document 1 discloses a method of reducing the initial amount of adhesion immediately after passing through the plating bath by reducing to some extent excess molten metal accompanying the steel plate before reaching the wiping nozzle. Yes.

In Patent Document 1, a molten metal squeeze member is provided between the support roll 5 in the plating solution and the wiping nozzle 3 so as to face both surfaces of the steel strip in a non-contact manner, and after removing excess plating, the plating thickness is increased by gas wiping. In the adjusting device, the shape of the molten metal squeezing member is preferably a rectangular shape or a cylindrical body having an introduction portion whose distance from the front and back surfaces of the steel strip becomes wider at the lower end. The position that straddles the top and bottom of the liquid level is most desirable. Further, it is desirable that the molten metal squeezing member surround the steel strip.
JP 2004-76082 A

  However, in the method disclosed in Patent Document 1, even if the molten metal squeezing member can squeeze excess molten metal at the center portion in the steel strip width direction, the steel strip from the outside is formed at both ends in the steel strip width direction. Since the molten metal flows toward the center in the width direction, the squeezing effect of the molten metal decreases at both ends in the steel strip width direction. For this reason, the difference in the amount of excess molten metal is greater at the center and both ends in the width direction than when the molten metal drawing member is not installed, and the effect of reducing splash is reduced in the subsequent gas wiping step. I understood it. Moreover, in the shape which encloses the steel strip described in patent document 1, since it cannot respond to the width change of the steel strip to manufacture, the board width size which can express the drawing effect of a molten metal is limited.

  In consideration of the above-mentioned problems, the present invention makes it possible to reduce the excess molten metal accompanying the steel sheet pulled up from the plating bath over the entire width of the steel strip even if the steel strip width changes, so that the splash in the gas wiping process is achieved. It is an object of the present invention to provide a molten metal plated steel strip manufacturing facility that can stably produce a molten metal plated steel strip that is excellent in surface appearance.

  Moreover, this invention makes it a subject to provide the manufacturing method of the steel strip which can reduce generation | occurrence | production of the splash in a gas wiping process and can manufacture stably the molten metal plating steel strip excellent in the surface appearance.

  If a molten metal squeezing member for removing excess molten metal is installed between the sink roll and the gas wiping nozzle, the molten metal removed by gas wiping flows down, and the steel strip and the molten metal squeezing member A liquid pool is formed in the gap. If the distance from the liquid reservoir to the gas wiping portion is short, the amount of excess molten metal cannot be reduced, and the present inventors say that it is best to install the molten metal drawing member below the plating solution surface. I came to a conclusion.

  However, even if a molten metal squeezing member is simply installed, the molten metal squeezing effect at both ends of the steel strip is small. Therefore, in order to effectively reduce the amount of molten metal associated with the steel strip coming out of the plating bath, a detailed flow analysis was performed using a water model device that simulates the flow of molten metal around the molten metal throttle member. . As a result, it was found that to reduce the amount of molten metal lifted from the plating bath accompanying the steel strip, it is effective to suppress the flow from both ends of the steel strip toward the center of the steel strip.

  Based on the above findings, the present inventors have completed an invention having the following characteristics.

  (1) A molten metal plating steel strip manufacturing apparatus that controls the amount of plating on the surface of a steel strip by blowing gas from a gas wiping nozzle onto the surface of the steel strip that is continuously pulled up from the molten metal plating bath. On both sides of the steel strip below the liquid level of the metal tank, there is a molten metal drawing member with a length equal to or greater than the width of the steel strip disposed facing the steel strip, and further facing the steel strip on the steel strip surface extension. An apparatus for producing a molten metal-plated steel strip, wherein a shield is disposed between the molten metal drawn members arranged in the manner described above.

  (2) The length of the steel strip facing surface of the shield is 50% or more of the length of the steel strip facing surface of the molten metal drawing member (the length of the steel strip facing surface of the molten metal drawing member). When the steel strip traveling direction length is different on both sides of the steel strip, 50% of the steel strip traveling direction length of the steel strip facing surface of the steel strip facing surface of the molten metal drawn member is smaller. The apparatus for producing a molten metal-plated steel strip according to (1), wherein the distance between the molten metal constricting member and the shield is 3 mm or less.

  (3) A method for producing a hot-dip metal-plated steel strip, comprising performing hot-dip metal plating on a steel strip using the apparatus for producing a hot-dip metal-plated steel strip according to (1) or (2).

  According to the present invention, the gas wiping nozzle can be used after reducing the excess molten metal amount accompanying the steel strip over the entire width of the steel strip even if the steel strip width is changed by the molten metal constricting member and the shield provided below the plating bath surface. Since it becomes possible to adjust the plating thickness, the amount of splash can be greatly reduced. In addition, according to the present invention, the amount of splashing can be greatly reduced even when the plate passing speed is significantly increased, so that it is possible to manufacture a molten metal plated steel strip without surface defects while maintaining high productivity. It becomes possible.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same reference numerals are given to parts having the same functions as the parts shown in the already described drawings, and the description thereof is omitted.

  FIG. 1 is a cross-sectional view showing an embodiment of the apparatus for producing a molten metal plated steel strip of the present invention. In FIG. 1, reference numeral 1 denotes a molten metal drawing member installed in the plating bath, which is installed at a position a predetermined distance away from the steel strip surface on both sides of the steel strip S above the support roll 5 in the bath. Yes. A shield 2 is disposed between the molten metal squeezing members 1 and 1 disposed to face the steel strip S on the steel strip surface extension, in proximity to the end of the steel strip S.

  FIG. 2 is a view for explaining the operation of the molten metal squeezing member and the shield of the apparatus of the present invention. FIG. 2 (a) shows the end of the steel strip in the region sandwiched between the molten metal squeezing members when the molten metal squeezing member is provided The top view which shows the flow of the molten metal in a part, (b) is a top view which shows the flow of the molten metal in the steel strip edge part in the area | region pinched | interposed by the molten metal restricting member in the case of providing a molten metal restricting member and a shield. is there. Regardless of the shape of the molten metal squeezing member 1, if only the molten metal squeezing member 1 is arranged, a molten metal flow 11 from the end of the steel strip toward the center of the steel strip is generated as shown in FIG. . As the plating squeezing effect by the molten metal squeezing member 1 increases, the molten metal flow 11 tends to increase so as to compensate for it. Therefore, the drawing effect of the molten metal drawing member 1 is weakened or disappears at both ends of the steel strip. As shown in FIG. 2 (b), when the shield 2 is disposed between the molten metal drawn members 1 and 1 disposed opposite to the steel strip on the steel strip surface extension, the steel strip center from the end of the steel strip. Since the flow of the molten metal toward the part can be cut off, the excessive molten metal squeezing effect by the molten metal squeezing member 1 can be expressed uniformly over the entire width of the steel strip.

  Even if the steel strip width changes due to the molten metal drawing member and shield, the plating thickness can be adjusted with the gas wiping nozzle after reducing the excess molten metal amount accompanying the steel strip over the entire width of the steel strip, greatly increasing the amount of splash generated. Can be reduced. According to the present invention, since the molten metal squeezing effect can be exhibited even when the plate passing speed is significantly increased, the amount of splash generated can be greatly reduced, so that the molten metal plated steel strip having no surface defects is highly productive. It can be maintained and manufactured.

  The steel strip side end surface of the shield 2 is preferably orthogonal to the steel strip surface as shown in FIG. The distance between the end of the steel strip and the end surface of the shield 2 on the side of the steel strip is preferably 5 mm or less, and the smaller the distance, the better. Furthermore, the most preferable condition is that the end of the steel strip and the end surface of the shield 2 on the side of the steel strip are in contact with each other in a state where no pressing force is applied to the steel strip.

  The gap between the molten metal squeezing member 1 and the shield 2 is desirably 3 mm or less, and the gap is preferably as small as possible.

  From the viewpoint of preventing the flow of molten metal toward the center of the steel strip between the molten metal squeezing members 1, 1, the length of the shield 2 facing the steel strip in the traveling direction (vertical length) is at least a molten metal squeeze. The length of the member 1 is preferably 50% or more of the length in the direction of travel of the steel plate, and most preferably the same length as the molten metal drawing member 1.

  When the distance between the steel strip facing surface of the molten metal squeezing member 1 and the steel strip changes in the steel strip traveling direction, it is preferable to keep the gap between the molten metal squeezing member 1 and the shield 2 in the steel strip traveling direction as constant as possible. . For example, when the cross-sectional shape of the molten metal squeezing member 1 is circular as shown in FIG. 3, the surface of the shield 2 facing the molten metal squeezing member 1 has a curvature slightly larger than the radius of curvature of the arc of the molten metal squeezing member 1. It is preferable to form a concave arc surface having a radius.

  The cross-sectional shape of the molten metal squeezing member is not limited to the shape shown in FIG. Various shapes can be employed as described below. For example, as shown in FIG. 4 (a), when the cross-sectional shape is a triangle and the surface facing the steel strip S and the top surface facing the bath surface are parallel to the steel strip S and the bath surface, respectively, The aperture performance of the member 1 can be further improved. If the cross-sectional shape of the molten metal squeezing member 1 is such a shape, even if a flow (associated flow) 11 accompanying the progress of the steel strip S is generated, the fluid tends to flow in the direction of low resistance. The flow 13 branches off at the lower end of the throttle member 1 and functions to prevent the growth of the accompanying flow 11. Furthermore, since the flow 13 is directed away from the steel strip S, the flow 13 is opposed to the flow 12 toward the steel strip S above the molten metal squeezing member 1, and has the effect of reducing the speed of the flow 12. Since the molten metal squeezing member 1 performs the flow control as described above, it is possible to significantly suppress the accompanying flow in the vicinity of the steel strip S lifted from the plating bath, and excessive molten metal plating associated with the steel strip S is prevented. The amount can be reduced. As a result, the wiping gas pressure can be reduced, the amount of molten metal splash generated can be reduced, and a plated steel strip with good surface quality can be produced. In this case, the cross-sectional shape of the shield 2 may be a rectangle as shown in FIG.

  The cross-sectional shape of the molten metal squeezing member 1 in FIG. 5 (a) is such that the cross-sectional curve on the upper surface and the cross-sectional curve on the lower surface are both in a convex arc shape on the steel strip lifting portion side of the molten metal plating bath, and Is formed to be smaller than the curvature radius of the arc of the lower surface. Moreover, the thickness of the molten metal squeezing member 1 decreases toward the end portion on the anti-steel strip side and the end portion on the anti-bath surface. The shape of the molten metal squeezing member 1 is the shape that most significantly shows the effect of branching the accompanying flow 11 into the flow 13 and the effect of forming a counterflow to the flow 12.

  In this case, the surface of the shield 2 facing the molten metal squeezing member 1 has a curvature slightly larger than the radius of curvature of the arc of the surface of the molten metal squeezing member 1 facing the shield 2 as shown in FIG. It is preferable to use a concave arcuate surface having a radius so that the distance between the molten metal squeezing member 1 and the shield 2 is kept as constant as possible.

  The molten metal squeezing members 1a and 1b shown in FIG. 6 (a) are disposed so as to cover the bath surface side of the outer peripheral surface of the in-bath support roll 5, and are disposed above and opposed to the steel strip. And a steel strip facing portion formed as described above. The support rolls 5 in the bath are arranged on both sides of the steel strip so as to be in contact with the steel strip so that their vertical positions are different from each other. Therefore, the lengths of the steel strip facing portions of the molten metal squeezing members 1a and 1b arranged on both sides of the steel strip S are different from each other. The steel strip facing portions of the molten metal squeezing members 1a and 1b may be parallel to the steel strip surface or may be inclined.

  In the molten metal squeezing members 1a and 1b, a flow 11 associated with the in-bath support roll 5 is generated between the in-bath support roll 5 and the molten metal squeezing members 1a and 1b. When the flow 11 is generated, even if the accompanying flow 12 accompanying the progress of the steel strip S is generated, the forced force in the direction opposite to the travel direction of the steel strip S is forced between the steel strip S and the molten metal throttle members 1a and 1b. A flow 13 is generated and the accompanying flow 12 is greatly suppressed. Thereby, the excess molten metal amount accompanying the steel strip S pulled up from a plating bath can be reduced.

  The molten metal squeezing member may be provided with only the steel strip facing portions of the molten metal squeezing members 1a and 1b shown in FIG. In this case, the length of the steel strip facing portions of the molten metal squeezing members 1a and 1b arranged on both sides of the steel strip may be the same in the length of the steel strip.

  In the case where the molten metal squeezing member is shown in FIG. 6A and the above case, the cross-sectional shape of the shield 2 may be a rectangle as shown in FIG. 6B. In this case, the length of the steel strip facing surface of the shield is 50% or more of the length of the steel strip facing surface of the molten metal drawing member (the length of the steel strip facing surface of the molten metal drawing member). When the steel strip traveling direction length is different on both sides of the steel strip, 50% of the steel strip traveling direction length of the steel strip facing surface of the steel strip facing surface of the molten metal drawn member is smaller. It is preferable that the length of the molten metal squeezing member is equal to the length of the steel strip facing direction of the steel strip (the length of the molten metal squeezing member facing the steel strip is equal to the length of the steel strip in both directions of the steel strip). When they are different, it is more preferable that the length is the same as the length of the steel strip facing surface of the smaller steel strip.

  The dimensions and shape of the molten metal squeezing member need to be determined as appropriate in consideration of the equipment to be applied and the sheet feeding speed of the steel strip.

  The height of the shield 2 in the traveling direction of the steel strip should be the same as that of the molten metal plating throttle member 1, and the vertical positions of the upper end and the lower end of the molten metal throttle member 1 and the shield 2 coincide with each other at the time of installation. It is preferable to make it. When the length of the shield 2 in the steel plate traveling direction is shorter than the length of the molten metal squeezing member 1 in the steel plate traveling direction, the shield 2 is installed on the side closer to the bath surface, that is, the upper end of the shield 2 is the upper end of the molten metal squeezing member 1. It is desirable that the position be substantially the same. The length of the shield 2 in the steel strip width direction is preferably 100 mm or more. Although an upper limit is not limited, since an installation will become excessive if this length becomes large, about 500 mm or less is preferable.

  The hot-dip galvanized steel strip production apparatus shown in FIG. 1 was installed in the continuous hot-dip galvanizing line, and a hot-dip galvanized steel strip production experiment was conducted. The vertical offset between the support rolls in the bath arranged on both sides of the steel strip S is 200 mm, and the distance between the bath surface and the upper end of the support roll in the bath on the side close to the bath surface is 80 mm. The diameter of the support roll in the bath is φ400 mm.

  The length of the molten metal drawing member 1 in the width direction of the steel strip is 2000 mm corresponding to a gas wiping nozzle, the distance between the upper end of the molten metal drawing member and the bath surface is 5 mm, and the distance from the steel strip is 3 mm (Comparative Example 5 and Example) 4) and fixedly arranged on both sides of the steel strip to face the steel strip surface. The shield 2 has a length in the width direction of the steel strip of 200 mm, and is directly connected to a position where the frame is extended from a position control device by a servo motor provided on the machine side, and is movable according to the width of the steel strip.

The galvanized steel strip production conditions are as follows: the slit gap of the gas wiping nozzle is 0.8 mm, the distance between the gas wiping nozzle and the steel strip is 7 mm, the nozzle height from the molten zinc bath is 400 mm, and the molten zinc bath temperature is 460 ° C. The size was 0.8 mm thickness × 1.2 m width, and the amount of plating was 45 g / m ^{2 on} one side. The distance between the shield 2 and the end of the steel strip was controlled to approximately 3 mm.

  Table 1 shows the results of the investigation of the amount of splash generation, which is another production condition and product quality index. Specific dimensions and shapes of the molten metal restricting member and the shield used in each comparative example and each example will be described below. The splash generation amount is a ratio of the steel strip length determined to have a splash defect in the inspection process to the steel strip length passed under each manufacturing condition, and includes a slight splash defect that does not cause a problem in practice.

  Comparative Example 1 (conventional example) is a case where there is neither a molten metal throttle member nor a shield. Splash incidence was 1.40%.

  Comparative Example 2 uses only a molten metal drawn member having a square cross section with a steel strip traveling direction length and a horizontal length of 50 mm each, and Example 1 is further compared with Comparative Example 2 in the steel strip traveling direction. A rectangular shield plate having a length of 50 mm and a horizontal length of 4 mm was additionally installed (the distance between the molten metal throttle member and the shield plate is 1 mm). In Comparative Example 2, the incidence of splash was reduced by approximately 25% compared to Comparative Example 1. In Example 1, the splash rate was almost halved compared to Comparative Example 1, and the splash rate was reduced by about 31% compared to Comparative Example 2.

  In Comparative Example 3, only the molten metal drawing member having a steel strip traveling direction length and a horizontal direction length of 50 mm and a triangular cross-sectional shape was arranged as shown in FIG. In Example 2, a shield with a rectangular cross section having the same size and shape as Example 1 was additionally installed as compared to Comparative Example 3 as shown in FIG. 4B (the distance between the molten metal squeezing member and the shielding plate is 1 mm). In Comparative Example 3, the splash occurrence rate was reduced by about 70% compared to Comparative Example 1. In Example 2, the splash rate was reduced by 80% compared to Comparative Example 1, and the splash rate was reduced by approximately 32% compared to Comparative Example 3.

  In Comparative Example 4, only the molten metal squeezing member having a steel strip traveling direction length and a horizontal direction length of 50 mm and an arc-shaped cross section (upper surface radius of curvature 60 mmR, lower surface radius of curvature 100 mmR) is shown in FIG. ). The distance between the lower end of the molten metal squeezing member and the steel strip was 3 mm.

  In Example 3, compared to Comparative Example 4, the cross-sectional shape shown in FIG. 5B, that is, the length in the steel plate traveling direction is 50 mm, and the surface of the shield facing the molten metal squeezing member is FIG. 2 shows a shield made of a concave arc surface having a radius of curvature slightly larger than the radius of curvature of the arc of the surface facing the member shield, and created so that the distance from the molten metal drawing member is 1 mm. Additional installation was performed as shown in FIG.

  In Comparative Example 4, the splash occurrence rate was reduced by about 84% compared to Comparative Example 1. In Example 3, the splash rate was reduced by about 90% compared to Comparative Example 1, and the splash rate was reduced by about 30% compared to Comparative Example 4.

  Comparative Example 5 is an arc-shaped roll covering portion that covers the bath surface side of the outer peripheral surface of the in-bath support roll 5 formed such that the distance between the support roll 5 in the bath and the molten metal squeezing members 1a and 1b is 30 mm; The molten metal squeezing member 1a is provided with a plate-shaped steel strip facing portion formed so that the distance between the steel strip and the molten metal squeezing members 1a and 1b is constant 20 mm and the distance between the upper end and the bath surface is 30 mm. Only 1b was arranged as shown in FIG.

  In Example 4, as compared with Comparative Example 5, a shield having a steel strip traveling direction length of 100 mm and a horizontal length of 36 mm was additionally installed as shown in FIG. The distance between the shield and the molten metal restricting member is 2 mm. The ratio of the steel strip traveling direction length of the shield to the steel strip traveling direction length of the steel strip facing portion of the molten metal drawing member 1b is approximately 90%.

  In Comparative Example 5, the incidence of splash was reduced by approximately 85% compared to Comparative Example 1. In Example 4, the splash occurrence rate was reduced by about 94% compared to Comparative Example 1, and the splash occurrence rate was reduced by about 33% compared to Comparative Example 5.

  The apparatus of the present invention can be used as a manufacturing apparatus for a hot-dip plated steel strip that reduces the occurrence of splash and has an excellent surface appearance. Since the apparatus of the present invention can suppress the occurrence of splash even at the time of high-speed plate feeding, it can be used as an apparatus for manufacturing a molten metal plated steel strip excellent in surface appearance while maintaining high productivity.

  Moreover, the manufacturing method of the steel strip of this invention can be utilized as a manufacturing method of the hot-dip metal plating steel strip which reduces generation | occurrence | production of a splash and is excellent in surface appearance.

It is sectional drawing which shows one Embodiment of the hot-dip metal plating steel strip manufacturing apparatus of this invention. It is a figure explaining the effect | action of the molten metal restricting member and shield of the molten metal plating steel strip manufacturing apparatus of this invention. It is a 1st figure explaining the example of a combination of the cross-sectional shape of the molten metal restricting member used for the molten metal plating steel strip manufacturing apparatus of this invention, and a shield. It is the 2nd figure explaining the example of a combination of the cross-sectional shape of the molten metal narrowing member installed in the molten metal plating steel strip manufacturing apparatus of this invention, and the cross-sectional shape of a shield. It is a 3rd figure explaining the example of a combination of the cross-sectional shape of the molten metal narrowing member installed in the molten metal plating steel strip manufacturing apparatus of this invention, and the cross-sectional shape of a shield. It is a 4th figure explaining the example of a combination of the cross-sectional shape of the molten metal narrowing member installed in the molten metal plating steel strip manufacturing apparatus of this invention, and the cross-sectional shape of a shield. It is sectional drawing which shows a general molten metal plating steel strip manufacturing apparatus.

Explanation of symbols

S Steel strip 1, 1a, 1b Molten metal throttle member 2 Shield 3 Gas wiping nozzle 4 Support roll on bath 5 Support roll in bath 7 Sink roll 8 Molten metal plating bath 9 Molten metal bath

Claims (3)

A molten metal-plated steel strip manufacturing apparatus that controls the amount of plating on the surface of a steel strip by blowing gas from a gas wiping nozzle onto the surface of the steel strip that is continuously pulled up from the molten metal plating bath. On both sides of the steel strip below the liquid level, there is a molten metal drawing member having a length equal to or greater than the steel strip width disposed opposite to the steel strip, and further disposed opposite the steel strip on the steel strip surface extension. An apparatus for manufacturing a molten metal-plated steel strip, comprising a shield disposed between molten metal squeezing members. The steel strip traveling direction length of the steel strip facing surface of the shield is 50% or more of the steel strip traveling direction length of the steel strip facing surface of the molten metal drawing member (the steel strip traveling direction of the steel strip facing surface of the molten metal drawing member) When the direction length is different on both sides of the steel strip, it is more than 50% of the length of the steel strip facing surface of the steel strip facing surface of the molten metal drawing member with the smaller length of the steel strip facing surface) The apparatus for producing a molten metal plated steel strip according to claim 1, wherein the distance between the molten metal squeezing member and the shield is 3 mm or less. A method for producing a molten metal-plated steel strip, comprising performing the molten metal plating on the steel strip using the apparatus for producing a molten metal-plated steel strip according to claim 1 or 2.

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