JP2012087346A - Reflow apparatus of tin-electroplated steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate unnecessary energizing heating to thereby save energy and improve uniformity of product quality of a tin-electroplated steel sheet in the reflow treatment by energizing heating of the tin-electroplated steel sheet.SOLUTION: In a reflow apparatus 6 of the tin-electroplated steel sheet, a tin-electroplated steel sheet S which is tin-electroplated in a plating apparatus and then continuously conveyed is subjected to energizing heating at least with an entrance-side conductor roll 11 and an exit-side conductor roll 12 to allow tin on the surface of the tin-electroplated steel sheet S to melt and then water-cooled by passing through a quench tank 13 containing cooling water. The exit-side conductor roll 12 is arranged in water contained in the quench tank 13, and support rolls 14 are arranged in a plurality of places starting from the position where the tin-electroplated steel sheet S begins to contact the exit-side conductor roll 12 so as to sandwich the tin-electroplated steel sheet S between the support roll 14 and the exit-side conductor roll 12.

Description

  The present invention relates to a reflow apparatus that performs an alloying process (reflow process) on an electrotin-plated steel sheet that is continuously electrotin plated with a plating apparatus in a continuous electrotin plating line.

  In continuous electrotin plating line, reflow treatment is performed to make the plating surface of electrotin plating steel sheet electroplated with plating equipment bright and to form an alloy layer between the metal and tin plating layers. As heating methods for this reflow treatment, there are known methods such as (1) indirect heating by gas and electric heating, (2) resistance heating by direct energization, and (3) induction heating by a high frequency magnetic field. However, the above-mentioned indirect heating method using gas or electric heat has a drawback that it is not responsive and cannot follow changes in operating conditions such as line speed change, and it has the disadvantage that the line length becomes long even in normal cases. Since induction heating by a magnetic field has a disadvantage that the equipment becomes expensive, a heating method by direct energization is widely used.

  In the reflow process using heating by direct energization, an entrance-side conductor roll and an exit-side conductor roll arranged at a predetermined interval are used, and the electrotin-plated steel sheet between these conductor rolls is energized and resistance-heated. Then, the electric tin-plated steel sheet is heated above the melting point (232 ° C.) of tin by this resistance heating to melt the tin on the surface of the electrotin-plated steel sheet, and then rapidly cooled through a quench tank containing cooling water.

  As described above, the reflow apparatus for performing the reflow process by direct energization requires the entry side conductor roll, the exit side conductor roll, and the quench tank, but conventionally, these are in the traveling direction of the electrotin-plated steel sheet. , The entrance conductor roll, the quench tank, and the exit conductor roll were arranged in this order (see Patent Documents 1 to 3).

JP 7-335371 A JP 2000-273682 A JP 2007-169768 A

  In the reflow treatment of the electrotin-plated steel sheet, the temperature of the electrotin-plated steel sheet should originally be equal to or higher than the melting point of tin before entering the quench tank.

  However, according to the positional relationship of the conductor rolls in the conventional reflow apparatus described above, the electrotin-plated steel sheet after exiting the quench tank is also heated by energization. Since the heating of the electrotin-plated steel sheet after leaving the quench tank is unnecessary for the reflow process, energy is wasted correspondingly.

  Therefore, the problem to be solved by the present invention is to save energy by eliminating unnecessary energization heating in the reflow process by electroheating of the electrotin-plated steel sheet.

  In order to solve the above-mentioned problems, the present inventor considered using an underwater roll that has been conventionally arranged as an outgoing conductor roll in order to support an electrotin-plated steel sheet in a quench tank.

  However, it was found that simply using the underwater roll as the outgoing conductor roll has the following problems.

  That is, particularly when the traveling speed of the electrotin-plated steel sheet becomes high, water is caught between the electrotin-plated steel sheet and the outgoing conductor roll due to the viscosity or surface tension of water. If it does so, the electrical resistance between an electrotin plating steel plate and an outgoing side conductor roll will increase, and a power loss will also increase. Further, depending on the traveling speed of the electrotin-plated steel sheet, the electric resistance fluctuates, so that an arc is generated between the electrotin-plated steel sheet and the outgoing conductor roll, and the surface of the electric tin-plated steel sheet and the outgoing conductor roll is increased. There is a risk of wrinkles.

  Therefore, in the present invention, in order to prevent water from being caught between the electric tin-plated steel sheet and the outgoing conductor roll, a support roll is disposed at a position where the electric tin-plated steel sheet begins to contact the outgoing conductor roll. The electrotin-plated steel sheet was sandwiched between the support roll and the outgoing conductor roll.

  That is, the present invention relates to an electrotin-plated steel sheet that has been electrotin-plated continuously by a plating apparatus, and at least the tin on the surface of the electrotin-plated steel sheet is heated by energization heating with an entrance-side conductor roll and an exit-side conductor roll. In the reflow device for electrotinned steel sheet, which is melted and then cooled with water through a quench tank containing cooling water, the outgoing conductor roll is placed in the water of the quench tank, and the electric tinned steel sheet begins to contact the outgoing conductor roll. Support rolls are arranged at a plurality of positions from the position, and the electrotin-plated steel sheet is sandwiched between the support roll and the outgoing conductor roll.

  In the present invention, in addition to the above-described configuration, a weir is disposed on the entry side where the electrotin-plated steel sheet begins to contact the output-side conductor roll, and the cooling water in the quench tank is guided to the electrotin-plated steel sheet. The flow can be prevented from going to a position where the electrotinned steel sheet begins to contact the outgoing conductor roll.

  By providing the weir in this way, it is possible to more reliably prevent water from being caught between the electrotin-plated steel sheet and the outgoing conductor roll.

  In the present invention, since the outgoing conductor roll is arranged in the water of the quench tank, unnecessary energization heating can be eliminated and energy saving can be achieved.

  Furthermore, in the quench tank water, support rolls are placed in multiple locations from the position where the electroplated steel sheet begins to contact the output conductor roll, and the electrotin plated steel sheet is sandwiched between the support roll and the output conductor roll. Therefore, it is possible to prevent water from being caught between the electrotin-plated steel sheet and the outgoing conductor roll, and it is possible to prevent the occurrence of problems such as an increase in electrical resistance and arcing due to the entrainment of water. Further, by providing the weir as described above, it is possible to more reliably prevent the water from being involved.

The structural example of the continuous electrotin plating line to which the reflow apparatus of this invention is applied is shown. 1 shows an embodiment of a reflow apparatus of the present invention. The conventional reflow apparatus is shown. The temperature change and electric power consumption of an electro tin plating steel plate in the reflow apparatus of FIG. 2 are shown. The temperature change and electric power consumption of an electro tin plating steel plate in the reflow apparatus of FIG. 3 are shown. The principal part of the other Example of the reflow apparatus of this invention is shown. The arrangement | positioning of the weir in the reflow apparatus of FIG. 6 is shown. Another embodiment of the reflow apparatus of the present invention will be described.

  Embodiments of the present invention will be described below based on examples shown in the drawings.

  FIG. 1 shows a configuration example of a continuous electrotin plating line to which the reflow apparatus of the present invention is applied.

  In this continuous electric tin plating line, the steel sheet supplied from the payoff reel 1 a or 1 b is introduced into the pretreatment device 4 through the entry side looper 3. In the pretreatment device 4, the steel sheet surface is cleaned by performing pretreatment such as alkali washing, pickling, and water washing of the steel sheet. In addition, the code | symbol 2 in FIG. 1 is a welding machine for connecting a preceding steel plate and a succeeding steel plate and performing a continuous process.

  The steel plate whose surface has been cleaned is subjected to electrotin plating by the plating device 5 and reflowed by the reflow device 6. The electrotin-plated steel sheet subjected to the reflow treatment is introduced into the post-processing device 7. The post-processing device 7 performs post-processing such as discoloration prevention. The electroplated steel sheet after the post-treatment passes through the exit side looper 9 and is taken up by the take-up reel 9a or 9b.

  FIG. 2 shows an embodiment of the reflow apparatus of the present invention applied to the continuous electrotin plating line of FIG. In the reflow apparatus using current heating, the entrance-side conductor roll and the exit-side conductor roll are arranged on the entry side and the exit side in the traveling direction of the electrotin-plated steel sheet. In the reflow apparatus 6 of the present invention, the exit-side conductor roll 12 Is placed in the water of the quench tank 13 containing cooling water, and the electric tin-plated steel sheet S between the inlet-side conductor roll 11 and the outlet-side conductor roll 12 is energized for resistance heating. Then, the electric tin-plated steel sheet S is heated to the melting point (232 ° C.) or higher of tin by this resistance heating to melt the tin on the surface of the electric tin-plated steel sheet S, and then rapidly cooled through the quench tank 13.

  Further, in the reflow device 6 of the present invention, the support rolls 14 are arranged at a plurality of locations (three locations in the embodiment) from the position at which the electrotin-plated steel sheet S starts to contact the outgoing conductor roll 12 in the water of the quench tank 13, The electrotin-plated steel sheet S is sandwiched between the support roll 14 and the outgoing conductor roll 12. Thus, water is prevented from being caught between the electrotin-plated steel sheet S and the outgoing conductor roll 12. In addition, the output side conductor roll 12 can be about 600 mm in diameter, and the support roll 14 can be about 200 mm in diameter.

  On the other hand, in the conventional reflow apparatus, as shown in FIG. 3, the outgoing conductor roll 12 is disposed downstream of the quench tank 13, and an underwater roll 15 is separately disposed in the water of the quench tank 13.

  FIG. 4 shows the temperature change and power consumption of the electrotin-plated steel sheet S in the reflow apparatus 6 of the present invention shown in FIG. Moreover, FIG. 5 shows the temperature change and electric power consumption of the electrotin-plated steel sheet S in the conventional reflow apparatus 6 shown in FIG. 4 and 5, the horizontal axis indicates the position of the reflow device in the traveling direction, and A to E correspond to the positions A to E in FIGS. 2 and 3, respectively. In addition, the position B is a position where the tin on the surface of the electrotin-plated steel sheet S is melted with the electrotin-plated steel sheet S as the melting point of tin (232 ° C.).

  4 and 5, the conventional reflow apparatus heats up to positions A to E, while the reflow apparatus of the present invention heats up to positions A to D. That is, in the past, energization heating was performed even between positions D to E, which are unnecessary for the reflow process, but in the present invention, energization heating is not performed between positions D to E, so that the amount of power used is reduced accordingly. it can. For example, in a general reflow apparatus, the positions A to E are about 20 m and the positions D to E are about 2 m, so that the power consumption can be reduced by about 10% according to the present invention.

  FIG. 6 shows a main part of another embodiment of the reflow apparatus of the present invention. In the reflow device 6 of FIG. 6, the weir 16 is disposed on the entry side (upward in FIG. 6) where the electrotin-plated steel sheet S begins to contact the output conductor roll 12. As shown in FIG. 7, the weir 16 is arranged so as to cover the entire length of the outgoing conductor roll 12. By arranging the weir 16 in this way, the flow of cooling water in the quencher 13 guided to the electrotin-plated steel sheet S is directed to a position where the electrotin-plated steel sheet S starts to contact the outgoing conductor roll 12. Can be disturbed.

  Thus, by providing the weir 16 in addition to the above-described support roll 14, it is possible to reliably prevent water from being caught between the electrotin-plated steel sheet S and the outgoing conductor roll 12.

  In the above embodiment, as an example of the heating method for the reflow process, an example in which electric heating is used alone has been shown. However, as shown in FIG. In addition, electric heating and induction heating may be used in combination.

DESCRIPTION OF SYMBOLS 1a, 1b Payoff reel 2 Welding machine 3 Incoming looper 4 Pre-processing device 5 Plating device 6 Reflow device 7 Post-processing device 8 Outgoing looper 9a, 9b Take-up reel 11 Incoming conductor roll 12 Outgoing conductor roll 13 Quench tank 14 Support roll 15 Underwater roll 16 Weir 17 High frequency induction heating device

Claims (2)

Electrotin-plated steel sheet that has been electrotin-plated continuously by a plating device is cooled after melting tin on the surface of the electro-tin-plated steel sheet by energization heating with at least an entrance-side conductor roll and an exit-side conductor roll. In the reflow device for electrotinned steel sheet, which is water-cooled through a quench tank containing water,
Place the output side conductor roll in the water of the quench tank, place the support rolls at multiple locations from the position where the electroplated steel sheet starts to contact the output side conductor roll, and electroplating with this support roll and the output side conductor roll An electrotin-plated steel sheet reflow apparatus characterized by sandwiching a steel sheet.   A weir is placed on the entry side where the electrotin-plated steel sheet starts to come into contact with the outgoing conductor roll, and the flow of cooling water in the quench tank is guided by the electric tin-plated steel sheet. The reflow apparatus for an electrotin-plated steel sheet according to claim 1, wherein the apparatus is prevented from going to a position at which the contact starts.

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