JPH07303992A - Production of granular body filled tube - Google Patents

Abstract

PURPOSE:To improve productivity and product yield by measuring annealing temp. of a granular body filled tube in running production line and adjusting a supplying quantity of granular body based on the measured annealing temp. CONSTITUTION:The metal strip supplied from a metal strip supply device 11 is formed to a flux filled tube P by a forming device 13, its edge part is welded/ joined by a high frequency induction welding equipment 17. The flux filled tube P is primarily contracted by a primary rolling mill 19, successively, annealed by an annealing device 21, after slowly cooled, it is cooled to normal temp. by water cooling. A radiation thermometer measures a temp. of the annealed flux filled tube, the measured temp. is outputted to a flux supplying quantity controller 15. The flux supplying quantity controller 15 transmits operating signal to a flux supplying device 14, controlling a flux supplying quantity. The annealed flux filled tube P is reduced by a secondary rolling mill 38 to be coiled to a coiler 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a powder / granule-filled tube in which carbon steel, stainless steel, copper alloy, aluminum alloy or other metal tube is filled with the powder / granular material.

Here, the powder or granules mean powder or granules such as welding flux, oxide superconducting material, and additive for molten steel.

[0003]

2. Description of the Related Art There is a flux-cored seamless wire for welding as one of the powder and granular material filling pipes, and the flux-cored seamless wire for welding will be described below as an example.

A flux-cored seamless wire (hereinafter,
In the production of a flux-cored wire), a steel strip is slit by a required width, and the steel strip after slitting is gradually formed from a U-shape to an O-shape by a forming roll. During this forming, the flux is supplied from the opening along the longitudinal direction of the U-shaped strip steel to the strip steel valley portion by the feeder. Then, while forming into an O-shape, the opposite edge surfaces of the opening are joined by welding, and the diameter is subsequently reduced. Further, after annealing if necessary, the tube filled with the flux is drawn into a desired diameter and wound up to obtain a product. As the above-mentioned welding method, high-frequency induction welding, high-frequency resistance welding, and other high-frequency welding are widely used. In all of these welding methods, when formed into a substantially O-shape, the edge surface of the opening is heated to the melting temperature by Joule heat generated by a high frequency current, and the opposing edge surfaces are pressed against each other by a pair of squeeze rolls. As a method for manufacturing such a flux-cored wire, for example, Japanese Patent Laid-Open No. 234795/1985 or Japanese Patent Publication No.
There is a method of manufacturing a flux-cored wire disclosed in Japanese Patent Laid-Open No. -60758.

During the above manufacturing process, the flux is supplied to the tubular body in a preset reference amount. If the amount of flux is more than the standard amount, cracks may occur in the weld when the diameter is reduced. Also, if too little, arc stability,
The function as a flux-cored welding wire for slag generation, deoxidation, etc. is not fully exerted. Therefore, it is necessary to supply the flux at a highly accurate filling rate, for example, 12 ± 1.0%.

The flux filling rate R is expressed by the following equation (1).
Given in. R (%) = flux weight / (outer skin weight + flux weight) × 100 (1)

It is necessary to know the flux filling rate for quality control of the product, and conventionally, the flux filling rate was investigated as follows. First, the forming process of the wire manufacturing line is stopped emergency, the samples are cut out, and the total weight of each sample is weighed. Then, the flux in the sample tube is removed and the weight of the empty tube (outer skin weight) is measured. Then, the flux filling rate is obtained by the above equation (1). If the flux filling rate is within the target setting range, the operation of the wire manufacturing line is continued in the next lot under the same flux supply conditions. In addition, if it goes out of the set range, the lot is rejected.

[0008]

As described above, in the past, the manufacturing process was interrupted because the sample was cut out by emergency stopping the molding process in order to check the flux filling rate. Moreover, in order to maintain the required flux fill factor, the flux fill factor often had to be measured. For this reason, the productivity was significantly reduced. Also,
If the flux filling rate was unacceptable, the entire wound one lot was scrap, resulting in a decrease in yield.

The present invention is intended to provide a method of manufacturing a powder / particle filling tube which can improve productivity and product yield.

[0010]

A first method for manufacturing a powder-filled tube according to the present invention is to supply powder particles to a tubular body while forming a metal strip into a tubular body, and In the method of manufacturing a powder-filled tube in which edge surfaces are joined by high-frequency welding, the welded tube filled with the powder is reduced in diameter and annealed, at least the manufacturing process from the molding process to the annealing process is continuous. The annealing temperature of the powder-and-granule-filled pipe running on the production line is measured, and the supply amount of the powder and granules is adjusted based on the measured annealing temperature.

Annealing is performed by a direct current system, an induction heating system, a gas indirect heating system or the like. As an annealing temperature measuring device, a radiation thermometer or the like is suitable because it can be measured in a non-contact manner with a powder-and-granule-filled tube and has high responsiveness.

According to a second method for manufacturing a powder-filled tube of the present invention, the powder is supplied to the tubular body while the metal strip is being formed into the tubular body, and both edge surfaces of the tubular body are subjected to high-frequency welding. In the manufacturing method of the powder-filled tube, which is joined, the welded pipe filled with the powder is reduced in diameter, and annealed. In the manufacturing method of the powder-filled tube, at least the molding process to the annealing process are continuous, and the powder-filled pipe is Is annealed by electric heating, the heating current is measured, and the supply amount of powdery particles is adjusted based on the measured heating current.

In the first and second inventions, the annealing temperature or the heating current may be measured continuously or intermittently. However, it is desirable to measure continuously from the viewpoint of making the filling rate of the granules uniform over the entire length of the product and improving the product quality. The relationship between the annealing temperature or the heating current and the supply amount of the granular material that gives an appropriate filling rate of the granular material is obtained in advance from the actual operation results of the actual machine or the experiment. In order to adjust the supply amount of the granular material, for example, the opening of the cutout of the hopper accommodating the granular material is adjusted, or in the case of the rotary disk system, the rotation speed of the disk is adjusted. The supply of the powder or granular material is adjusted automatically or manually based on the measured value of the annealing temperature or the heating current. Further, when automatically adjusting the supply amount of powder or granules, a controller or a control device equipped with a computer is used.

When the diameter reducing step comprises two steps, a primary diameter reducing step and a secondary diameter reducing step, annealing is performed between the primary diameter reducing step and the secondary diameter reducing step. Then, the powder or granular material supply amount is adjusted based on the annealing temperature or the heating current measured during the annealing. Further, plating or finish wire drawing may be performed subsequent to the diameter reducing step. When there is a secondary diameter reduction step, secondary annealing may be performed subsequent to the secondary diameter reduction step.

[0015]

[Function] When the supply amount of the granular material changes, the filling rate of the granular material changes. Further, in the diameter reduction step, the wall thickness of the tube changes due to wear of the rolling rolls and changes in tension between the rolling stands applied to the powder / grain filling tube. When the pipe wall thickness changes, the outer skin weight changes, and as is clear from the above formula (1), the powder / granule packing rate changes.

In the first aspect of the invention, when the amount of powder or granular material supplied or the wall thickness of the powder or granular material changes, the heat capacity of the powder or granular material filling pipe changes, and the heating temperature of the powder or granular material filling pipe changes. Therefore, it is possible to know the powder / granule filling rate by measuring the temperature of the powder / granule filling tube, and further to adjust the powder / granular material supply rate to adjust the powder / granular filling rate to a required value. it can.

In the second aspect of the invention, when the supply amount of powder or granules or the wall thickness of the powder changes, the electrical resistance of the powder-filled tube changes and the heating current also changes. Therefore, it is possible to know the filling rate of the granular material by measuring the heating current.
Similar to the invention described in (1), the packing rate of the powder and granules can be adjusted to a required value.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of equipment for carrying out the method of the first invention, showing equipment for manufacturing flux-cored seamless wire for welding.

The flux-cored wire manufacturing equipment mainly comprises a strip feeding device 11, a forming device 13, a flux feeding device 14, a high frequency induction welding device 17, a primary rolling mill 19,
It comprises an annealing device 21, a secondary rolling mill 38, and a winding device 40.

The forming device 13 includes a preforming roll, a forming roll group, a side roll group, which are arranged along the manufacturing line.
A fin pass roll group and a seam guide roll (neither shown) are provided. Further, the flux supply device 14 is arranged in the middle of the side roll group. The flux supply device 14 supplies flux from the opening into the tubular body that is being molded. The flux supply amount is adjusted by the flux supply amount control device 15. A high frequency induction welding device 17 is arranged following the flux supply device 14. The high frequency induction welding device 17 high frequency induction heats the edge portion of the tubular body filled with the flux and presses it down with a squeeze roll (not shown) to join the edge portions. The welding heat input is adjusted by a welding control device (not shown).

The primary rolling mill 19 is a three-roll rolling mill. The primary rolling mill 19 reduces the primary diameter of the flux-filled welded pipe (hereinafter referred to as the flux-filled pipe P).

The annealing device 21 is a direct connection type and a direct current type,
The ring transformer 22 supplies a heating current to the flux filling pipe P between the entrance-side electrode wheel 23 and the exit-side electrode wheel 24. As shown in FIG. 3, the output of the ring transformer 22 is controlled by the temperature control device 25. Temperature control device 25
Includes a voltage / current adjusting device 26. In the voltage / current adjusting device 26, a target current is set by a current setting device 27 and a target voltage is set by a voltage setting device 28.
The voltage / current adjusting device 28 maintains the applied voltage of the ring transformer 22 at the above target voltage, and uses the pulse signal to reduce the S voltage.
CR29 is turned on / off to control the heating current. The heating current is measured by the ammeter 31 and the applied voltage is measured by the voltmeter 32, and the heating current and the applied voltage are feedback-controlled.

A radiation thermometer 3 is provided near the exit side of the annealing device 21.
4 are arranged. The radiation thermometer 34 measures the temperature of the annealed flux filling pipe P.

The winder 40 winds up the flux-filled pipe P having a reduced diameter.

A method of manufacturing the flux-cored wire with the equipment constructed as described above will be described.

A metal strip (SPCC or SPHC, 60 to 65 ^w × 2.0) supplied from the metal strip supply device 11.
.About.2.4 ^t mm) is a molding device 13 having a diameter of 22 mm as an example.
It is formed into a flux filling pipe P of mm, and the high frequency induction welding device 17 welds and joins the edge portion. The flux-filled tube P is first reduced in diameter by the primary rolling mill 19 to a diameter of 11 mm. The tube speed at the exit side of the primary rolling mill 19 is 60 m / min. Next, the flux filling pipe P is annealed in the annealing device 21 at a temperature of 700 to 740 ° C., gradually cooled, and then cooled to normal temperature by water cooling.

The measured temperature of the flux filling pipe P is output to the flux supply amount control device 15. The flux supply amount control device 15 outputs an operation signal (opening / closing signal of the cutout of the flux hopper) to the flux supply device 14,
The flux supply rate is controlled so that the standard flux filling rate is achieved.

The annealed flux-filled pipe P is reduced in diameter to 3 to 4 mm by the secondary rolling mill 38 and wound up by the winding machine 40. Since the manufacturing process from the forming process to the winding process is continuous, the sequence from the metal strip S to the wound flux-filled pipe P is continuous.

A sample was cut out from the flux-cored wire manufactured by the above equipment, and the flux packing ratio was measured. As a result, the flux packing ratio was 12 ± 0.5%. In addition, a flux-cored wire was manufactured by setting the flux filling rate to 12% at the start of manufacturing and maintaining the set flux supply amount constant. As a result, the flux filling rate was 12 ± 0.4%.

FIG. 2 shows an example of equipment for carrying out the method of the second invention, and shows equipment for producing flux-cored welding seamless wire. The same devices as those shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In the first invention, the temperature of the flux filling pipe P is measured by the annealing device 21, and the flux supply amount is adjusted based on the result. On the other hand, in the second invention, the heating current is measured in the annealing apparatus P to adjust the flux supply amount.

The heating current measured by the heating ammeter 36 shown in FIG. 3 is output to the flux supply amount control device 15.
The flux supply amount control device 15 outputs an operation signal to the flux supply device and controls the flux supply amount so that the reference flack filling rate is achieved. The measured flux filling rate of the flux-cored wire manufactured by the above equipment is 12 ± 0.
It was 5%.

[0033]

According to the present invention, it becomes possible to continuously measure the powdery or granular material filling rate in the manufacturing process of the powdery or granular material filling pipe, and it is possible to detect the powdery or granular material filling rate almost in real time. As a result, a. Since it is not necessary to stop the operation of the manufacturing equipment for collecting the sample for measuring the packing ratio of the granular material, the productivity is improved.
For example, as compared with the conventional method, the productivity is increased by 30 to 40%, and the number of workers can be reduced from 6 to 4. b. Since the variation in the filling rate of the powder or granules can be maintained within the allowable range, the yield is improved. For example, compared to the conventional method, 15
~ 20% improved. c. Due to the improvement in productivity and yield, for example, the manufacturing cost is reduced by 20% as compared with the conventional method.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a manufacturing facility for carrying out a method for manufacturing a powder-and-granule-filled tube according to the first invention.

FIG. 2 is a configuration diagram showing an example of a manufacturing facility for carrying out the method of manufacturing a powder / particle filling tube according to the second invention.

FIG. 3 is a configuration diagram of a temperature control device of an annealing device provided in the equipment.

[Explanation of symbols]

 12 strip plate supply device 13 forming device 14 flux supply device 15 flux supply amount control device 17 high frequency induction welding device 19 primary rolling mill 21 annealing device 22 ring transformer 25 temperature control device 34 radiation thermometer 36 heating ammeter 38 secondary rolling Machine 40 Winder S Metal strip P P Flux filling tube

Claims (2)

[Claims] 1. A powdery or granular material is supplied to the tubular body in the course of forming a metal strip into a tubular body, both edge surfaces of the tubular body are joined by high frequency welding, and a welded tube filled with the granular material is compressed. Diameter, in the manufacturing method of the granular material filling pipe to be annealed, at least the manufacturing process from the molding process to the annealing process is continuous, measuring the annealing temperature of the granular material filling pipe running the manufacturing line,
A method for manufacturing a powder-particles-filled tube, which comprises adjusting the powder-particles supply amount based on the measured annealing temperature. 2. A powdery or granular material is supplied to the tubular body during the forming of the metal strip into a tubular body, both edge surfaces of the tubular body are joined by high frequency welding, and a welded tube filled with the granular material is compressed. Diameter, in the manufacturing method of the powder-filled tube to be annealed, at least the manufacturing process from the molding step to the annealing step is continuous, the powder-filled tube is annealed by electric heating, the heating current is measured, and measured. A method for manufacturing a powder-particles-filled tube, characterized in that the supply amount of powders is adjusted based on the heating current.