JP4075767B2 - Steel pipe manufacturing history management method - Google Patents

Description

  The present invention relates to a manufacturing history management method for steel pipes. In particular, when a secondary machined part is manufactured using ERW steel pipe or the like as a material, and trouble occurs in the secondary machined part later, the material history can be pursued. It is related to technology.

  In general, an electric resistance steel pipe is formed by forming a cylindrical shape with a group of forming rolls while rewinding a steel strip wound in a coil shape (hereinafter simply referred to as a coil) with an uncoiler and continuously running the steel strip. It is manufactured by welding both ends in the width direction of the steel strip. That is, for the production, for example, a steel slab obtained by continuously casting molten steel is heated to a predetermined temperature (usually 1200 to 1300 ° C.) in a heating furnace, and then rolled up to a constant width by hot rolling. A coil is used. Then, as shown in FIG. 7, the coil 1 is rewound by the uncoiler 2, smoothed by the leveler 3, and both ends in the width direction are adjusted by the edge mirror 4, and then rolls having various shapes are arranged in multiple stages. The steel strip is leveled and fed at a constant speed to the group of forming rolls 5 provided. The tubular body processed by the forming roll 5 (referred to as an open pipe since the end portions in the width direction that have been butted are not joined) is continuously connected to the induction coil 6 at both ends in the width direction that have been butted. And is pressed with a squeeze roll 7 and is crimped and welded to form a steel pipe 8 (hereinafter referred to as a base pipe 8). Since the protrusions called beads are formed on the inner and outer surfaces of joint portions (hereinafter referred to as seam portions) extending substantially linearly continuously in the longitudinal direction of the base tube 8, the beads are bead cutting means 9. Or is smoothed by a special rolling mill that rolls the outer surface or the inner surface. Further, the raw tube 8 is cut to a certain length by a running cutter 10, dimensioned by a multi-stage drawing mill such as a sizer, and inspected to have a desired size and characteristics, It becomes ERW steel pipe 13 as a product. The coil 1 is divided into slits in the width direction of the steel strip or cut in the longitudinal direction according to the user's demand, that is, the size and amount of the ERW steel pipe to be manufactured. It is often used after being set to 1.

  Such an electric resistance welded steel pipe 13 has a use as a material for manufacturing parts such as suspension pipes and exhaust gas pipes of a “vehicle” such as an automobile. These parts are manufactured by further cutting (1-3m) the ERW steel pipe of the fixed length (fixed length: 10m) that has been shipped and then performing secondary processing such as bending and partial enlargement. And finally incorporated into the vehicle.

  By the way, when a vehicle such as an automobile has some trouble after being released, it may be a situation where a car incorporating the same kind of problem part is collected in order to replace the part. is there. This recovery is labor intensive, time consuming and expensive, so it is desirable to incorporate defect-free parts and avoid recovery as much as possible. It is also important to find out the cause of the trouble from the viewpoint of safety and prevention of recurrence. In that case, the defective part is removed from the collected automobile, and the material history of the defective part is asked.

Conventionally, this material history is managed by attaching a tag with the factory, date of manufacture, and order number (the coil number) to a bundle of steel pipes to be shipped (a collection of several dozen steel pipes). Was. Specifically, as shown in FIG. 6, a steel pipe 13 having a predetermined length manufactured in the process shown in FIG. 7 is bundled and shipped from the coil 1 corresponding to the order. Thereafter, the cutting company cuts into the length of the secondary processed part 16 of the automobile 15, stores it in the pallet (150 pallets) 14, and supplies it to the final processing source (automator manufacturing factory or the like). Therefore, there is a problem that the material of the defective part can be identified only by at least one coil 1 (about 10 tons in weight). That is, since the number of secondary processed parts 16 manufactured from one coil is enormous, the number of automobiles that must be collected is also very large.
In addition, the manufacturing history may be printed on the outer surface of each steel pipe 13, but in practice, the steel pipe 13 is used after being coated on the outer surface, so the printing cannot be read. Further, since the outer surface printing has the same contents as the tag, the current situation is that it is not very effective in pursuing the material history of each secondary processed part 16.

  In view of such circumstances, an object of the present invention is to provide a manufacturing history management method of a steel pipe capable of pursuing the material history for each of the secondary processed parts made of the steel pipe as a raw material or for individual steel pipes before shipment. It is said.

  The inventor has intensively studied to achieve the above object, and the results have been embodied in the present invention.

  That is, in the present invention, the coiled steel strip is rewound by an uncoiler and continuously formed while being formed into a cylindrical shape or a spiral shape with a group of forming rolls, and then welded at both ends in the width direction of the abutted steel strips. When the steel pipe is manufactured by cutting to a certain length, secondary processing is performed in which the steel pipe of the certain length is further cut on the surface of the steel strip which is unwound and becomes the inner surface side of the steel pipe after forming. The manufacturing information of the steel strip is printed or stamped for each part length range, and the welding conditions, nondestructive inspection results, annealing conditions corresponding to the printed or stamped positions applied in the subsequent process And a manufacturing history management method for steel pipes, wherein a mark of a defective part is stored in a computer.

  Further, the present invention replaces the printing or stamping of the manufacturing information of the steel strip with the welding conditions, the results of nondestructive inspection, the annealing conditions, and the marks of defective parts on the inner surface or outer surface of the steel pipe having the predetermined length. A manufacturing history management method for steel pipes, characterized in that a separately stored microchip is attached.

  In this case, it is preferable that the steel pipe is an electric-resistance-welded steel pipe, or the secondary processed part is an automobile part. The steel strip manufacturing information referred to in the present invention includes the manufacturing date and time, the skelp number and position (distance from the tip).

  In the present invention, the manufacturing information of the steel strip is printed or stamped on the surface of the steel strip corresponding to the steel pipe that is the material of the final secondary processed part, and the manufacturing information about the subsequent process is stored in the computer at that position. I made it. As a result, even if trouble occurs in the secondary processing parts, the manufacturing information of the steel strip and the manufacturing history of the steel pipe can be retroactively determined in units of the secondary processing parts. In particular, a reduction in the number of recovered cars can be achieved. Moreover, the microchip which memorize | stored the manufacturing information of the said steel pipe was affixed on the inner surface or the outer surface of the said steel pipe. As a result, it is possible to determine whether the steel pipe is good or bad before shipment and to automatically sort good products, thereby preventing troubles.

  Hereinafter, the best embodiment of the present invention will be described based on the background to the invention.

  First, the inventor thought that in order to reduce the number of automobiles and the like collected, it is necessary to be able to retroactively manufacture the material history for each secondary processed part. To that end, we thought that it would be good to make some markings for each steel pipe used as the material, and examined specific means. And since marking on the outer surface side of the steel pipe cannot be deciphered by painting as described above, the idea was to use the inner surface side as shown in FIG. That is, as shown in FIG. 2, the manufacturing information of the steel strip is marked on the surface of the steel strip 17 before being formed into a cylindrical shape or a spiral shape. At that time, the marking position becomes a problem. This is because every time within the range of the length of the secondary processed part 16 produced by further cutting the steel pipe 13 of a certain length obtained in the manufacturing process, that is, the secondary processing. What is necessary is just to perform by the pitch of the range used as the length of the components 16. FIG.

  The inventor also examined the content of the marking, and made it the date of manufacture, the skelp number of the steel strip used, and the skelp position (distance from the tip of the skelp). As the marking means, a printing device and a marking device that can be easily obtained can be used. By performing such printing or engraving, when a trouble occurs in the secondary processed part 16, it can be disassembled and the material history can be identified for each secondary processed part.

  Furthermore, the inventor considers that the manufacturing information of the steel pipe about the various processing performed after that in the printed and engraved position is necessary for pursuing the cause of the trouble, and tracking the information by the length of the skelp 1. And adding it to a computer (not shown). The manufacturing information includes welding conditions, nondestructive inspection (for example, ultrasonic flaw detection) results, annealing conditions, and defective part marks.

  The present invention has been completed with the above-described marking on the inner surface of the steel pipe, marking contents, and computer storage of information.

  Next, the inventor considered that in order to reduce the number of automobiles and the like to be recovered, the quality of the steel pipe 13 that is the material of the secondary processed part 16 is judged as good or bad, and if possible, it is only necessary to be able to automatically sort good products. Then, in determining whether the product is good or bad, the manufacturing information of the steel pipe is used, and the stored contents are transferred from the computer storing them to the microchip 18 by, for example, a bar code or the like, as shown in FIG. Furthermore, it was considered that the microchip 18 was attached to the inner surface or the outer surface of the steel pipe 13. In this way, it is possible to automatically read the manufacturing information from the microchip 18 by the sensor before the coating of the outer surface of the steel pipe 13 and before shipment, and to select the quality. Thereafter, if the quality of the steel pipes 13 is manually or automatically sorted, only steel pipes having a desired quality can be shipped. Therefore, this method is also added to the present invention. Also, if the microchip is attached and sent to the user, the identification can be made there.

  Needless to say, the present invention in which the microchip is attached is applicable not only to the above-described ERW steel pipe but also to spiral steel pipes, seamless steel pipes, and drawn steel pipes.

  The three skelpes 1 wound with a steel strip of carbon steel are made into an electric-welded steel pipe 13 having a size of outer diameter 76.3 mmφ × thickness 3.2 mm × length 10 m in the process shown in FIG. . At that time, the production history management method of the steel strip according to the present invention is applied, and the production information of the steel strip is provided on the surface of the steel strip before forming at the pitch of the length of the secondary processed part to be finally produced. Printed. For example, the content of the print is “03026161525AB-0542”. This means that on May 26, 2003, 15:25, the skelp number (AB), the distance 542m from the skelp tip. Information corresponding to the printing position is tracked by the length of the steel strip and stored in the computer. As shown in FIG. 4, the manufactured steel pipe 13 was shipped as a bundle of 30 bundles. Then, the cutting company cut | disconnected to the length of the final secondary processed goods, stored 100 pieces in each pallet 14, and supplied to the manufacturing factory of the automatic person. These steel pipes 13 were made into secondary processed parts 16 in an automobile factory and incorporated into automobiles.

  At a later date, there was a problem that the secondary processed part 16 incorporated in the automobile 15 had a defect. Therefore, the manufacturing history of the secondary processed part 16 in question was investigated as shown in FIG. As a result, it became clear that the troubled secondary processed parts 16 were limited to those manufactured with the steel pipes 13 housed in a specific pallet 14. It was decided to collect only automobiles incorporating the processed parts 16. That is, 100 secondary processed parts were collected. According to the conventional manufacturing history management method, only the skelp 1 can be traced back, so this greatly reduces the number of recovered vehicles.

It is a figure which shows the concept of this invention. It is a figure explaining the manufacture log | history management method of the steel pipe which concerns on this invention. It is a figure explaining another form of the manufacture log | history management method of the steel pipe which concerns on this invention. It is a figure which shows the flow of the steel pipe at the time of implementing the manufacturing log | history management method of the steel pipe concerning this invention. It is a figure which shows the flow of the manufacture log | history investigation of the steel pipe performed when a defective vehicle generate | occur | produces. It is a figure explaining the manufacture log | history management method of the conventional steel pipe. It is a flowchart explaining the manufacturing process of a general ERW steel pipe.

Explanation of symbols

1 coil (coiled steel strip) or skelp 2 uncoiler 3 leveler 5 forming roll 6 induction coil 7 squeeze roll 8 base steel pipe (base pipe)
9 Bead cutting means 10 Running cutting machine 13 Steel pipe (ERW steel pipe)
14 Pallet 15 Automobile 16 Secondary machined parts 17 Steel strip 18 Microchip

Claims (4)

While the coiled steel strip is rewound with an uncoiler and continuously run, it is formed into a cylindrical or spiral shape with a group of forming rolls, and then welded at both ends in the width direction of the abutted steel strip and cut to a fixed length When manufacturing steel pipes,
Production of the steel strip every time within the range of the length of the secondary processed part that is produced by further cutting the steel pipe of the predetermined length on the surface of the steel strip that is unwound and becomes the inner surface of the steel pipe after forming. The information is printed or stamped, and the computer stores the welding conditions, nondestructive inspection results, annealing conditions, and defective part marks corresponding to the printed or stamped positions applied in the subsequent processes. Manufacturing history management method for steel pipe. Instead of printing or engraving steel strip manufacturing information according to claim 1, the welding conditions, nondestructive inspection results, annealing conditions, and marks of defective parts are separately stored on the inner surface or outer surface of the steel pipe having the predetermined length. A manufacturing history management method for steel pipes, characterized by attaching a microchip. The steel pipe manufacturing history management method according to claim 1, wherein the steel pipe is an electric resistance steel pipe. The steel pipe manufacturing history management method according to any one of claims 1 to 3, wherein the secondary processed part is an automobile part.

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