RU2209426C2 - Automated facility of ultrasonic quality inspection of pipes - Google Patents

Abstract

FIELD: nondestructive testing means realizing ultrasonic immersion echo-pulse flaw detection method, automated quality inspection of steel seemless pipes. SUBSTANCE: automated facility includes ultrasonic inspection mechanism comprising base, bracket, lifting unit of spring-loaded immersion bath with electroacoustic converters. Immersion bath is linked through spring-loaded telescopic tie-rod to axle of bracket anchoring on one side and is joined through guides to guiding frame on other side. Electroacoustic converters are connected to flaw detectors and thickness meter which outputs are connected to inputs of adapter, outputs of the latter are connected through coprocessor to computer and through control unit to lifting unit of immersion bath and actuators. Electroacoustic converters of flaw detectors are displaced over length one relative another. Facility can include several ultrasonic inspection mechanisms, thickness meters and flaw detectors. EFFECT: increased reliability and efficiency of quality inspection of pipes. 2 cl, 6 dwg

Description

 The invention relates to non-destructive testing means that implements an immersion echo-pulse method of defectoscopy and can be used to control the quality (body continuity and pipe wall thickness) of seamless steel pipes in production lines at pipe plants and before operation.

 Known automated ultrasonic installation "Bur-1M" for pipe inspection [1, 2], containing electronic-acoustic and electronic-mechanical parts.

 The electronic-acoustic part includes flaw detectors and a thickness gauge with a mechanism for moving acoustic blocks to control the pipe body and two flaw detectors to control the threaded part of the drill pipe.

 The electronic-mechanical part includes a device for cleaning pipes before control, a pipe rotation mechanism during control, and an electric power cabinet with a control panel.

 The pipe is installed in the control zone and is controlled by electro-acoustic transducers (EAP) suspended from the carriage, which is lowered onto a rotating pipe. Under each converter water is supplied.

 Such a plant is used for pipe quality control days at pipe plants. The disadvantage of this device is the low performance and reliability of the control.

 A device for ultrasonic pipe quality control "Atlant-3" UK-12I, which is used in production lines of pipe plants [3]. It consists of an electronic stoic and an ultrasonic testing mechanism (ultrasonic testing). The electronic rack [4] contains flaw detectors, a thickness gauge, an automation unit, and a flaw detector.

 The ultrasonic control mechanism [5] contains a bracket on which springs are mounted for installing an immersion bath with combined EAP. The bracket is pivotally mounted on axes connected to the base and is spring-loaded to the latter. At the ends of the two-arm levers, conical follower rollers are fixed. The second ends of the two-arm levers are pivotally connected to an additional two-arm lever mounted on an axis rigidly connected to the bracket.

 The arms of the levers with tracking rollers at the ends are mounted on the axles with the possibility of adjustment along them and by the angle of inclination, and are fixed by clamps. There is an emphasis to adjust the initial position of the immersion bath. There is a special mechanism for fixing the immersion bath, including a hinge and telescopic traction, through which the immersion bath is connected to the base. The axes of the tracking rollers are fixed on the axes perpendicular to them, mounted on two-arm levers.

 The device operates as follows. When the controlled pipe (which moves translationally-rotationally) approaches the first follower roller, the latter, due to its conical shape, rises and turns its two-arm lever, and connected to the first through the second additional two-arm lever, the second lever turning in the direction opposite to the first, when this second tracking roller is lowered. The bracket with the immersion bath installed on it is in the lower position and is supported by an adjustable stop, and only when the controlled pipe acts on the second follower roller, the bracket, turning on its axes, raises the immersion bath, pressing it through the springs to the controlled pipe. The pipe control process begins. The contact between the transducer and the surface of the pipe is carried out using water filling the immersion bath. Information on the results of the control (in the presence of defects) is issued in the form of light and sound alarms, recording on a recording device and marking the defective pipe section using paint markers.

 When the end of the pipe passes under the first follower roller, the latter descends and makes it possible under its own weight to the bracket with the immersion bath to lower to its original position, in which the immersion bath is under the lower edge of the controlled pipe.

 The immersion bath consists of a welded bath, inside of which are placed in the EAP hinges. The immersion bath is monitored by the surface of the controlled pipe by an orientation mechanism, including four orienting rollers mounted on the carriages, and screws pivotally mounted to each other, on which the carriages are mounted to move along them. At the same time, the immersion bath is restructured to various pipe diameters.

 On the set of essential features, the device [3], also described in [4, 5], is a prototype of the claimed device.

 The presence in the known device of two-arm levers, spring-loaded relative to the base, tracking and rotating rollers complicates the design and reduces the reliability of the device under the influence of water, which leads to downtime of the pipe control line and a decrease in productivity.

 The insufficiently high degree of tracking of the immersion bathtub of the moving pipe leads to the disappearance of the acoustic contact and the passage of defects, which reduces the reliability of the control.

 The lack of digital information processing leads to pipe rejection due to failures in the analog units of flaw detectors and thickness gauge and, ultimately, to a decrease in the reliability of control.

 Documenting the results of control mechanically increases the loss of time for maintenance of recorders and reduces the performance of the control line.

 The purpose of the invention is to obtain the following technical result - to increase the reliability and productivity of pipe control by changing the design of the mechanical part and its electronic control, optimizing the placement of the EAT in the immersion bath and digitally processing the results of the measurement process.

 This technical result is achieved by the fact that the bracket is connected to the lifting unit of the immersion bath, the telescopic rod is spring-loaded, the opposite side of the immersion bath is connected to the guide frame through the guides. Cams with inserts are installed on the guides of the immersion bath, the information outputs of the flaw detectors, the thickness gauge and the pipe presence sensor are connected to the inputs of the adapter, the outputs of which are connected through the coprocessor to the computer and, through the control unit, to the immersion bath lifting unit and actuators, and the electro-acoustic thickness gauge transducer is located near the wall of the immersion bath farthest along the pipe parallel to the horizontal section of the pipe coaxially with the vertical diametrical section of the pipe.

 EAP flaw detectors are shifted in length relative to each other by up to 50% of their length.

 The composition of the proposed device may include N ultrasonic testing mechanisms, N thickness gauges, 2N flaw detectors, N pipe presence sensors, where N = {2, 3, ...}.

 Figure 1 shows the electrical structural diagram of the proposed device, figure 2, 3, 4 are drawings of the ultrasonic inspection mechanism, front, top, side views, respectively, in Fig. 5, 6 - printouts of the protocols of the results of control of the body and wall thickness of one pipe, respectively.

 The proposed device contains a UZK mechanism 1 (Figs. 1, 2, 3, 4), consisting of a base 2, on which an arm 4 is mounted on the axis 3. An immersion bath 6 is mounted on it on spring fingers 5. In Figs. 2, 3, 4 - immersion bath is shown in a raised position. On the one hand, the immersion bath 6 is connected through the spring rod 7 to the axis 3. On the opposite side, the immersion bath 6 is connected through the guides 8 to the guide frame 9. Cams 10 are installed on the guides 8 with guide inserts 11 made of wear-resistant material along which the pipe 12 moves The lower part of the bracket 4 is connected to the lifting unit 13 of the immersion bath 6. In the immersion bath 6 are mounted on ball bearings two combined EAFs 14 of the flaw detector 15 and one combined EAF 16 of the thickness gauge 17. Information the output outputs of the flaw detectors 15, the thickness gauge 17 and the pipe presence sensor 18 (Fig. 1) are connected to the inputs of the adapter 19, which is connected to the coprocessor 20, the latter is connected to the computer 21. The outputs of the adapter 19 are connected to the control unit 22, the outputs of which are connected to the lifting units 13 immersion baths and actuators 23.

 The device operates as follows. The mechanism of ultrasonic testing 1 is installed in the production line. In the initial position, the immersion bath 6 is in the lower position. Controlled pipes move in a production line along the rolling table translationally-rotationally. When the front end of the pipe approaches the presence sensor of the pipe 19, the latter generates the corresponding signal through the adapter 19 to the coprocessor 20. After the time t necessary for the front end of the moving pipe to reach the edge of the immersion bath far in the direction of the pipe’s movement, the coprocessor 20 through the adapter 19 and the control unit 22 gives a command to the lifting unit 13 of the immersion bath 6, which is triggered, raises the bracket 4 with the immersion bath 6 and presses the latter against the moving pipe. The controlled pipe moves through the immersion bath 6 in a semi-submerged position in the water.

 The signals from the EAP 14 are fed to the flaw detector 15 and then to the adapter 19, where they are converted to digital form and transmitted through the data bus to the coprocessor 20. The time between the reflected surface and bottom pulses, as well as between the bottom pulses with the EAP 16 in the thickness gauge 17, is converted to pulse duration, which is proportional to the pipe wall thickness. These pulses are supplied to the adapter 19, where they are converted into codes that are supplied to the coprocessor 20, where the primary processing of information occurs. Information on defects in the pipe body and pipe wall thickness is highlighted. Based on the application program stored on the computer 21 hard drive, digital information processing is carried out, real-time results are displayed on the computer screen 21 and the processed information is stored in the database. Before control, the computer 21 enters the necessary initial data: date, workshop numbers, shifts, pipe lots, pipes, melts, average pipe diameter and wall thickness, operating mode, display scale of information on the monitor, digital filtering coefficients, repetition of defects, thickness tolerances pipe walls. If necessary, information about the results of the control can be printed on a printer.

 After the end of the monitored pipe passes the sensor for the presence of the pipe 18, after time t from the adapter 19 through the control unit 22, a command is issued to the lifting unit 13 of the immersion bath 6, along which the immersion bath is lowered. As the next pipe approaches, the control process repeats.

 If there is a defect in the pipe body or the pipe wall thickness falls outside the tolerance field, the corresponding codes are generated in the coprocessor 20, which enter the adapter 19, where they are converted into the corresponding commands, which are transmitted to the actuators 23 through the control unit 22, and the latter mark the rejected places with paint on a controlled pipe and include a pipe ejector in the scrap pocket.

 EAP 14 are placed in the immersion bath 6 with a shift in length relative to each other by up to 50% of their length of the EAP 14 (see figure 3). This allows you to increase the control step of the pipe, increase the translational speed of the pipe and, ultimately, increase the productivity of the device. The value of the shift EAP 14 is determined by the required control step.

 The EAA 16 is located near the wall of the immersion bath 6, which is far in the direction of the pipe and is parallel to the horizontal section of the pipe coaxially with the vertical diametrical section of the pipe.This arrangement allows to reduce the clogging of the plane of the EAA 16 by scale from the controlled pipe and to increase the reliability of control.

Setting EAP 14 of the flaw detector 15 when changing the diameter of the controlled pipes is made in the following order. When the immersion bath 6 is raised, the position of the fists 10 is changed (they are moved along the guides 8) so that the controlled pipe lies symmetrically on the immersion bath 6. EAP 14 is installed at an angle of (18-20) ^o to the diameter of the pipe. The position of the EAF is adjusted using a short test sample with an artificial defect in the form of longitudinal risks. The exact position of the EAA 14, 16 is determined by the maximum values of the signals from the artificial defect and the bottom pulse, respectively.

 The introduction into the device of several identical mechanisms of ultrasonic testing device 1, flaw detectors 15, thickness gauges 17, sensors for the presence of the pipe 18 can reduce the time control pipe, which increases the productivity of the installation. For example, the introduction of two mechanisms of ultrasonic testing 1, four flaw detectors 15, two thickness gauges 17 and sensors for the presence of pipe 18 reduces the time of monitoring the pipe by half. The mechanisms of the ultrasonic testing device 1 are located on the roller table at a distance equal to half the length of the pipe. The controlled pipe from the splitter is fed to the roller table so that the beginning of the pipe is located in front of the second UZK 1 mechanism (counting along the pipe), and the middle of the pipe is in front of the first UZK mechanism. After the front end of the pipe approaches the second sensor for the presence of pipe 18, the pipe monitoring mode is activated. After the rear end of the pipe passes the first sensor of the presence of the pipe 18, the control mode ends and the controlled pipe is transferred to the pocket of suitable or unusable pipes. The principle of operation of the device itself does not change. Thus, the introduction into the device of N mechanisms of ultrasonic testing 1, N thickness gauges, 2N flaw detectors, N sensors of the presence of the pipe can increase the productivity of the device N times. The value of N is determined by the speed of movement of the pipes in the stream according to the technological process of their production and is generally equal to N = {2, 3, ...}.

 The proposed device is manufactured and tested in a pipe rolling workshop. Combined piezoelectric transducers with a width of 10 mm, a length of 80 mm, 100 mm, and 120 mm were used as an EAP of 14 flaw detectors; a combined piezoelectric transducer of a cylindrical shape with a diameter of 10 mm was used as an EAP 16 of a thickness meter. Immersion bath 6, guides 8, cams 10 are made of stainless steel. Immersion baths with a width of 150 mm and 200 mm were tested.

 As flaw detectors 15 and thickness gauge 17, electronic components were used: clock generators, ultrasonic radio pulse generators, receiving and amplifying paths, ultrasonic radio pulse generators made on transistors and microcircuits.

 The lifting unit 13 of the immersion bath 6 is implemented as a pneumatic valve; an electron-optical sensor is used as a sensor for the presence of coarse 18.

 The adapter 19 and the coprocessor 20 are made in the form of blocks on integrated circuits, as a computer 21 used a personal computer based on "Pentium-2". The control unit 22 is a set of thyristors and relays for generating control commands. Actuators 23 are paint strippers and pneumatic cylinders for controlling pipe ejectors.

 The tests were carried out on several batches of pipes 12 m long, with a diameter of 89 mm, 146 mm, 219 mm with a three-shift operation of the production line and confirmed an increase in the reliability and productivity of pipe inspection of the proposed device.

List of literature
1. Devices for non-destructive testing of materials and products. Directory. In 2 books. Prince 21 ed. V.V. Klyueva - 2nd ed., Rev. and add. - M: Mechanical Engineering, 1986, p. 328.

 2. Shalashov G.I., Beloborodov V.I. Automated ultrasonic installation "BUR - 1M" for the control of drill and casing pipes. - Defectoscopy 1976, 1, p.138.

 3. The device of ultrasonic non-destructive testing ATLANT - 3 UK - 12I. Operation manual ЩУ 2.075.022 РЭ VNIINK, Chisinau, 1988.

 4. Passy S.X., Chegorinskaya O.N., Shumila L.N. Information on fixed assets of ultrasonic non-destructive testing of mass production. - Defectoscopy, 1984, 8, p. 93.

 5. The device for ultrasonic testing of cylindrical products. A.S. 1083106 dated 07.15.81 IPC G 01 N 29/04.

Claims (3)

 1. An automated device for ultrasonic pipe quality control, comprising an ultrasonic control mechanism, consisting of a base, a bracket, on the free end of which a spring-loaded immersion bath is installed, connected by a telescopic rod to the bracket mounting axis, in which electro-acoustic transducers of flaw detectors and thickness gauge are installed, a control unit and an executive device, characterized in that the bracket is connected to the lifting unit of the immersion bath, the telescopic rod is made spring-loaded, the opposite side of the immersion bath is connected via guides to the guide frame, cams with inserts are installed on the immersion bath guides, information outputs of flaw detectors, thickness gauge and pipe presence sensor are connected to the adapter inputs, the outputs of which are connected through the coprocessor to the computer and, through the control unit, with the immersion bath lifting unit and actuators, and the electro-acoustic transducer of the thickness gauge is located near the immersion wall farthest along the pipe the bathtub parallel to the horizontal section of the pipe coaxially with the vertical diametrical section of the pipe.  2. The device according to claim 1, characterized in that the electro-acoustic transducers of flaw detectors are shifted in length relative to each other by up to 50% of their length.  3. The device according to claim 1 or 2, characterized in that it contains N ultrasonic inspection mechanisms, N thickness gauges, 2N flaw detectors, N pipe presence sensors, where N = {2,3 ...}.

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