The main procedures of LSAW longitudinal welded steel pipe automatic ultrasonic testing process flow include: system startup, welded pipe feeding, welded pipe transmission, welded pipe rotation, welded pipe clamping and positioning, weld flaw detection, spray marking, welded pipe clamp loosening, welded pipe sorting, welded pipe discharging, etc. The specific process is as follows:
System startup: after pressing the startup button. The flaw detection system is powered on; If the power supply voltage detection is normal, start feeding the welded pipe: if the voltage detection is abnormal, the alarm will send an alarm signal and cut off the power supply.
Welded pipe positioning: after the pressure sensor detects that the welded pipe reaches the conveying track through the feeding system. Start feeding the welded pipe; After the welded pipe touches the travel switch at the front end of the pipe, the steel pipe feeding stops; Rotate the steel pipe so that the weld is at 12 o’clock; Then clamp the steel pipe with the pipe welding fixture.
Weld flaw detection: when the welded pipe clamping test is normal, the coupling agent starts to spray, the ultrasonic detection probe is pressed down to contact the welded pipe body, and the welded pipe worker enters and starts flaw detection; If there are defects in the weld, stop the welding of the welded pipe, lift the probe and spray the identification; After that, the probe is pressed down again, the steel pipe is processed and flaw detected until the end of the welded pipe touches the travel switch at the end of the pipe, the process is stopped, the coupling agent spraying is stopped, and the probe is lifted and reset. After that, the welded pipe fast forward to the welded pipe sorting mechanism.
Sorting of welded pipe: stop fast forward of welded pipe and loosen the welded pipe clamp; Photoelectric sensor detects whether the welded pipe has defect identification. If there is a defect identification signal input, the welded pipe will be transmitted forward to the outlet of the damaged pipe; If there is no defect identification signal input, the steel pipe will be discharged directly to the outlet of qualified welded pipe. At this point, one process ends and the next cycle begins.
The program control points of LSAW automatic ultrasonic testing are as follows: press the start button, the power supply of the main circuit of the system is connected, and the power supply voltage is detected to be normal, then each control relay is connected successively according to the sequence under the corresponding command of PLC. The procedures of automatic ultrasonic testing are carried out successively. After flaw detection and blanking of a welded pipe, each control relay has been disconnected successively. After a flaw detection cycle is completed, the system will automatically reset and prepare for the detection of the next welded pipe. When the detection process is abnormal, press the emergency stop button to disconnect the system power immediately, so as to avoid damage to the equipment.
PLC is applied to the automatic ultrasonic testing of LSAW straight seam welded steel pipe, which makes the testing operation convenient and improves the testing accuracy and efficiency; Equipment maintenance can accommodate the increase of plate thickness, large temperature gradient and uneven metal plastic flow along the plate thickness direction. Therefore, optimizing the design of stirring head and adding auxiliary heat source can improve the quality of FSW thick plate high-strength aluminum alloy joint. The simulation of temperature field, flow field and microstructure of FSW can analyze the welding mechanism and optimize the welding process parameters. And reduce the test funds. However, the research direction of numerical simulation is to integrate the temperature field, flow field and solid mechanics models into one model to simulate the FSW process.
Post time: Jan-14-2022