METHOD OF QUALITY CONTROL OF BUTT-WELDED JOINTS BY BURN-OFF, AND DEVICE FOR IMPLEMENTATION THEREOF

摘要

FIELD: welding.;SUBSTANCE: invention relates to a method and device for flash butt welding by burn-off of pipes and can be used to control the quality of welded joints in the manufacture of pipelines. Parameters of the signals characterizing the quality of the welded joint are measured, 10–30 s after the end of welding, when the temperature of 800–900 °C is reached in the welded joint after the welding machine forms one or several short impulses of force in the form of a tensile stress of 0.5–0.7 of the yield strength of the metal being welded. Device contains a transducer of acoustic signals, a preamplifier, a band-pass filter, an analogue-digital converter, an amplitude discriminator, a block of RAM, a block of reference signals, a unit for calculating the normalized correlation function, a filtering unit for the correlation coefficient level; a discriminator of the rejection level, and an industrial computer with an output display monitor. Transducer of acoustic signals is made with the possibility of providing acoustic contact with the surface of the welded pipes. First input of the normalized correlation function calculation unit is connected to the output of the main memory unit, and its second input is connected to the output of the reference signal unit. Output of the discriminator of the rejection level is connected to the above-mentioned industrial computer, which is connected to the hydraulic cylinder of the draft. Photographic pyrometer is designed to measure the temperature in the weld area and transfer measurement results to an industrial computer.;EFFECT: technical result consists in expanding the arsenal of technical means for quality control of flash butt welding of pipes by burn-off and increasing the accuracy of quality control.;2 cl, 1 dwg