METHOD OF QUALITY CONTROL OF WELDED JOINTS Russian patent published in 1994 - IPC

FIELD: technical physics. SUBSTANCE: casette with a film is located in the gap between the inductor surface and the tubes. When the inductor is connected to the power supply, in the tube walls through a butt joint is induced a current contour rotating behind the field and exhaling heat in the material of the tube walls and the weld exciting their infra-red luminosity in the range corresponding to the desired temperature. If there are no defects in the weld material, the heat is uniformly distributed along the whole cross-section of the weld forming uniform exposure of the film by infra-red radiation. If there are defects whose resistance is different from that of the metal of the weld and of the tubes, the heat distribution along the weld cross-section corresponds to the current value along the corresponding cross-sections, resulting in picking out the sections of defects by means of smaller radiation and its less frequency. As the contact exposition is exercised as a result of the film exposure, these defects are depicted as corresponding to the form, size and location of spots on the developed film which enhances the information content and efficiency of control. EFFECT: enhanced information content at the expense of revealing the nature of size and location of defects along the weld as well as enhanced efficiency of control. 7 dwg