METHOD OF ACOUSTIC EMISSION QUALITY CONTROL OF GIRTH WELD DURING MULTIPASS WELDING AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2015 - IPC G01N29/14 

FIELD: metallurgy.

SUBSTANCE: preliminary calibration of the controlled object by installation along the weld contour at least four wide-band transducers, weld is divided to equal sectors, coordinates of the acoustic signals are determined in polar system, wherein the polar axis passes along border between the sectors, each sector is within where m is number of sectors of girth weld; i is current sector; φ is polar angle, rad, in each sector distribution of the energy parameter MARSE equal to is determined, where U(t) is voltage of acoustic signal envelope, V; T is set time period, s, and number of oscillation in the acoustic signal, they are compared with reference distributions at defects free area of the weld, and upon exceedance of the reference values in any sector the weld is rejected.

EFFECT: assurance of possibility to increase authenticity of defects control and accuracy of defects rejection in the girth welds.

3 cl, 2 dwg