Method used for detecting welding quality of welding carried out in intermediate layer connection manner

Abstract

The invention belongs to the field of nondestructive testing ultrasonic flaw detection, and discloses a method used for detecting welding quality of welding which is carried out in an intermediate layer connection manner. According to the method, ultrasonic longitudinal wave reflection type liquid immersion technology is adopted; a focus is focused on a connection interface, sensitivity is maintained unchanged; a scanning mechanism is moved along different axial directions on a detecting surface; echo wave amplitudes of the connection interface are observed; a welding complete zone with a lowest echo wave amplitude is found; sensitivity is adjusted to a value that the echo wave amplitude of the welding complete zone accounts for 45 to 55% of full screen amplitude; scanning on a whole workpiece is carried out with the sensitivity value; and calculation and evaluation on the workpiece are carried out based on a defect determination criterion, wherein according to the defect determination criterion, the echo wave amplitude of the connection interface is more than 80% of the full screen amplitude. No extra reference test piece is needed by the method; detection cost is reduced greatly; ultrasonic detection processes are simplified; detection time is saved; and detection efficiency is increased.

Description

technical field

[0001] The invention belongs to the technical field of non-destructive testing ultrasonic flaw detection, and in particular relates to a method for testing the welding quality of welding using an intermediate layer connection mode. Background technique

[0002] Welding technology is an operation method that uses welding materials (welding rods or wires) to connect two or more base materials (workpieces to be welded) into a whole under high temperature or high pressure conditions. Welding methods are divided into three categories: fusion welding, pressure welding and brazing. The welding method using the middle layer connection belongs to brazing. During the welding process, there are some discontinuities in the welding area that degrade the performance of the joint area, such as cracks, slag inclusions, oxide inclusions, wrinkles, metal inclusions, holes, lack of welding, lack of fusion, incomplete penetration, undercut, burning These discontinuities are col...

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