A detection method for steel structure welding quality defects

Abstract

The invention discloses a detection method of welding quality defects in steel structures. According to the detection method, welding portions are divided into three types, namely planar welds, cambered welds and corner welds, and pulse reflection detection is performed respectively by using phased array ultrasonic detection equipment as well as a high-frequency probe, a double crystal probe and alow-frequency probe; when the planar welds are detected, the low-frequency probe is used for performing phased array ultrasonic primary probing detection first, and then the high-frequency probe is used for performing secondary probing detection; when the cambered welds are detected, the low-frequency probe is used for performing phased array ultrasonic primary probing detection first and then the double crystal probe is used for performing double crystal phased array detection; and when the corner welds are detected, the double crystal probe is used for performing double crystal phased arraydetection first, and then the low-frequency probe is used for performing phased array ultrasonic primary probing detection. The detection method of the welding quality defects in the steel structuresefficiently uses different stabilities and precisions of different probes in detection of different welds for performing mutual calibration and further making results precise, and the detection method has the advantages of low detection cost, high applicability and accurate detection structure.

Description

technical field [0001] The invention relates to safety detection technology in the field of construction engineering, in particular to a detection method for steel structure welding quality defects. Background technique [0002] As the economic construction enters a stage of rapid development, the engineering structure is developing in the direction of oversized and complex, and the application of steel structures in construction projects is becoming more and more extensive. There are more and more structures, and the use of high-strength steel with higher strength grades is also an inevitable trend in the development of building steel structures. The connection part occupies an important position in the steel structure, and the processing and assembly of steel components to form a structure must be realized through connection. The structure and stress of the connection are relatively complicated, and often become the weak link of the structure, while the quality of the con...

AI Technical Summary

Problems solved by technology

However, the steel used in the construction steel structure industry has a single variety, few types of alloy elements, low content and low strength. It is clearly stipulated in the selection requirements for relevant steel materials in GB50011-2010 "Code for Seismic Design of Buildings" that construction steel materials should have good weldability And qualified impact toughness, and has good weldability. In addition, because the welding process itself is simple and easy to operate, the welding technology is not difficult, so the industry has relatively low requirements for welding technology, resulting in low industry threshold. This leads to uneven quality of welded steel structures

Since the promotion of welded steel structures, there have been frequent damage accidents of welded steel structures, and one of the main problems of welding quality is weld defects. Surface or internal defects, such defects are easy to appear in the weld and its vicinity, and it is the place where the tensile residual stress is the largest in the steel structure. Most steel structures are very important load-bearing structures. These welding defects The effective area of ​​the structural load-bearing cross-section is reduced, and stress concentration occurs around the defect, resulting in the simultaneous existence of stress and deformation, which reduces the strength of the welded structure, which has a very obvious adverse effect on the bearing capacity of the steel structure. Can cause sabotage accidents and cause heavy loss of life and property