Characteristic Analysis Of Three-dimensional Full-focus Phased Array Imaging Of Typical Butt Weld Defects

Welding is an important manufacturing process and technology,in all kinds of equipment are more commonly used.There will be welding defects in the weld,for some sealing requirements,high-pressure components,etc.,the quality of the weld needs to be tested.Weld quality inspection has always been a difficult problem to be solved in industry,and new technology has been applied to weld inspection.In this paper,3d full focus phased array imaging technology is used to detect the typical defects of butt weld.Firstly,a simulation model of phased array beam was built.The simulation parameters of ultrasonic phased array,such as excitation signal,array number,array width,array spacing and deflection Angle,were analyzed by focusing acoustic beam effect,and the optimal parameters were obtained.Through the simulation model of butt weld inspection by direct method,it is concluded that when the defect is located near the bottom side,it can be detected by direct wave.Butt weld detection model by secondary reflection wave method simulation that the shear wave has good directivity,and transmitted energy is larger,a second wave detection has a wide coverage,can prevent leak phenomenon,but due to the particularity of model structure and material,ultrasonic energy attenuation is bigger,should not be used for the butt weld inspection.After analyzing the causes,appearance characteristics and positions of welding defects,three butt weld test blocks of carbon steel,dissimilar steel(carbon steel and austenitic stainless steel)and austenitic stainless steel were designed and manufactured,and four typical defects such as non-fusion,crack,porosity and slag inclusion were added to the weld.Cts-pa322 t phased array full-focus real-time 3D ultrasonic imaging system was selected to conduct an experimental study on the defects in the welding seam of each butt test block by using direct irradiation method.Based on the experimental results,the characteristics of 3d fully focused phased array imaging spectrum corresponding to each typical defect were analyzed in detail,as well as the influence of different material butt welds on the detection results.By conventional ultrasound,three-dimensional full focus on phased array,two-dimensional full focus on phased array,radiation and so on four kind of detection method for the quantitative comparison found that 3d full focus on phased array of carbon steel,typical of dissimilar steel weld defect detection effect is good,the error is small,austenitic stainless steel due to reasons such as material,detection error from the previous two.Affected by the defect characteristics,it can be seen from the overall comparison that the detection errors of the four typical defects of non-fusion,crack,porosity and slag inclusion increase successively.