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Home >News >Industry News >Applications of Fully Automatic Ultrasonic Inspection to Welding Seams of Carbon Steel Pipelines (Part One)

Applications of Fully Automatic Ultrasonic Inspection to Welding Seams of Carbon Steel Pipelines (Part One)

Posted: 10/05/2021 13:12:10 Hits: 24

Abstract
Automatic Ultrasonic Testing (AUT) has become the preferred testing method for welding seams of carbon steel pipes due to its high efficiency, accuracy and environmental protection. However, AUT is difficult to apply to the inspection of pipelines with a diameter of 114.3 mm (4 inches) and below due to the geometric constraints of the AUT scanning device. However, the application of submarine pipes of 4 inches has become more and more widespread due to the gradual development of underground resources to deeper areas. In this regard, in order to verify whether the AUT detection technology can be applied to the carbon steel pipeline, 5 pipes with a diameter of 114.3 mm (4 inches) and a welding seam with a wall thickness of 6.4 mm are processed. 5 artificial defects are created for each welding seam. There are 25 artificial defects in total. The defect locations cover the root, filling and cover area of the welding seam. The AUT detection technology is used for detection, data analysis, and macroscopic slicing. Finally, the AUT inspection data and macro slice data are compared and analyzed to evaluate the detection ability for the defect and high quantitative accuracy of the AUT inspection technology in the workpiece with a diameter of 114.3 mm (4 inches).

As underground energy development continues to advance to deeper areas, pipes with more and more specifications are used for underground pipelines, usually ranging from 60.3 mm (2 inches) to 1066.8mm (42 inches). Automatic ultrasonic inspection technology (AUT) has gradually become the preferred inspection for welding seams of carbon steel pipelines with its advantages of high efficiency, accuracy and environmental protection. However, the AUT inspection process is usually difficult to be used for inspecting pipelines with a diameter of 114.3 mm (4 inches) and below due to the curvature of the pipeline and geometric limitations of the AUT scanning device.

In order to verify the ability of AUT detection technology for detecting various dangerous surface defects in the pipe with a diameter of 114.3 mm. Use the adjusted AUT detection technology to detect and analyze the above 5 welding seams to evaluate the detection ability of the AUT detection technology and the high quantitative accuracy of the defects based on the created 5 pipes with diameters of 114.3 mm (4 inches) and artificial defected welding seams with a wall thickness of 6.4 mm (25 artificial defects in total).

1. An introduction to AUT
Fully automatic ultrasonic inspection technology (AUT) was also known as the inspection technology for the weld zone in the early days. This inspection technology needs to divide the welding seam into areas with lengths of 2 mm to 3 mm in the wall thickness direction according to the groove form and wall thickness of the welding seam to be inspected (as shown in Figure 1 below). Combined with multiple sets of sound beam configuration methods, a set of independent sound beams is used for detecting each partition of the welding seam to achieve the purpose of full coverage of the entire welding seam area.

Figure 1 The schematic diagram of the welding seam zone

Aiming at the specifications of carbon steel pipes with a diameter of 114.3 mm and a wall thickness of 6.4 mm, AUT testing process development and ultrasonic focusing law simulation are conducted. The relevant simulation is shown in Figure 2. The AUT process calibration block design is performed. The relevant block design is shown in figure 3.

Figure 2 The schematic diagram of AUT focusing law simulation

Figure 3 The diagram of the AUT calibration block

2. Preparation for the test
There are five man-made defected welding seams on pipes with a diameter of 114.3 mm and a wall thickness of 6.4 mm, and there are five man-made defects on each welding seam, that is, 25 defects. The defect distribution and locations on the welding seam are shown in Figure 4 and Figure 5.

Figure 4 The schematic diagram of the defect distribution of the welding seam

Figure 5 The schematic diagram of the defect locations

The main types of artificial defects are lack of welding, fusion on the side walls, fusion between layers, fusion on the cover surface as well as dense gas holes. The defect distribution areas are mainly the root area, filling area and covering area of the welding seam. The distribution of defects of welding seams is shown in Table 1.

Table 1 The distribution and quantity of artificial defects

Welding seam areas	Defect types	The quantity of defects
Welding seam areas	Defect types	W1	W2	W3	W4	W5	Total
The root	Lack of welding	-	3	-	2	2	7
Filling	Lack of fusion on the side walls	2	1	-	3	-	6
	Lack of fusion between layers	-	1	1	-	1	3
	Dense gas holes	-	-		-	2	3
The cover surface	Lack of fusion on the cover surface	3	-	3	-	-	6
Total		5	5	5	5	5	25

Post URL: https://www.landeepipe.com/applications-of-fully-automatic-ultrasonic-inspection-to-welding-seams-of-carbon-steel-pipelines-part-one.html

Landee Pipe is a professional industrial pipe manufacturer based in China, we have been producing pipe for a variety of applications, and covering areas of pipe manufacturing, exporting and trading. welcome to access our website: https://www.landeepipe.com.

Next: Applications of Fully Automatic Ultrasonic Inspection to Welding Seams of Carbon Steel Pipelines (Part Two)

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About the author

Teresa

Teresa is a skilled author specializing in industrial technical articles with over eight years of experience. She has a deep understanding of manufacturing processes, material science, and technological advancements. Her work includes detailed analyses, process optimization techniques, and quality control methods that aim to enhance production efficiency and product quality across various industries. Teresa's articles are well-researched, clear, and informative, making complex industrial concepts accessible to professionals and stakeholders.