1. Radiographic inspection of welded steel pipes is a non-destructive testing method used to detect internal defects in welds of welded steel pipes. It uses the penetration characteristics of rays (usually X-rays) to image the weld, thereby identifying and evaluating whether there are defects such as pores, slag inclusions, cracks, etc. inside the weld. This method can provide detailed images of the inside of the weld and is one of the important means to ensure welding quality.
2. Radiographic inspection technology
Radiographic inspection technology includes two main methods: radiographic film inspection and radiographic digital inspection. The standards for radiographic film inspection include ISO10893-6 image quality level A or B, or ASTME94; while radiographic digital inspection is based on SY/T6423.5-2014, ASTME2698 or ASTME2033 standards.
3. Radiographic inspection equipment
The selection and use of radiographic inspection equipment is the key to ensuring the inspection effect. The uniformity of the weld should be inspected by radiographic inspection method, which is: X-rays directly penetrate the weld material and produce suitable effects on the radiographic inspection film or digital imaging medium. Digital imaging technology needs to be proven to be able to achieve the required sensitivity. The radiographic inspection film used should comply with GB/T19348.1-2014 C4 or C5, or ASTME1815-08 I or II, and a lead intensifying screen should be used.
4. Image Quality Indicator (IQIS)
The image quality indicator (IQIS) is used to verify the sensitivity and imaging quality of the radiographic inspection system. A linear image quality indicator is usually used, and its basic wire diameter is selected according to the weld thickness. The linear image quality indicator should be placed across the weld on the weld representing the complete excess height and contain two basic wire diameters, one determined by the thickness of the weld with complete excess height and the other determined by the thickness of the weld without excess height
5. Application areas
Radiographic inspection of welded steel pipes is widely used in industries such as petroleum, natural gas, and chemicals, especially in pipeline systems that require high safety and reliability. For example, the GB/T9711-2023 standard is applicable to weld inspection of steel pipes used in pipeline transportation systems in the oil and gas industry.
Conclusion
Radiological inspection of welded steel pipes is a key non-destructive testing technology that ensures the safety and reliability of pipeline systems by accurately detecting internal defects in welds. With the development of technology, digital radiographic inspection is gradually becoming the mainstream, providing higher sensitivity and more convenient data processing methods.
