What is KS B 0845 and how does it relate to radiographic testing
KS B 0845 is a Korean standard that specifies the methods and requirements for radiographic testing of welded joints in steel plates and pipes. Radiographic testing is a non-destructive testing technique that uses X-rays or gamma rays to detect defects in materials. Radiographic testing can reveal cracks, porosity, slag inclusions, lack of fusion, and other flaws that may affect the quality and performance of welded joints.
The standard KS B 0845 covers the following aspects of radiographic testing:
The classification of radiographic image quality into five grades: A, B, P1, P2, and F. Grade A is obtained by using conventional shooting techniques, while grade B is obtained by using shooting techniques that enhance defect detection sensitivity. Grade P1 is obtained by shooting one side of a circumferential weld joint with double-wall penetration, while grade P2 is obtained by shooting both sides of a circumferential weld joint with double-wall penetration. Grade F is obtained by shooting T-weld joints with single-wall penetration.
The direction of radiation exposure, which should be perpendicular to the plane of the weld joint and minimize the thickness of the test piece.
The use of penetrameters and densitometers to measure and control the density and contrast of radiographic images. Penetrameters are thin metal strips with holes or wires of different diameters that are placed on both sides of the test piece to indicate the minimum detectable hole or wire diameter. Densitometers are devices that measure the optical density of radiographic images by comparing them with standard density scales.
The placement of source, penetrameters, densitometers, and film according to the geometry and thickness of the test piece and the image quality grade.
The observation and evaluation of radiographic images using viewers and classification criteria. Viewers are devices that provide uniform illumination and magnification for viewing radiographic images. Classification criteria are rules for identifying and grading defects based on their shape, size, location, and density on radiographic images.
The recording and reporting of radiographic testing results, including information about the test piece, the shooting conditions, the image quality requirements, the defect classification results, and any other relevant data.
KS B 0845 is a useful standard for ensuring the quality and reliability of welded joints in steel plates and pipes using radiographic testing. It provides clear and consistent guidelines for conducting and interpreting radiographic tests in accordance with international standards and best practices.Radiographic testing has many applications in various industries and sectors, such as:
Oil and gas: Radiographic testing can be used to inspect pipelines, valves, welds, and other components for corrosion, cracks, erosion, and other defects that may cause leaks or failures.
Aerospace: Radiographic testing can be used to inspect aircraft structures, engines, landing gears, and other components for fatigue, stress corrosion, foreign object damage, and other defects that may affect flight safety and performance.
Power generation: Radiographic testing can be used to inspect nuclear reactors, boilers, turbines, generators, and other components for flaws that may affect the integrity and efficiency of the power plant.
Automotive: Radiographic testing can be used to inspect castings, forgings, welds, and other components for porosity, inclusions, cracks, and other defects that may affect the quality and performance of the vehicle.
Medical: Radiographic testing can be used to inspect implants, prosthetics, medical devices, and other components for defects that may affect the functionality and biocompatibility of the product.
Radiographic testing is a versatile and effective technique for detecting internal defects in various materials and products. It can provide high-resolution images of the test piece without causing any damage or alteration. It can also be used to measure dimensions, thicknesses, shapes, and orientations of the test piece. However, radiographic testing also has some limitations and challenges, such as:
The need for radiation safety measures and regulations to protect the operators and the environment from exposure to harmful radiation.
The difficulty of interpreting radiographic images due to factors such as geometric distortion, image contrast, noise, overlapping features, and human error.
The dependence on the orientation and position of the defect relative to the radiation source and detector for detection and characterization.
The high cost and complexity of equipment and facilities required for radiographic testing.
Therefore, radiographic testing should be performed by qualified and certified personnel who have adequate knowledge and skills in radiation physics, radiographic equipment operation, image processing and evaluation, defect recognition and characterization, and radiation safety. Radiographic testing should also be complemented by other non-destructive testing techniques that can provide additional information or verification of the test results. 061ffe29dd