The methods and qualification standards for non-destructive testing of mechanical valve castings
One, Introduction
Mechanical valve castings are common components in the industrial field, and their quality directly affects the performance and reliability of the entire equipment. The detection of the internal structure, defects, and surface quality of castings is the key to ensuring their quality. This article will introduce in detail the non-destructive testing methods and qualification standards of mechanical valve castings to provide a reference for the quality control of castings.
Two, Methods of Non-destructive Testing
Radiographic Testing: Radiographic testing is a method that uses radiation to penetrate the material, causing the radiation to be absorbed by the internal defects of the material, thereby forming an image to judge the internal defects of the material. For internal defects such as cracks, gas holes, and inclusions in castings, radiographic testing has a high detection effect.
Ultrasonic Testing: Ultrasonic testing is a method that uses the propagation characteristics of ultrasound in the material, by detecting the reflection and refraction phenomena of ultrasound within the material, to judge the internal defects of the material. Ultrasonic testing can detect internal defects such as cracks and inclusions in castings.
Magnetic Particle Testing: Magnetic particle testing is a method that uses the distribution characteristics of the magnetic field within the material, by detecting the influence of internal defects on the magnetic field, to judge the internal defects of the material. Magnetic particle testing can detect surface defects such as cracks and inclusions in castings.
Penetrant Testing: Penetrant testing is a method that uses the penetration characteristics of penetrant on the surface of the material, by detecting the residue of penetrant within the material, to judge the internal defects of the material. Penetrant testing can detect surface defects such as cracks and inclusions in castings.
Eddy Current Testing: Eddy current testing is a method that uses the distribution characteristics of eddy currents within the material, by detecting the distribution of eddy currents within the material, to judge the internal defects of the material. Eddy current testing can detect surface defects such as cracks and inclusions in castings.
Three, Qualification Standards
The qualification standards for non-destructive testing of castings usually include the following points:
For internal defects such as cracks, gas holes, and inclusions, their sizes, depths, and quantities should comply with relevant standards.
For defects such as surface cracks and inclusions, their sizes, depths, and quantities should comply with relevant standards.
For surface defects such as sand holes, gas holes, inclusions, etc., their positions, quantities, and sizes should comply with relevant standards.
The dimensions, shapes, and surface roughness of castings should comply with relevant standards.
The hardness, strength, toughness, and other properties of castings should comply with relevant standards.
Four, Conclusion
The non-destructive testing of mechanical valve castings is the key to ensuring their quality, and the setting of their qualification standards should also comply with relevant regulations. Therefore, for the non-destructive testing of mechanical valve castings, it should strictly follow relevant standards to ensure their quality. At the same time, defects found during the testing process should be repaired in a timely manner to ensure the quality of the mechanical valve castings.