What problems hidden inside large cast steel parts can be discovered by non-destructive testing?

2024-08-14 13:48:10

Large cast steel parts are widely used in mechanical, manufacturing, and other fields due to their large volume and complex structure. Ensuring internal quality is crucial during production and use, as any minor defects may lead to accidents. Therefore, it has become particularly important to use non-destructive testing technology to detect internal defects in these steel castings.

Non destructive testing is a technical means of detecting internal defects without damaging the tested object, which includes various techniques such as radiographic testing, ultrasonic testing, magnetic particle testing, and penetrant testing.

1. Common internal defects are pores and sand holes, which are formed by gas and solid inclusions during the casting process. These issues can be inspected through radiographic testing of large cast steel parts because radiographic images can clearly display the location and size of internal voids and inclusions.

2. Cracks are products of stress concentration, which may be formed due to improper casting, uneven internal stress, or improper subsequent cold and hot treatment. Ultrasonic testing can identify the presence of cracks through reflected waveforms and accurately determine the depth and direction of cracks.

3. Leakage defects may cause tiny channels for liquid or gas to leak through castings. Penetrant testing and magnetic particle testing are better at detecting micro cracks and other leakage defects on or near the surface, utilizing the permeability of liquids and changes in magnetic fields.

Overall, non-destructive testing can timely detect and evaluate internal problems in large cast steel parts without affecting their performance, improving quality and reducing costs.