Non-destructive testing utilizes the acoustic, optical, magnetic, and electrical properties of materials to detect defects or inhomogeneities in the inspected object without damaging or affecting its performance. It provides information such as the size, location, nature, and quantity of defects. Compared to destructive testing (DDT), NDT has the following characteristics:
First, it is non-destructive because it does not impair the performance of the inspected object. Second, it is comprehensive because, being non-destructive, it allows for 100% comprehensive testing when necessary, which is impossible with DDT. Third, it covers the entire process. Destructive testing is generally only suitable for testing raw materials, such as the tensile, compression, and bending tests commonly used in mechanical engineering. These destructive tests are performed on manufacturing raw materials.
For finished products and in-use items, destructive testing cannot be performed unless they are no longer intended for use. NDT, however, does not damage the performance of the inspected object. Therefore, it can be used for testing not only manufacturing raw materials, but also intermediate processes and the final product, and even for equipment in service. Non-destructive testing (NDT) visual inspection scope:
1. Weld surface defect inspection: Inspect welds for surface cracks, incomplete penetration, and weld leaks to assess welding quality.
2. Condition inspection: Inspect surface defects such as cracks, peeling, striations, scratches, pits, protrusions, spots, and corrosion.
3. Internal cavity inspection: After certain products (such as worm gear pumps and engines) have been in operation, perform endoscopic inspections according to the items specified in the technical requirements.
4. Assembly inspection: When required, use a 3D industrial video endoscope to inspect assembly quality; after assembly or a certain process is completed, check whether the assembly positions of each component meet the requirements of the drawings or technical conditions; check for any assembly defects.
5. Foreign matter inspection: Inspect for residual internal debris, foreign objects, and other foreign matter within the product's internal cavities.