NON DESTRUCTIVE TESTING OF WELDS

NON DESTRUCTIVE TESTING OF WELDS

ABSTRACT


         Non-destructive testing, as the name implies, does not damage or reduce the service life of the component. Usually these tests do not directly measure the mechanical properties such as tensile strength or hardness, but they are used to locate the defects of flaws in the component. These flaws may reduce the useful life of the component resulting in the premature failure even with a sound design and proper selection of materials. To obtain a high level of reliability, the defects should be absent or should be at a minimum level. Also, the component should be periodically tested for the defects during the service. As soon as the defect size exceeds that allowed in the design, the component should be replaced before its premature failure to avoid dangerous results.
        Various methods are used to detect defects in component. The most common types of non destructive tests are given below:
1.    Visual Inspection
2.    Liquid Penetration
3.    Magnetic Particle Inspection
4.    Ultrasonic Inspection
5.    Radiograpgy (X-ray and Gamma ray) Inspection.