Nondestructive Testing

Non-destructive testing in the steel industry of material with ultrasonic non-destructive tests have more than 40 years old. From the earliest times, with oscillations of ultrasound for detection of defects in different materials, it has become a classic test on the basis of measurements method taking into account all the factors that influence. Today expected that tests of ultrasound, supported by great advances in the technology of instruments, can give reproducible results test inside margins reduciso. This assumes exact knowledge of the factors that influence and the ability to apply these in the tests. Not all influences have to be seriously considered by the operator. In many cases, some of the influences can despise without exceeding the limits of tolerance that the measurement allows, which simplifies the test sequence and reduces test time. In the early 1950s, the technician only knew radiography (x-rays or radioactive isotopes) as a method for the detection of internal defects, as well as the methods of non-destructive testing of the surfaces of materials, e.g., Dye penetrant and magnetic particles. Even more, Yy was developed after World War II, the method of ultrasound, as described by Sokolovin 1935 and applied by Firestonein 1940, various instruments were soon available for ultrasonic testing of materials.

The principle of ultrasound is based on the fact that solid materials are good conductors of sound waves. By the fact that the waves are not only reflected, on surfaces, but also by internal flaws (separation of material, inclusions, etc.) the effect of the interaction of the waves of sound with the material is stronger the smaller wavelength. This means that waves of ultrasound should be used in a range of frequencies between 0.5 MHz and 25 MHz and that the resulting wavelength is in mm. With lower frequencies, the effect of the interaction of the waves with internal failures would be so small that detection becomes questionable. Both methods of testing, x-rays and ultrasound tests, methods are most commonly used tests of different parts of internal fail-safe.

This means that today’s tests are possible with the method most economical test and not risk ultrasonic; on the other hand special test problems are solved, as before, with the x-ray. In cases that require the highest security requirements (e.g., nuclear power, aerospace plants), you can use both methods. Ultrasonic (UT) can identify changes in bearings, gears, and the rotating machinery due to changes in load or wear. Other methods of ultrasonic inspection as the pulse-echo technique can detect faults and estimate the size comparison of the amplitude of an echo reflected from an interface with an interface of known size reference. The gauges are often calibrated with samples of a known thickness, density or mass. Felipe Garcia is a consultant of Ibertest international tests of Material and steel source: press release sent by ibertestint.