ULTRASONIC TESTING is one of the non-destructive tests (ultrasonic test) in the inspection of all kinds of parts, especially the welding test of welded parts, and high-frequency sound waves are guided in the tested part and reveal surface and sub-surface defects. Sound waves pass through the material with some energy attenuation and are reflected when hitting the boundary of two different materials. The return wave is received and analyzed to detect the location and type of fault. This method is also known as the ultrasonic test.

Ultrasonic waves are often completely reflected at the metal-gas boundary. At the metal-liquid or metal-solid boundary, incomplete reflection occurs, and due to the difference in some properties of the material, a certain percentage of energy is reflected.

Cracks, laminations, shrinkage defects, cavities, bursts, flakes, pores, bonding faults And other discontinuities that can behave like a metal-gas boundary are easily recognized. Also, impurities and other cases caused by the non-uniformity of the metals under test, due to the presence of some reflection, the dispersion of ultrasonic waves or the production of some other types of ultrasonic waves can be detected.

Most ultrasonic devices detect and show defects by one of the following:

Energy reflection from the metal-gas boundary, metal-liquid boundary or other discontinuities within the metal.
The passage time of sound waves inside the piece from the point of entry into the material in the transmitter probe to the point of exit from the material to the receiver probe.
Attenuation of sound waves in the form of absorption and dispersion inside the piece

Ultrasonic testing or inspection is used for material testing and quality control in all major industries, which includes ultrasonic testing of casting, rolling, forging, welding joints, electrical and electronic components, production and manufacturing of steel, aluminum, titanium, construction of structures, Such as pressure tanks, ships, bridges, vehicles, machines, jet engines.

In-service ultrasonic testing is used for preventive maintenance to detect imminent failure of railway rails, pressure columns, rotating shafts, mining equipment and other machinery.

Defects shown include cracks, laminations, shrinkage, cavities, bursts, flakes, pores, continuity. It is incomplete (bonding faults). Defects may be inherent in raw materials caused by production and heat treatment. Or it may be due to fatigue during service, corrosion or other factors. Ultrasonic testing is also used to measure the thickness of metal sections.

Limitations:

Finding the defects of the manual ultrasonic brush requires the precision and skill of the operator
A lot of technical knowledge is needed to prepare ultrasonic test instructions
Rough and uneven parts, very small and thin or dissimilar parts can hardly be tested.
Small discontinuities that are too close to the surface may not be detected.
In order to effectively pass the energy of ultrasonic waves between the probe and the probe, a coupling material is needed
A reference standard is needed to calibrate the device and determine the type of defect
Advantages of using 3T company’s ultrasonic services:

The presence of an experienced team of ultrasonic experts
ASNT NDT Level II certified skilled inspectors and trained in the company’s training academy under the personnel training guidelines according to the level two ultrasonic training headings.
Preparation and approval of test instructions by the best LEVEL III experts and advice on the implementation of instructions.
Using modern equipment made by the best companies in the world.
Use of equipment suitable for ambient temperature, type of parts, desired sensitivity and work speed.
High skill in inspecting T-K-Y joints and special parts.