Ultrasound : Ultrasonic testing is a non-destructive testing method for detecting indications and defects within a material. Ultrasonic testing is based on ultrasonic wave transmission and reflection inside a material. The method uses a device similar to an oscilloscope, a probe, as well as a couplant. The probe is applied to the surface of the part to be inspected, via a coupling to facilitate the transmission of ultrasound. The probe is connected to the device that generates a signal to the probe. The transmitted wave travels through the material until it encounters an indication, or another interface with the air, and then returns. The distance, the travel time and the speed give information as to the location and dimensions of the indications.

Radiography : Radiography is a non-destructive testing method for inspecting the presence of indications and defects with a volume, inside a material. The method uses a radioactive source, as well as an X-ray film (or a photosensitive surface). The source is oriented towards the part to be inspected and the film is applied to the opposite surface. The method makes it possible to obtain an image of the density of matter of an object traversed by X or gamma radiation. After exposure, the film is developed. Depending on the thickness of the part and the density of the material, including the presence of indications and defects in volume, the film will show a contrast, which allows in particular to visualize the state in volume on a two-dimensional image. In general, the denser material will be white, and the less dense parts will be black or dark

Paint : The paint is a coating applied in one or more layers (thin layers of a few tens of micrometers thick, μm), on different materials. The result is obtained only after application and drying. By drying, or prefabricated industrially, the paint forms a solid film, adherent and durable against corrosion.

Metallization: : Zinc metallization is a method of protecting steel by hot zinc spraying. The substrate must be adequately prepared (attachment profile) by abrasive blasting to obtain a durable adhesion of zinc and thus form a protective coating.

Galvanization :   Hot-dip galvanizing is the process of dipping a steel piece into a bath of molten zinc. This is a metallurgical industry technique that is used to sustainably protect a piece of steel from corrosion with zinc. This process gives the protective coating adhesion, impermeability and mechanical strength. A part treated by galvanizing is called galvanized.

Undercut : welding defect where a depression of the base metal is observed in the axis of the weld, at the connection of the weld.

Coalescence : The state of cracks that meet to form only one larger one.

Burn-through : A welding defect observed at the weld root showing that the molten metal has collapsed and may have solidified in large excess from the joint surface to the root. The weld profile observed at the root is irregular and the overthickness at the root is excessive.

Hardness (and microhardness) : a measurement of the surface property of a material. There are correlations between hardness and strength of steels. The hardness test is relatively inexpensive and easy to perform in general. The hardness test method uses the penetration of a punch, for example a diamond tip (Rockwell hardness), a hardened steel ball (Brinell hardness) or a diamond pyramid (Vickers hardness).

Fatigue : The process of material damage, which generates and propagates cracks in a cyclic loading mode, usually over a relatively long period. The main stages of fatigue are crack initiation (if defects are not already present in the material), crack propagation and final failure.

Indication : the result of observing a discontinuity obtained by means of a nondestructive test, with the naked eye or with the aid of a device. An indication requires interpretation by a qualified qualified inspector for the method used.

Lack of fusion: welding defect where it is observed that the base metal has not melted to the surfaces to be welded, or that the molten metal has not played its role of melting and dilution enough of the base metal to welded.

Filler metal : metal coming from an electrode during welding. The filler metal and some of the molten base metal create the melted zone, the weld itself.

Scanning Electron Microscope (SEM): : Microscope used for laboratory observation at very high magnifications. It also has the advantage of having a large depth of field, which allows to observe reliefs such as for example the surfaces of cracks or broken parts.

Bearing : this is a component used in mechanical engineering to support and guide, in rotation, driveshafts.

Corrosion pitting : area corroded very locally (cavity) on a macroscopic or microscopic scale, and can go deep leaving the adjacent surface relatively intact or less corroded. Chlorides (salts) accelerate the formation of pits in general on metals. A surface attacked by this type of corrosion may include a significant number of pitting corrosion.

Heat Affected Zone (HAZ):  Areas that are adjacent to the weld zone of a weld, which is the base metal that has been altered by heat during welding. In general, this zone has weakened properties, mechanically and chemically. The microstructure has changed at this point, without melting during welding.