Non destructive testing

The Non destructive testing are a series of diagnostic methods able to determine faults in materials, machine components, welded structures, and projects during study or test phases, etc.;

Non destructive testing are defined as such inasmuch as they permit assessing the faults or structural characteristics of materials without altering their physical state or geometry.

The various methods used in non destructive testing are often complementary. Consequently, in order to choose test procedures, various factors have to be considered:

1. PHYSICAL PROPERTIES: Ferromagnetism, electric conductivity, sound conductivity, X-ray opacity, material porosity.
2. STATE OF MATERIAL: Rolled, forged, welded, extruded, etc.
3. FAULT FINDING: Type, position, entity, etc.
4. GEOMETRY: Shape and dimensions, degree of surface finish, etc.

STC performs non-destructive tests in company facilities or in its own laboratory.

A method for finding surface faults inside parts. This is a visual inspection.
APPLICATION: Wherever access exists to the inside of the part to be checked e.g., welded pipes, corrosion inside lines or tanks, etc.
CONTROLLABLE PRODUCTS: Motors/Engines, fluid pipes, tanks, hidden compartments, etc.
BENEFITS: Permits remote visual inspection without removing parts to be checked.
DRAWBACKS: Impossible to use without direct access to the inspection area or in the case of special geometries

Method for finding anomalous heat differences.
APPLICATION: Wherever a heat difference exists pointing to a possible fault, e.g., plant engineering, chemical, electrical, building sectors, etc.
CONTROLLABLE PRODUCTS: Overheating of electric motors, power contacts, ovens and boilers, heat exchangers, humidity surveys, etc.
BENEFITS: Permits remote infra-red visual inspection, seeing what our eyes cannot see.
DRAWBACKS: Impossible to use in certain conditions.

Method used to find material defects and for Thickness Gauging.
APPLICATION: on all materials (metal and non-metal), able to propagate ultrasonic waves with frequencies between 16 KHz and 20 MHz. (Cast-iron, carbon steels, stainless steels, aluminium and light alloys, composite materials, concrete, ceramics, plastics, wood, etc.).
CONTROLLABLE PRODUCTS: Rolled, forged, drawn, castings, platings, weldings, pipes, etc.
BENEFITS: Possibility of establishing depth and position of faults inside materials, thickness measuring.
DRAWBACKS: Impossible to use on: high sound-dampening materials, special geometries.

A method used to discover surface faults
APPLICATION: on all non-absorbing or porous materials. (Cast-iron, carbon steels, stainless steels, aluminium and light alloys, composite materials, ceramics, etc.)
CONTROLLABLE PRODUCTS: Rolled, forged, drawn, castings, platings, weldings, pipes, etc.
BENEFITS: Possibility of use on non-ferromagnetic materials.
DRAWBACKS: Impossible to use on: porous materials and painted materials. Good cleaning is required.

Method used to find surface or sub-surface faults.
APPLICATION: on all ferromagnetic materials. (Cast-iron, carbon steel, etc.)
CONTROLLABLE PRODUCTS: Rolled, forged, drawn, castings, weldings, pipes, machine-worked products, etc.
BENEFITS: The perfect cleaning of the pieces to be inspected is not required.
DRAWBACKS: Can only be used on ferromagnetic materials.

Method used to find internal material faults
APPLICATION: on all materials, Cast iron, carbon steels, stainless steels, aluminium and light alloys, composite materials, ceramics, plastics etc.
CONTROLLABLE PRODUCTS: Welded joints, rolled, forged, drawn, castings, pipes, machine worked pieces.
BENEFITS: Permits finding internal and external faults in the controlled material.
DRAWBACKS: Impossible to use on radiation opaque materials or those with special geometries.

Method used to check the composition of metal alloys directly outside the laboratory.
APPLICATION: on all metals, titanium, carbon steels, stainless steels, aluminium and light alloys, bronzes, copper and its alloys, etc.
CONTROLLABLE PRODUCTS: Welded joints, rolled, forged, drawn, castings, pipes, machine-worked products, etc.
BENEFITS: Permits finding controlled-material nonconformities according to the specific chemical characteristics of each alloy.
DRAWBACKS: Impossible to use on materials with surface treatments which do not permit contact with the material.

Method used to find “through-and-through” defects in gas and liquid sealed containers.
APPLICATION: on all materials, Cast iron, carbon steels, stainless steels, aluminium and light alloys, composite materials, ceramics, plastics, etc.
CONTROLLABLE PRODUCTS: Welded joints, tank plates, corroded plates, pipes, sealed surfaces, etc.
BENEFITS: Permits finding “through-and-through” defects in the controlled material.
DRAWBACKS: Impossible to use on breathable materials.

Method used to measure the hardness of materials and metal alloys.
APPLICATION: on all materials, Cast iron, carbon steels, stainless steels, aluminium and light alloys, ceramics, plastics, etc.
CONTROLLABLE PRODUCTS: Welded joints, plates, pipes, machine-worked products, etc.
BENEFITS: Permits testing the hardness of materials after any treatments performed to assess conformity.
DRAWBACKS: depending on piece geometry and impossible to fit appropriate probes.