Automated Ball Indentation

What ABI is

Automated Ball Indentation (ABI) is a proven technology that makes the non-destructive measurement of yield strength and ultimate tensile strength of all metals (and fracture toughness on ferritic steels) possible. The method was developed by Fahmy Haggag at Oak Ridge National Laboratory for use in the nuclear industry, and it derives mechanical properties directly from a controlled indentation rather than from a machined tensile specimen.

Testing without taking parts out of service

Because ABI does not require cutting or removing material, facilities can keep operating while testing is underway. On a pipeline, for example, ABI allows the line to continue its normal operation while it is being analyzed.

What it measures

From a single indentation sequence, ABI determines a range of mechanical characteristics without cutting samples, including:

• Yield strength
• Ultimate tensile strength
• Strain-hardening exponent and strength coefficient
• True plastic stress-strain curves
• Uniform ductility
• Maximum allowable operating pressure
• Fracture toughness on ferritic steels

Where it's used

ABI has been deployed successfully on oil and gas pipelines, pressure vessels, automotive frames, airplane parts, forgings, coke drums, and offshore platforms to determine mechanical properties where documentation is missing or testing was never performed.

Reaching what conventional testing can't

ABI can also measure properties that are difficult or impossible to obtain by conventional methods, such as yield strength on small objects, properties within weld heat-affected zones, and fracture toughness on thin sheet metals. PMI Specialists operates two of roughly thirty ABI testers in existence worldwide, giving our technician team the experience these projects demand.