NDT Inspection of Tensile Strength, Yield Stress, Residual Stress, and Fracture Toughness

Tensile, Yield, Residual Stress, Fracture Toughness | NDT Mechanical Properties Analysis 

LPR’s nondestructive NDT inspection and testing units help insure that materials used in high stress applications meet ever increasing technical standards and regulatory requirements when new and remain stable throughout their service life.

As material ages, mechanical, chemical, and thermal effects cause its dimensions, shape, and internal structure to change. Unchecked, these changes degrade the safety of the material and shorten its useful life. Companies have to assess these changes with either destructive tests or LPR Global’s NDT equipment, which can be used on-site.

LPR Global offer equipment which makes use of Instrumented Indentation Technology (depth indentation). This NDT equipment is ideal for API pipe inspections and inspections related to PHMSA tensile and yield strength properties testing.

Operators can attach strength information to each section of the pipe to determine where and when pipe repairs are required.

Some oil&gas pipes are old enough to not have any records of grades used, IIT method is ideal for material and grade verification as it does not require a need to know pipe grades.

Our nondestructive NDT testing and inspection machines, equipment, and tools assist you in getting accurate data on the soundness of all materials. With automated operation and reporting users can acquire an accurate evaluation of all material property changes over time, to ensure that your plant, equipment, and everything you produce will run safely and economically for the expected design life.

Comparison of IIT Method Results with Destructive Tensile Tests

Measuring stress strain points using the depth-load indentation method at 15 points, IIT equipment allows to build a stress strain curve which is used to obtain yield stress and tensile strength.

In-field accuracy of results when compared to the destructive tests is less than 10% deviation. Normally, 3%-5% deviation is standard for the IIT method.

NDT testing and inspection equipment provides flexibility to gather accurate, timely material data to lessen the likelihood of sudden, expensive, and potentially disastrous material failures.

Instrumented Microindentation Study on Long-term Aged Materials

AIS series nondestructive NDT testing and inspection equipment offer many advantages over competitive material analysis system offerings. Our nondestructive NDT testing and inspection machine offer functionality and custom software that are field upgradeable; so setup is easy and convenient. Testing methods and analytical results comply with ISO standards.

NDT Equipment for Nuclear and Power Plant Applications

Our state-of-the-art nondestructive NDT inspection and testing machines are compact, portable, operate in-field, and easy to use.

Our NDT inspection and testing machines provide information on material properties such as tensile strength, metal hardness, elasticity, transformation, fracture toughness, and residual stress. Specimens remain in place during testing and are undamaged at test completion.

Unlike conventional mechanical testing (which destroys the test sample), the AIS nondestructive inspection and testing machines leave only a tiny depth sensing indentation mark; the material’s properties and operating characteristics are unchanged.

Gas Mega Rule | Mega Rule Material Verification Technology

Currently, all pipelines constructed before 1970 are required to have TVC (Traceable, Verifiable and Complete) records of material tensile strength and yield stress. Interstate and intrastate pipeline owners are required to update incomplete records as far back as 1940s.

With a possibility to collect real-time information for previously non-regulated pipelines, operators of equipment will be able to assess and rank risks, improve pipeline safety, and gather information required for the regulatory inspections, including Gas Major Pipeline Safety Rule.

Such assessments involve increased reporting and safety as per 192.607 for traceability and material verification technology through non-destructive technologies.

In a recent report prepared by the Gas Technology Institute (GTI) named “Validating Non-Destructive Tools for Surface to Bulk Correlations of Yield Strength, Toughness, and Chemistry” accuracy and effectiveness of Frontics AIS indentation technology are evaluated and tested. In this research, GTI’s optimum causal models combined with the Frontics AIS technology data achieved a 95% confidence level in ultimate tensile strength and yield strength predictions by overlapping yield and ultimate tensile strength from lab tests across the entire pipe sample DOE on non-seamless pipes, including pipes with long seam welds like ERW and SAW.

Frontics’ equipment is recognized as an accurate, efficient, and cost-effective tool for material property confirmations of service pipelines to meet the new DOT/PHMSA regulations that require operators to backfill their material property records for older pipeline segments.

GTI’s Report Conclusions

Frontics AIS Non-destructive NDT Testing and Inspection Equipment Benefits

The AIS Nondestructive NDT Testing and Inspection Equipment series is:

Compared with expensive and disruptive destructive testing methods, our AIS series nondestructive NDT equipment and portable NDT tools generate accurate test results that meet ISO and KEPIC standards.

We offer six nondestructive NDT inspection and testing unit models, including the AIS3000 (residual stress, tensile strength testing), the AIS2100 (tensile strength testing), AIS3000 Compact (tensile stress and residual stress testing).

Tensile Strength, Yield Stress NDT Inspection | AIS2100 NDT 

Testing for tensile properties can now be done accurately and non-destructively with the AIS2100. This nondestructive NDT inspection and testing unit is easy to transport and use in the field, obtaining precise load and depth data continuously with real time reporting.

Each test takes less than 3 minutes to perform per point. Each inspected area is recommended to be tested for 3-5 indentation points. On average, it takes 2-3 hours to perform a test on one API pipe and 5 various locations. Test results are generated instantly.

In-field AIS2100 series generates an indentation load depth curve used to show tensile properties such as flow curve, yield strength, tensile strength, and work hardening exponent.

The AIS2100 nondestructive NDT inspection and testing machine has a high power motor and high-strength decelerator and precisely controls moving parts and speed. It comes with multiple indenters for Rockwell A/C/D and Vickers hardness measurement.

This complete nondestructive NDT inspection machine package includes mounting hardware for various test sites including: mechanical chain, u-block, v-block, and flat and curved magnets. All indentation components and custom software for analysis and reporting are also provided.

The advantages of the AIS2100 nondestructive NDT Inspection Machine include: