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Non-destructive testing (NDT) has been established as a standard for flaw detection in many industries. With the ability to inspect welds and other structures—material surface, subsurface, or volumetric—for discontinuities or damages, industries like aerospace, automotive, oil and gas, and manufacturing have been able to ensure the safety of the products and operations. Many inspection methods have been utilized, and various instruments and probes have been developed to achieve the best inspection result. However, the use of intuitive NDT imaging software is equally as important. With the software’s clear image capture and display ability, technicians can quickly and easily interpret the result to identify the best possible solution.  

NDT Imaging Software for Accuracy in Flaw Detection

Eddy current testing (ECT), ultrasonic testing (UT), or any other NDT method, can truly be effective when the data captured is interpreted with accuracy. NDT imaging software allows the data captured during the inspection process to be analyzed and digitized in real-time or for offline interpretation. The software can also be used to facilitate easy integration with other NDT products to effectively scan the component and display signals for potential flaw detection. 

Having a clear and easy-to-use NDT imaging software allows technicians to easily understand and set up the inspection system. The captured data can then be processed and the output analyzed regardless of the technician’s skill level. The functionalities of NDT imaging software provide the following benefits:

Accurate Flaw Identification: NDT imaging software can allow the comprehensive display of acquired data in a 2D or 3D format. Analysts can accurately analyze the acquired A, B, or C-scan imaging for in-depth identification of flaws including cracks, corrosion, inclusion, or other discontinuities. 

Workflow Optimization: The software allows for easy planning, scheduling, data acquisition, and analysis capabilities facilitating an efficient inspection process. Some software also provide auto data acquisition and analysis, allowing technicians to focus on other more important tasks, thus, improving productivity.   

Faster Inspection: With each inspection and optimized workflow, data can be collected at a much faster rate. Data analysis parameters can be set up upfront. The output can also be received in a relatively faster time. This function can help minimize downtime and improve productivity and component reliability.  

NDT Imaging Software Features

Output may vary depending upon the various features of the NDT imaging software. Here are some features that industries look for to determine inspection and analysis suitability. 

• Data Merging: In some inspection processes, data capture may not be possible with a single scan. In such a case, software such as UltraVision with the ability to merge multiple C-scans into a single file can be a useful feature. Each individual scan can be stitched and manipulated to ensure proper alignment and display in a single interface. This ability helps in accurate detection and determining the size of a flaw.
• 3D Data Analysis: Software such as UltraVision provide a 3D module where all the data and scans can be acquired and presented in a 3D environment for all simple and complex geometrical components. The visual analysis of the surface condition in a simulated environment facilitates improved flaw detection accuracy.
• Historical Data Comparison: This capability allows users to compare current and previous inspection data over time. Any changes in the signals can be easily analyzed to identify any new or growing flaw formations. 
• Online or Offline Data Analysis: Depending upon the application, industries may seek online or offline inspection and analysis ability. This increased computing and data processing ability has enabled advanced software to perform real-time data analysis for critical inspection tasks without compromising image display resolution.  

Leveraging Software Capabilities for Improved Inspection

With new and improved capabilities, NDT imaging software is becoming more user-friendly. It is now possible to automate elements of the data acquisition process, analyze data in real-time, and visualize data in a 3D environment, without compromising the quality of the output. Industries can leverage these benefits of NDT imaging software to acquire advanced flaw detection ability while improving their productivity and cost-efficiency.

Zetec offers a wide range of NDT imaging software solutions for industrial UT and ECT inspection requirements. For more information on our NDT software and instrumentation, contact us today.

Non-destructive testing (NDT) instrumentation was developed in the early 1900s. Since then, NDT technology has formed the basis for modern flaw detection across many industries. Rapid advances in technology have allowed NDT methods to be tailored to fit specific industrial inspection requirements. For ultrasonic testing (UT), this advancement has come in recent years as a powerful data acquisition and imaging technology.

A traditional ultrasonic inspection method utilizes high-frequency ultrasonic waves to transmit through a single transducer onto the material for the purpose of flaw detection. The process is extremely effective when it comes to the identification of corrosion, cracks, pitting, and other types of flaws. Additionally, the ability of UT to be utilized with a wide range of materials makes it the foremost NDT choice for a wide range of industries. Different methods of UT can have a major impact on safety, productivity, and quality control in a wide range of industrial applications as discussed further.

Learn more about ultrasonic testing.

Advanced Ultrasonic Inspection Techniques

In industries like aerospace, automotive, manufacturing, and petroleum, ultrasonic inspection has been trusted for its reliability in flaw identification. The advanced UT probes and instruments are suitable for inspecting complex geometries such as bends and curves, providing volumetric coverage and consistent results with ease. The ability to scan both metallic and non-metallic structures also makes ultrasonic inspection techniques one of the most flexible options compared to other NDT methods. The flexibility, excellent data processing capabilities, and greater inspection speed of UT equipment facilitate industries to leverage greater value for the initial investment.

Learn more about ultrasonic testing equipment.

To further increase the value of the UT inspection method by ensuring greater precision, coverage, and productivity, many ultrasonic inspection techniques have been explored.

Phased array ultrasonic testing (PAUT) uses a series of several transducers on a single assembly that can be pulsed independently at different times to transmit and receive ultrasonic signals. The transducers can be pulsed at different times and the same mechanism can be utilized to optimize the focus and angle of the beam. This allows for the inspection of the material at different angles and focal points for flaw detection. This ability is beneficial in the inspection of complex geometries and varying material thickness for the identification of corrosion or erosion in a wide range of industrial applications. The use of multiple transducers also enables faster inspection, saving time and increasing productivity in the inspection.

Learn more about phased array ultrasonic testing.

Time-of-flight diffraction (TOFD) is a highly reliable ultrasonic inspection technique that is predominantly used in weld inspections. As the name suggests, the technique uses diffraction for inspection purposes. The transmitter and receiver are placed on either side of the weld. As the ultrasonic beam is emitted from the transmitter, the irregularities present in the material or weld diffract the beam. The receiver on the other end collects the signal and analyses the response time of the beam to travel from the transmitter to the receiver. This technique has been successful in locating flaws and determining their size. Most technicians use this technique alongside PAUT for accurate flaw identification, mostly to get a detailed picture in applications like the inspection of pipeline welds.

Learn more about the time-of-flight diffraction technique.

PAUT inspection is further enhanced by its advanced data acquisition methods such as full matrix capture (FMC). The multiple transducers used in PAUT can sometimes lead to raw signals being neglected in the analysis. FMC captures the A-scan—raw time-domain signals—from every possible transmitter-receiver combination, and analyzes them in real-time, or stores them for processing later. These signals, organized as a matrix grid, act as pixels in the image. For manufacturing, petroleum, or other industries, this data capture technique facilitates the characterization of flaws including corrosion, cracks, inclusion, and porosity.

Learn more about full matrix capture.

As discussed above, FMC captures the time domain signals and organizes them in the form of a matrix grid. This is made possible by using an advanced focusing algorithm, namely, the total focusing method (TFM). TFM computes the signals for every possible depth, angle, and focus, and arranges them in an array to generate a 2D or 3D image for in-depth detailing of the flaw present in the material for real-time or offline interpretation. Technicians can easily interpret the flaw and take informed precautionary measures to ensure the safety and productivity of the operation.

Learn more about the total focusing method.

Leveraging UT Testing for Various Industries and Applications

UT inspection has been an integral part of many critical infrastructural projects. In the petroleum sector, the effectiveness of UT can be seen during inspection of pipes, storage tanks, especially, welds and bolts for their strengths and effectiveness. The pre- and post-installation inspection ability of UT allows technicians to maintain safety and ensure component integrity through fast scanning and analysis for simple and complex geometries.

Learn more about UT testing for oil and gas.

In addition to the inspection of metallic pipes and components, PAUT with TOFD is equally capable of advanced flaw identification in high-density polyethylene (HDPE) piping. HDPE is used for its strength, corrosion resistivity, and service life. HDPE pipes can be prone to flaws such as lack of fusion, porosity, and inclusions, just like their carbon steel parts. The benefits of PAUT with TOFD can be leveraged to easily identify irregularities and detail the extent and positioning of flaws.

Learn more about TOFD inspection of HDPE piping for petrochemical use.

In the aerospace and automotive industry, UT inspection can be a part of effectively testing composite materials that these industries are increasingly adopting. Ultrasonic testing techniques such as PAUT can effectively examine components such as rods, tubes, or plates made of composite materials with excellent accuracy and without any resistance.

Learn more about composite inspection techniques.

Advanced UT Inspection Solutions

The innovation and advancement in ultrasonic inspection techniques have made it a primary choice for NDT inspection in many industries. With advanced UT solutions, it is now much easier for industries to meet a wide range of inspection needs to ensure safe operation through flexible scanning, high-resolution imaging, and precision in testing.

Learn more about advanced UT testing equipment and software solutions.

Zetec has been a leading provider of ultrasonic testing equipment and solutions for decades. To learn more about using ultrasonic technology in your industry, contact Zetec today.

Major and minor infrastructures, tools, machinery, and equipment in almost every industry make use of fasteners for the purpose of holding components together and increasing their ultimate strength. While vital, fasteners are often overlooked during non-destructive testing (NDT) of these components. Without a proper fastener inspection procedure in place, failure may go unnoticed and can have severe consequences resulting in risk to operations, facilities, and in some cases, human lives. To mitigate these risks, a thorough NDT inspection could help identify any damages to the fasteners. 

Many industries use ultrasonic testing (UT) and eddy current testing (ECT) as the primary methods of inspecting fasteners. The intuitive and competent flaw detection capabilities of these methods allow the strength of fasteners and the structural integrity of components to be thoroughly tested. 

The Necessity of Inspecting Fasteners

Fasteners used in industries include nuts, bolts, and other similar types of hardware that can mechanically join the parts together. In manufacturing or infrastructural operations, these fasteners can also be exposed to different types of loads. When exposed to extreme loads, fasteners can be the subject of fatigue failures. There are also various other reasons inducing the potential flaws and failure of the bolts and fasteners, such as:

• Vibration or shock load, especially in vehicles
• Overload and fatigue
• Improper fastener and component material selection
• Thermal expansion or contraction
• Improper torque
• Environmental conditions 

Metallurgical, load, and environmental issues can give rise to a number of flaws in the fasteners. This may include cracking, corrosion, pits, inclusions, or other discontinuities. Realizing the extent of these flaws in the early stage is important to prevent potential damage to the structure or equipment.

With NDT, technicians can establish an ideal fastener inspection procedure to determine the location, size, and overall extent of the flaw before the structure suffers mechanical failure. 

Ensuring Fastener Standards with UT and ECT

Flaws within fasteners can be difficult to visually detect or hidden in the case of in-service fasteners. Thus, for thorough and accurate inspection of fasteners pre- and post-installation, industries use eddy current and ultrasonic testing as their primary NDT method.

Fasteners used in infrastructural projects such as building construction, oil and gas pipeline, or structures such as bridges or tunnels, are exposed to a harsh condition that facilitates flaws. With extensive flaw detection ability, phased array ultrasound testing (PAUT) inspection can help to identify the extent of indications. The high-frequency ultrasonic wave from the UT transducer enables the identification of cracks and discontinuities in difficult-to-inspect areas. Through pre- and post-installation PAUT inspection, it is possible to characterize and size indications through inspection data.

Similarly, with eddy current inspection, it is much easier to identify surface or near-surface cracks and anomalies in a fastener. The electromagnetic field from ECT probes facilitates the easy identification of cracks within complex fastener geometries. 

With advanced NDT instruments with UT and ECT capabilities, technicians can fulfill the goal of:

• Identifying flaws in installed fasteners without removing them from the system 
• Performing high-resolution 2D/3D scans to detect the extent of cracks and corrosion
• Locating flaws in a fastener
• Identifying flaws in difficult-to-reach areas and within complex geometries 
• Detecting major and minor flaws with accuracy

Leveraging NDT for Your Fastener Inspection Procedure

Different industries and applications require different types of fasteners, thus, various UT and ECT probes are available to fulfill the inspection needs. With the right scanners and probes, industries can develop a detailed fastener inspection procedure and be confident in the accuracy of inspection results. With the ability to identify even the tiniest flaws, industries can focus on potential damage prevention, establish routine preventive maintenance, reduce maintenance costs, and ensure operational productivity.

Zetec is a leader in providing eddy current and ultrasonic testing solutions for fastener inspection in a wide range of industries. Contact Zetec today to learn more about our equipment and solutions that suit your inspection needs.     

In industries such as oil and gas, major components like pipelines are laid in rough environments where high-temperature hydrogen attack (HTHA) or stress corrosion cracking can easily develop. These factors can occur often due to the corrosive environment but metallurgical properties within the material can also play a role, creating a weak link in the metal surface or weld surfaces. Inspecting such structures can require an advanced approach such as the total focusing method (TFM) that can perform in-situ analysis and effectively visualize and identify both major and minor flaws in real-time.

By leveraging advanced data processing technology—such as real-time TFM for non-destructive testing (NDT)—industries can reap the benefit of faster, more complete analysis and enhanced productivity. 

The Total Focusing Method Explained

TFM is a commonly used advanced focusing algorithm that utilizes the data captured from full matrix capture (FMC) to create images of an inspected area. This is done by recording the returned signals (A-scan) from multiple directions for every transmitter-receiver combination in the array. The advanced algorithm of TFM processes the raw A-scan signals to generate a frame of pixels. Each individual pixel is then processed using a different set of parameters (such as focal depth or angle) for any dedicated focal law. This resulting TFM frame can then either be stored for further future interpretation or in more advanced instrumentation can be conducted in real-time. The analysis is instrumental in characterizing flaws in a material.

TFM has been successfully utilized in the inspection of different geometries and materials for flaws. But a challenge with the inspection approach has been its inflexibility to perform the inspection and analyze the data on-site. However, new technologies have been developed in recent years with faster data capture and advanced computing capabilities. With the improved processing capabilities, it is now possible to perform analysis in real-time helping industries gain more immediate access to NDT results. For critical applications, real-time analysis assists in enhancing safer operations. 

The Advantages of Real-Time TFM

Immediate access to the inspection data provides many advantages. With real-time capabilities, it is possible to leverage the benefits of TFM for speedy and efficient decision-making to ensure quality and productivity. 

1. Speed: Real-time TFM can offer fast acquisition and processing of the data. The ability to analyze and identify flaws in rough environments on-site or in controlled environments can dramatically reduce the time required for inspection, possibly with no additional external equipment. Without the need to go back to stored data for detecting analysis, operators can make decisions in less time, and effective remedial measures can be implemented immediately, minimizing the risk for sudden failure.   
2. Quality: With TFM, operators can ensure that every minor, difficult-to-detect micro-crack and corrosion is easily detected in real-time with detailed high-resolution imaging and a good signal-to-noise ratio. This makes the interpretation of the data for identifying characteristics of flaws in the inspection area much easier. The capability to identify the type and size of flaws with higher sensitivity in real-time enables immediate preventive action, ensuring quality in service.
3. Productivity: The immediate analysis provided by real-time TFM ensures that there is no unplanned downtime. Thus, industries can ensure that their productivity is maintained or further improved. 

TFM can be immensely cost-effective for industries as it can result in less time spent during analysis, quick resource allocation, less equipment needed, avoidance of downtime, and improvement in productivity.

Leveraging the Capabilities of TFM to Boost Productivity

The advanced data acquisition and high-resolution image processing with TFM are fostered by its increased processing abilities. The same capabilities have made it possible to analyze the high volume of data in real-time. The on the spot analysis supported by real-time TFM helps industries to speed up the inspection process without having to compromise quality and precision, thus boosting productivity.

Zetec is a global leader in nondestructive testing solutions for the critical inspection needs of industries the world counts on every day. Our NDT solutions with advanced TFM algorithms ensure that every minor flaw that can hinder your process is identified in real-time. To learn more, contact Zetec today!

In recent years, phased array ultrasonic testing (PAUT) has changed the industrial take on their non-destructive testing (NDT) approach. It has been successful in providing accurate identification of flaws and discontinuities in the inspection area, pre-or post-service. However, challenges remain when conducting complex inspections like a very thick component. Imaging the characterization of deeper indications can be made easier with the introduction of full matrix capture technology. With this data acquisition method, it is possible to carry out an in-depth inspection of these complex structures. 

Full Matrix Capture and Its Applicability in Flaw Identification

Full matrix capture is a data acquisition for phased array ultrasonics. PAUT eliminates the limitation of single probe ultrasonic testing (UT) by operating with a series of small transducers in a single assembly which can be controlled and swept across a piece to test along the various angles without moving the probes. In doing so, raw signals from individual transducers can be ignored and only a summarized version is captured. Full matrix capture helps in developing a complete picture to identify every possible flaw with detailed data collection. 

Data capture with full matrix capture ensures that every possible data from each transmitter-receiver combination used in the ultrasonic testing is captured. These captured raw time-domain signals (A-scans) can be analyzed in real-time or saved for later processing. These A-scans are digitized and organized into matrix grids which act as a pixel in the image. The processing and reconstruction of the raw data can be done for every possible skew angle, focal point, or aperture, by utilizing advanced focusing algorithms such as the total focusing method (TFM), which can assist in deriving in-depth details from the data. This can include the identification of potential flaws such as cracks, corrosion, inclusions, or porosity. The high-resolution imaging obtained with the full matrix capture data helps in ensuring that even the smallest flaw possible is detected, thus, establishing the strength of the component.     

How Advantages of Full Matrix Capture Support NDT 

The advantage of full matrix capture for non-destructive testing lies in its capability to capture and analyze the data with greater precision. The capabilities of full matrix capture can be leveraged for the following unique advantages:

• A large amount of data can be collected and analyzed in real-time or processed later.
• During the post-processing of data, the beam angles and focus can be readjusted to better characterize the flaw. 
• The range of data captured facilitates inspection for more than one type of flaw without specific targeting.
• The high sensitivity in data capture and high resolution in imaging allows for complete flaw detection in NDT analysis when the proper equipment is used.

Despite these advantages, the data processing phase can be a challenge due to the utilization of a large amount of data. With advanced technology such as Zetec’s TOPAZ 64, the data acquisition and analysis process can be made easier. 

Leveraging the Advantages of Full Matrix Capture for Complete Inspection

Compared to standard PAUT, full matrix capture can provide much more complete data acquisition capabilities, whereby in-depth information can be derived from the inspection area. The real-time or offline data processing capabilities allow technicians to study every single signal in detail in the search for potential flaws. This is a much-needed advantage in ensuring the integrity and strength of a component. The full matrix capture with instruments such as TOPAZ 64 is easier to set up and process thanks to the powerful tools in UltraVision software. The accuracy in inspection can thus be achieved in a fast, precise, and cost-efficient manner. 

Zetec is a global leader in nondestructive testing solutions for the critical inspection needs of industries the world counts on every day. To learn more, contact Zetec today!

Ultrasonic testing has been used in various industries for decades as one of the most efficient flaw detection methodologies. With the emergence of approaches like the total focusing method (TFM), we now have access to more advanced data acquisition and analysis technology that is capable of in-depth flaw characterization. However, conducting analysis using TFM involves a huge data volume to generate high-resolution imaging. This requires significant power for data processing.

Traditionally, the data from an inspection would be recorded for later offline analysis. Advancements in technology have now enabled the ability to process data in real-time which is beneficial in minimizing inspection time and facilitating quick decision making.  

Total Focusing Method for Ultrasonic Analysis

The total focusing method is an advanced focusing algorithm that utilizes the data acquired by the full matrix capture (FMC) technique in ultrasonic testing. It utilizes the beam returns from multiple angles as the input data from the inspection zone. This data can be collected, digitized, and with the right equipment can either be analyzed in real-time or stored for later processing.

The advanced algorithm of TFM ensures that each data, stored in the matrix grid, is thoroughly processed taking into account every possible beam focus. Each frame of the grid acts as an individual pixel constituting the A-scan signal data. The grid is instrumental in the development of high-resolution imagery which helps in clear sizing and characterization of the flaw. This is mostly beneficial for identifying early-stage HTHA flaws (<0.1 mm), stress corrosion cracking, dissimilar metal weld inspection, and other such minor and difficult-to-spot flaws.

However, with an increasing need for efficiency, industries now prefer technologies that can provide faster data acquisition and processing capabilities. The increased processing power of the more advanced instruments has now made it possible to view the matrix grid to perform real-time TFM ultrasonic analysis for immediate interpretation. The data can be processed and analyzed as the scanning is being conducted. The real-time analysis dramatically reduces the time involved for technicians in the identification of potential flaws within the component being inspected. 

Advantages of Real-Time Computing for TFM Ultrasonic Analysis

Advanced ultrasonic testing equipment is available that provides powerful TFM analysis features for efficient computation of the scanned data. This can feature up to 64 active channels and the generation of high-resolution images with up to 1M or higher data points per frame. The option of conducting real-time analysis can help industries in their non-destructive testing (NDT) approach in the following ways:

• Display of detailed images in real-time ensures immediate identification of flaws.
• Faster data acquisition and processing dramatically shorten the time required for inspection.
• The analysis from high-resolution imaging ensures accurate characterization of flaws in the workpiece.
• It is possible to perform TFM ultrasonic analysis of data as the scanning process is being conducted.
• The on-the-spot analysis enables technicians to allocate resources in the case of flaw detection and if any repairs are required, avoiding unplanned downtime. 

TFM Ultrasonic Analysis Solutions

The most significant advantage that TFM ultrasonic testing offers is its capability to effectively acquire data and produce high-resolution images. The concern for system overload and slow down during data acquisition due to the high volume of data can be eliminated by the use of advanced data processing ability provided by high-performance ultrasonic testing equipment with advanced focusing capabilities.

With TFM, it is possible to carry out the volumetric inspection of a complex structure, and in a faster, and cost-effective way. With UT instruments such as Zetec’s TOPAZ 64, data acquisition with TFM can provide highly accurate flaw detection and analysis. 

Zetec is a global leader in nondestructive testing solutions for the critical inspection needs of industries the world counts on every day. Our UT testing equipment with advanced TFM algorithms ensures that every minor flaw that can hinder your process is identified in real-time. To learn more, contact Zetec today!

Welding dissimilar metals allows asset owners to leverage unique properties within each metal to contribute to the final strength and durability of a component. A common example of this is the process of cladding the interior of steel pipes with corrosion-resistant alloys (CRA) which gives the pipe system the strength of steel while adding corrosion resistive properties to it from the CRA to increase its durability. However, as great a solution as it may present, there are many challenges associated with the welding of dissimilar metals, mostly due to the difference in metallurgical properties.

The properties and compositions of metals react differently when subjected to thermal stress. The resulting weld can be susceptible to various kinds of flaws. In ensuring the quality and standards of the weld, non-destructive testing (NDT) plays a crucial role.

Challenges With Dissimilar Metal Welding

The different properties within dissimilar metals often cause problems in the formation of quality fusion. The major problems encountered are differing metallurgical properties, different grain sizes and alignment, and varying acoustic properties, among other characteristics. With these issues on the forefront, the joint resulting from these welds can have the following issues:

• Lack of fusion resulting from the different coefficients of thermal expansion of the weld and base metal
• Inclusions resulting from the different reactions of the metals when exposed to heat depending upon their chemical composition
• Porosity due to the presence of inclusions
• Surface cracking in either layer of the metal during the expansion and contraction resulting from the heat exposure during the weld   

These flaws can severely affect the strength of the final component reducing the value of the need for a dissimilar metal weld in the first place. The issue can be resolved with the use of proper NDT technology which can identify weld flaws before the components are placed in service. With early flaw detection, it is possible to identify the best remedy and ensure weld standards are met.   

NDT Solutions Ensure Dissimilar Metal Weld Quality

Dissimilar metal welds are mostly used in oil and gas and nuclear industries where the integrity of the structural component is crucial. Inspection of the dissimilar metal weld is thus important for such industries in ensuring quality, productivity, and safe operation. Ultrasonic testing (UT) has been used for the inspection of such welds to identify potential flaws.

The propagation of ultrasonic waves to such welded surfaces can be used to identify flaws such as cracks, corrosion, pores, and inclusions through examination of the reflected pulse. Phased array ultrasonic testing (PAUT) further provides the ability to focus the beams. The data and high-resolution image obtained can be identified and analyzed to ensure the location and sizing of the flaw. Yet these types of flaws can be hard to identify or detect, even with phased array UT.

Advanced phased array UT instruments, dual (2D) matrix array probes, along with powerful and intuitive software can play a crucial role in flaw detection confidence. This can ultimately help with uptime, code compliance, and safety.

NDT Inspection Verifies Weld Specification for Industries

Industries like petroleum and nuclear demand high-quality components to ensure the safety and criticality of their applications. The many challenges related to dissimilar metal welds can create conflict for such industries to maintain their standard. Through NDT inspection, it is easier to ensure that dissimilar metal welds meet their specification. The ability to identify flaws, pre-service, provides industries the opportunity to carry out repairs or adopt other options in favor of operational safety. With NDT, the setup and operation of components can become more efficient, safer, and economical. 

Zetec is a global leader in non-destructive testing (NDT) solutions for the critical inspection needs of industries. Our ultrasonic NDT technologies help clients ensure accuracy and precision during dissimilar metal weld inspection. Pre-service flaw detection allows industries to mitigate risk and maintain quality and productivity. Contact us today to learn how we can deliver solutions to optimize productivity, safety, and total cost of ownership.

High-temperature hydrogen attack (HTHA) is an unpredictable hazard that can damage the strength and ductility of steel or stainless steel. HTHA mostly occurs in hydrogen environments that are typically present in refineries, petrochemical plants, and chemical facilities subject to high temperatures and stress. HTHA and stress corrosion cracking can lead to degradation of metal quality. Such flaws can be difficult to identify, which means the intensity of risk associated with the damage is even higher.

It can be easier and less damaging to maintain a safe operational system with early identification of stress corrosion cracking and HTHA. This can be done with the advantages offered by advanced non-destructive testing (NDT) techniques, which can ideally inspect for possible flaws without damaging the component or increasing the downtime within the operation.

Challenges With Inspecting Cracking and HTHA Corrosion

HTHA and stress corrosion cracking are two very dangerous flaws that can occur across various industries—mostly due to their difficult-to-detect nature. HTHA occurs in metals such as steel exposed to hydrogen under high pressure and temperatures above 400°F. At this high temperature, the carbide existing in steel absorbs the hydrogen to form air bubbles, leading to cracking. Similarly, stress corrosion cracks can be the result of a corrosive environment, high temperatures, and high tensile stress. The individual small cracks can grow and form larger colonies, decreasing the structural strength.   

Inspection to detect these flaws can provide early insight into any forthcoming issues, allowing industries to minimize the risk of operational failure and improve safety standards. NDT methods like ultrasonic testing (UT) and eddy-current testing (ECT) have been employed for their excellent flaw detection abilities across many industries. In recent years, the accuracy and efficiency of advanced phased array ultrasonic testing (PAUT) technology have made it a preferred choice for these types of inspections.  

Detecting Stress Corrosion Cracking and HTHA with Ultrasonic Inspection

The initial formations of stress corrosion cracks and HTHA are difficult to detect visually due to their very small sizes. A better way of identifying these flaws is with powerful ultrasonic testing techniques. Advanced PAUT instruments and probes can be highly efficient in detecting the location, size, and intensity of stress corrosion cracks and HTHA flaws. An ideal PAUT instrument has the capability to:

• Produce a scan of the inspection surface to provide high-resolution imaging. This can be instrumental in detecting the size of the microcracks and colonies.
• Focus beams to allow for identification of air bubbles and cracks as well as accurate positioning of these flaws. 

Advanced PAUT tools can also be utilized with the following inspection techniques to provide the best inspection results:

1. TOFD (Time-of-Flight Diffraction) is suitable to identify grain noise and A-scan signal clustering. Increased noise and cluster may indicate early-stage HTHA. This is used as an initial inspection technique along the metal surface and welds.  
2. With TULA (TOFD Ultra-Low Angle), it is easier to scan thicker metals. Increased noise and clustering identified with TULA can help indicate HTHA.
3. Live TFM (Total Focusing Method) can be used for further verification of these flaws and their appropriate characterization.

NDT Solutions: Accuracy and Efficiency in Detecting Stress Corrosion Cracking and HTHA

The ability to identify stress corrosion cracking and HTHA damage within the early stage of an operation is highly beneficial for industries to seek solutions before more damage is done. With the reliability of PAUT instruments such as Zetec’s TOPAZ 64, industries can ensure accuracy and precision in stress corrosion cracking and HTHA damage detection. Leveraging the cumulative advantage of PAUT, TOFD, TULA, and TFM can also act as an ideal strategy for industries in ensuring the operational quality up to the industrial standards. 

Zetec is a leading provider of non-destructive testing (NDT) solutions with a goal to provide critical inspection needs of industries. Our eddy current and ultrasonic testing technologies help clients accurately identify stress corrosion cracking and HTHA damage at its earliest formation stage, minimizing the risk and ensuring the quality of the metal component. To learn more about how we can deliver solutions to optimize productivity, safety, and total cost of ownership, contact us today.

Stainless steel is a widely popular material used in a range of industries including aviation, manufacturing, oil and gas, and more. Its corrosion-resistance properties and high strength make it a desirable material to work with even in a highly corrosive environment. The critical use of stainless-steel components in varying operations makes it mandatory to ensure that there are no flaws that can cause potential harm to the structural integrity of a component. This requires industries to leverage non-destructive testing (NDT) technologies during stainless steel testing.

The Need for Stainless Steel Testing

In a neutral and corrosive environment, stainless steel equipment is highly desired for its excellent properties. However, it is prone to flaws so it must be thoroughly inspected. Most of the flaws can be detected in the heat-affected zone around the welded joints. However, there can be metallurgical flaws in stainless steel resulting from inaccurate manufacturing parameters. During stainless steel testing, technicians can look for the possible presence of inclusions and cracks. It is also ideal to test for corrosion and thickness profile, especially in the heat-affected welded joints.

The Benefits of Using NDT for Stainless Steel Testing

NDT methods, ultrasonic testing (UT) and eddy current testing (ECT), are ideal for testing stainless steel structures and equipment to ensure their strength and integrity.

UT Inspection of Stainless Steel

In the welding process of stainless steel, factors like lack of proper surface preparation can increase the possibility of inclusions and resulting pores and cracks. Although the anisotropic coarse-grain structure of stainless steels and dissimilar metal welds can cause inspection challenges, using advanced UT techniques with innovative equipment can result in efficient, robust inspection procedures.

Ultrasonic testing involves a transducer emitting ultrasonic beams to the stainless-steel surface. The beams can be focused, and the amplitude of the reflected beam compared to identify the type, sizing, and location of the flaw. Phased-array ultrasonic testing (PAUT) with low-frequency 2D matrix array probes can be ideal to better navigate this challenge. The ability to vary frequency levels makes the inspection of components with varying wall thickness possible and the identification of a wide range of flaws easier.

 ECT Inspection of Stainless Steel

Eddy current testing can be useful in testing surface flaws like cracks in stainless steel tubes. An ECT probe induces an alternating current into the conductive stainless steel creating a field. Any change in the amplitude is an indication of potential flaws like cracks in the component.

With eddy current array (ECA) technology, the examination can be simplified. The ability to provide surface and near-surface inspection for a wide range of geometry also provides industries with the time-saving and cost-effective inspection opportunity.    

In corrosive or extreme temperature applications, where stainless steel components can be an important part, the strength and integrity of such equipment are crucial. The reliable testing ability of NDT methods like PAUT and ECA ensures the proper identification of stress cracking, corrosion, inclusions, and other types of degradation. The pre- and in-service inspection ability provided by innovative PAUT and ECA probes are advantageous for industries to ensure operational and employee safety.  

UT and ECT Solutions for Stainless Steel Testing

With stainless steel being used in different application areas, it is important for industries to recognize the potential problems that can be present in different stress or temperature limits. Especially in critical applications involving corrosive environments, where stainless steel is trusted for its mechanical properties, the need for flaw detection is even higher.

NDT technologies are now an integral part of industries responsible for ensuring the integrity of stainless steel components. In stainless steel testing, UT and ECT technologies can identify discontinuities that may impact structural integrity. The ability to identify a flaw allows industries to take proper action to ensure the safety and productivity of the operation.

Zetec, a leader in NDT technologies for over half a decade, is here to assist with your stainless steel testing needs, offering a wide range of eddy current and ultrasonic non-destructive testing technologies. To learn more, contact us today.

In industries like oil and gas where pipelines are the major components in operation, issues like stress corrosion cracks can be a common occurrence. Stress corrosion cracking is often induced in the pipelines as a result of excessive stress due to high pressure and corrosive environmental agents. These cracks can be difficult to detect in the beginning but may increase to form patches consisting of individual cracks. This type of flaw in process piping can be catastrophic and severely damaging to the serviceability and safety of an operation.

As a preventive measure, it is crucial that pipes are inspected for potential stress corrosion crack colonies. With ultrasonic testing (UT), it is possible to monitor the quality and strength of a pipe system through early flaw detection.   

Stress Corrosion Cracks in Pipes

There are many factors involved in the formation of pipe corrosion cracks. This may include:

• The characteristics of the pipe material including type and composition of carbon steel, steel grade as well as the manufacturing process and its cleanliness can indicate the susceptibility of the pipe to corrosion-induced cracking.
• Environmental factors such as soil type and moisture content can dictate the possible formation of stress corrosion cracks.
• The part of the pipeline where coating damage has occurred can be the inception point for the flaw due to its inability to resist a corrosive environment.
• The presence of cathodic protection current can give rise to a carbonate or bicarbonate environment, triggering high or near-neutral pH stress corrosion cracks.
• High tensile stress in the pipelines due to external or internal load factors can lead to cracking in the pipes.       

The cracks induced in the pipeline due to these potential factors can be difficult to visually detect, but with time, the cracks can grow to form colonies which can ultimately lead to structural failure. Especially in certain ERW (electric resistance welded) pipelines and other select seam types, this type of issue can be linked to operational or safety risks.

The early detection of minor cracks in pipelines is key to preventing the risk of failure. Phased array ultrasonic testing (PAUT) is the ideal choice in this process.

Effectiveness of PAUT Inspection in Detecting Stress Corrosion Cracks

Corrosion can wear the surface of the pipeline affecting its performance and strength. Therefore, it must be detected as early as possible. Oftentimes, pipelines are buried, making inspection even more challenging. To prevent the sudden failure of a structure due to undetected corrosion, non-destructive testing (NDT) is often relied upon because of its ability to help technicians identify even the microscopic flaws and deviation in a component. PAUT inspection provides an ideal option for corrosion detection in the pipeline system. Advanced ultrasonic technology can:

• Identify variation in metal thickness, which can be an indication of corrosion.
• Detect extremely fine cracks and colonies in metals of different thicknesses.
• Provide high-resolution imaging that can be used for locating and determining the size of a flaw for further remedial measures. 

With the ability to locate and identify a flaw in the early stages of its formation, technicians can focus on repairs or other measures to maintain structural and operational integrity.

NDT Ensures Strength and Minimize Risks

The phased array ultrasonic testing method provides a focused view in the inspection of process piping to detect stress corrosion cracking. The ability to locate and identify the type and size of the flaw provides the opportunity for preventive maintenance of the pipe system. The result can also be further utilized to identify the potential root cause of the flaw. With easy-to-use PAUT application-specific probes and advanced instruments, industries can focus on the quality, safety, and cost-efficiency of the operation.    

Zetec is a global leader in nondestructive testing (NDT) solutions for the critical inspection needs of industries. Our ultrasonic technologies help clients ensure the quality of process pipes with thorough detection of stress corrosion crack. Contact us today to learn how we can deliver solutions to optimize productivity, safety, and total cost of ownership.