The Advantages of Eddy Current Tests on Large Area Surfaces

Eddy current testing (ECT) has become one of the most popular nondestructive testing (NDT) techniques for inspecting conductive materials for surface and subsurface flaws. Eddy current testing of large areas or complex surfaces can be taken to the next level with an eddy current array (ECA)—a system capable of producing detailed three-dimensional renderings of flaws, including extremely small indications that can elude other NDT techniques.

ECA has the benefit of quickly performing an eddy current test on a large area without the need for coupling fluid, making it an ideal technology for identifying cracks, signs of fatigue, corrosion, and other surface and near-surface flaws. Here, we can discuss some of the major types of flaws that affect metal surfaces and how ECA can improve the ability to detect them.

How ECT Works to Uncover Flaws

Basics of Eddy Current Testing (ECT)

ECT uses the principle of electromagnetic induction to test for flaws in conductive materials. In its most basic form, a single-coil ECT probe is energized with an alternating electrical current, which generates an oscillating magnetic field around itself. When the probe approaches a test piece made of a conductive material, it induces an eddy current in the material.

Any flaws or discontinuities in the test piece cause changes in the eddy current’s amplitude, measured by the probe and used to generate a visual representation of the test surface.

ECT has several advantages over other NDT techniques:

  • Can be used with both ferrous and non-ferrous materials, as long as they are electrically conductive
  • Can penetrate non-conductive coatings
  • No coupling fluid or surface preparation required
  • Produces a computerized record of the inspection

Common applications of ECT include surface inspection, corrosion detection, bolt hole inspection, and weld inspection.

Eddy Current Array: Eddy Current Testing for Large Areas

Some of the drawbacks of single-coil ECT are that it can only be used to test a small area at a time and can only reliably detect flaws that are oriented perpendicular to the eddy current. This is fine when the direction of potential linear flaws like cracks is known, but getting a thorough picture of the test piece, including flaws in multiple orientations, requires multiple passes, increasing inspection time. 

The eddy current array (ECA) overcomes this limitation by combining several single-coil ECT probes on a grid that produce signals in both the axial (direction of scan) and transverse (perpendicular to scan) directions. The coils fire in a coordinated way to create a three-dimensional image of the surface and subsurface in a single pass, simplifying eddy current testing of large areas and speeding up inspection times by as much as 95 percent compared to traditional probing techniques.

Compared to single-coil ECT, some of the advantages of ECA include:

  • Faster inspection time
  • Easier technique
  • More accurate and repeatable results
  • More information captured in a single pass
  • Can find linear flaws 
  • Provides high confidence in full surface coverage
  • Powerful reporting and data recording capabilities

Types of flaws

Several types of flaws can occur on metal surfaces. ECA inspection is effective at detecting most types of linear and volumetric discontinuities, such as:

  • Cracks
  • Incomplete fusion/separation
  • Pitting corrosion
  • Porosity/voids

Linear flaws: Cracks, Laps, Separation

ECA inspection is ideal for detecting cracks and other linear discontinuities caused by fatigue or manufacturing flaws. It can identify all kinds of surface and internal cracks, including:

  • Stress/fatigue fractures
  • Tip cracks
  • Weld root cracks
  • Forging bursts
  • Incomplete fusion/forging laps

The best eddy current instruments can detect cracks for complex inspections like tubing using multiple frequencies and dual options and can detect cracks as small as 0.1 mm or less in depth.

The 3D renderings produced by ECA inspection make it easy to see where cracks are developing and their orientations. Furthermore, ECA can show variations in crack size and depth that may not be visible with other NDT techniques like liquid penetrant testing (PT) or magnetic particle testing (MT).

Watch our webinar to learn more about the advantages of eddy current array (ECA) testing compared to liquid penetrant testing (PT) and magnetic particle testing (MT).

Volumetric flaws: Corrosion, Pitting, Voids

ECA’s three-dimensional imaging capability also makes it effective for identifying volumetric flaws like voids, pitting corrosion, or generalized corrosion and distinguishing these flaws from linear ones.

ECA effectively penetrates tough welding sections to detect indications of corrosion. The signal-to-noise ratio can help pinpoint the slightest deviations or material losses resulting from corrosion, in addition to abnormal changes in thickness. 

Corrosion can often produce multiple flaw types simultaneously, such as pitting and corrosion cracking. The ability to see indications in both the axial and transverse directions makes it easier to distinguish between these flaw types, providing a clearer picture of the problem and its causes. 

While single-coil ECT, PT, and even visual inspection might all be able to detect corrosion, the specific types of flaws might not be obvious. For example, ECA’s axial and transverse channels clearly distinguish between volumetric flaws visible on both channels and linear flaws, which only show up on the channel perpendicular to the flaw.

ECA Technology for Eddy Current Testing on Large Areas

From detecting extremely small indications to performing eddy current tests on large area surfaces in a single pass, Zetec can help.

Zetec has been a global NDT leader for over 50 years, and we’re constantly advancing the science and technology of eddy current testing and other NDT technologies. Zetec’s proven expertise and product portfolio set the standard for the inspection needs of the aerospace, transportation, power generation, manufacturing, and oil and gas industries.

When it comes to performance, accuracy, dependability, and affordability, eddy current array solutions may be a key asset. To learn more about our ECA inspection solutions for your company, contact Zetec today.

Using Ultrasound Plane Wave Imaging in NDT

Using Ultrasound Plane Wave Imaging in NDT with Zetec's Emerald.

Across many industries, technicians and engineers have strived for high accuracy and efficiency in flaw detection. In the medical field, this has been achieved with the help of Plane Wave Imaging (PWI) technology. Plane wave imaging holds the promise of producing high-resolution imaging through scan and precise flaw detection. Now, this technology is gaining popularity in other industries as a data acquisition method for ultrasonic non-destructive testing (NDT)

Rapid data acquisition and analysis through ultrasound plane wave imaging —often in conjunction with full matrix capture (FMC) and the total focusing method (TFM)—provide many advantageous prospects for industries.

Ultrasound Plane Wave Imaging

The phased array ultrasonic testing (PAUT) NDT technique has been mostly preferred by industries for its ability to generate focused imaging, accurate results, and faster inspection. Often, for more advanced inspections this can be supported by FMC data acquisition and TFM algorithms to digitize and analyze the data for later or even real-time processing. The A-scan signal data thus stored in the form of a matrix grid is instrumental in developing high-resolution imaging for flaw detection. 

However, TFM requires more computing power for the analysis of large numbers of data in the matrix grid. In addition, FMC data can generate extremely large size data files and requires extensive processing power for real-time data reconstruction. As a result, many inspections rely on heavy external computer processing for TFM image reconstruction.

Plane wave imaging simultaneously excites all available elements in an array for the transmission of ultrasonic signals at different angles. Simultaneous excitation means a single transmission circuit can be used for the process. Plane wave imaging also reduces the number of excitation required to capture the data. Few excitation and wide area coverage allow for faster data collection, processing, and analysis. The data collected is stored in form of a matrix. At each angle, the plane wave data acquisition recreates the dynamically focused image at different depths. By adding these images, the final image can be achieved. This resulting image can be used to identify the type of flaws in the component. 

Benefits of Utilizing Ultrasound Plane Wave Imaging

Compared to TFM/FMC, ultrasound plane wave imaging offers many advantages in data acquisition and processing. For industrial NDT, plane wave imaging can facilitate:

  • Less computation time due to increased scan area and less excitation requirement
  • High-quality data and high-resolution imaging
  • Single transmission circuits that lead to ease of inspection with less complicated hardware 

In addition to the advantages plane wave imaging offer, industries should also be wary of some issues:

  • With a reduced number of excitations, the amount of data or signals collected can be less.
  • High computation power may be required for real-time data processing. 

Ultrasound Plane Wave Imaging Solutions for Improved flaw Detection

Industries are now leveraging the advantages of ultrasound plane wave imaging for NDT data acquisition and analysis. Zetec has introduced the EMERALD system with powerful TFM image processing capability. EMERALD offers:

  • Plane-wave imaging as a powerful data acquiring technique with up to 128 elements 
  • Advanced plane wave image reconstruction ability with A-scan signal processing along every angle and acoustic path

Using ultrasound plane wave imaging for NDT allows industries to focus on efficiency and productivity through its advanced image processing and flaw detection ability. Look for systems that offer fast and efficient onboard processing capabilities, along with superior signal quality designed to achieve high amplification without distortion. This can make a big difference in inspection productivity. 
With the right equipment, technicians and engineers can quickly analyze images—even from complex configurations to help foster quality and safety in industrial operations.

Zetec is a leader in nondestructive testing solutions with options for advanced ultrasound plane wave imaging algorithms for precise image capture and flaw detection. To find the NDT equipment which best suits your testing needs, contact us today!

Advanced NDT Software for Metals, Materials, and Composites

Nondestructive testing (NDT) methods, such as eddy current testing (ECT) and ultrasonic testing (UT), provide the ability to inspect for surface, subsurface, and internal discontinuities or flaws, ensuring the safety and reliable performance of welds, components, and structures. However, NDT methods are only effective if properly used. If NDT equipment isn’t set up correctly, for example, defect indications might not be visible. Likewise, defects can be missed or misclassified if technicians are not adequately trained to interpret the results.

Fortunately, these concerns can be largely addressed by facilitating as much of the inspection process as possible using NDT software tools. In this post, we will discuss how advanced NDT software can improve the value and reliability of both eddy current (ECT) and ultrasonic testing (UT).

How NDT Software Can Alleviate Testing Concerns

Whether using ECT or UT technology, an effective NDT process must be able to:

  • Consistently identify critical indications
  • Produce results quickly
  • Make it easy to see trends over time

Traditionally, analysts had to interpret NDT results off-site or in a less visually intuitive approach, which can present a few problems. This type of analysis requires highly experienced, trained technicians to identify defects accurately. The process is time-consuming, and the subjectivity involved opens the inspection process to variation.

Now, many industries may be replacing this type of analysis with advanced NDT software that can help control the scan, collect and analyze data in real-time, and generate images, greatly improving speed and consistency over legacy analysis. For example, 2D or 3D images generated by software such as UltraVision allow technicians to quickly and easily identify defects. In addition, the right NDT software produces accurate, consistent, fast, and easy results for the technician to interpret.

Below is a summary of some features NDT software can provide and how they can improve inspection processes:

Feature Advantage
Coverage MappingProvides understanding of detection capability and inspection coverage
Inspection SimulationMakes testing more predictable
Analysis ToolsReduces inspection time, makes results more repeatable/reproducible
Real-Time AnalysisProvides immediate awareness of indications
Flaw Detection and ClassificationImproves detection rate and consistency of defect classification
Noise MonitoringReduces false positives and streamlines inspection
User Configuration LockingSafeguards against errors and guarantees control over results
Historical Data ComparisonProvides early warning of problems and better understanding of process capability
For more information about software solutions for Ultrasonic Testing (UT), see our UltraVision software packages.

Industry Applications for NDT Software

The benefits of NDT software can be found anywhere UT or ECT could be employed for inspection. Below are some examples of how NDT software can improve inspection processes in the oil and gas and aerospace industries:

Oil and Gas Pipelines

UT is commonly used for weld inspection and corrosion mapping in pipelines—a time-consuming process. By implementing UT equipment with built-in NDT software, the technician can create setups and calibrate the instrument in minutes rather than hours. NDT also software allows inspection parameters to be changed on demand, saving inspection time. 

Aerospace Components

Aerospace manufacturers and operators use ECT to check for cracked bolt holes. Bolt holes may be susceptible to cracking during the manufacturing process and operation due to over-tightening fasteners. However, there is a high potential for false positives caused by burrs, scratches, or other non-critical imperfections. Even worse, noise from these indications can obscure actual defects.

ECT software can help manage signal-to-noise ratio so that technicians can more easily distinguish between burrs or scratches and fine cracks. This can greatly improve the reliability of aerospace bolt hole inspections, which can be critical to flight safety.

See our software solutions for Eddy Current Testing (ECT).

Improving Inspection with Advanced NDT Software

NDT software is growing faster, more powerful, and more user-friendly all the time, and industries are taking notice. The latest software can help simplify the inspection process, analyze data in real-time, and generate 3D visualizations while ensuring the most accurate results possible. Industries that rely on NDT processes should be aware of the software options available to perform faster, more reliable testing.

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

Eddy Current NDT for Power Busbars

Power busbars are an integral part of heavy-duty power-dependent applications. Busbars are the strip or bar of copper, brass, aluminum, or other metals that help in power distribution by collecting the incoming current and distributing them through the outlet terminals used in high-power spacecraft, wind turbines, and other electrical systems.

Busbars need to be free of defects to ensure proper functioning. Inspection with eddy current (EC) testing before installation and periodically while in use is a helpful way to guarantee their quality. 

Functionality of Power Busbar and Potential Defect Development

Power busbar can be typically found inside switchboards and busway enclosures to help conduct electricity from one electrical terminal to the other. They are assigned a typical voltage, mostly high, and can be found in various sizes and shapes, i.e., bars, strips, and rods.

The busbar acts as a junction from where collection and distribution of power can be made possible; it is composed of conductive materials like copper or aluminum. Different circuits are connected within this junction along the busway rather than branching off of multiple circuits from the main switch. Each power busbar has an isolator and a circuit breaker. The circuit breaker trips when the wiring fault is detected, saving the main switch from being damaged. The damaged busbar can also be easily disconnected and replaced.

Power busbars are cost-effective and durable solutions to wirings. However, material composition and mechanical use of the power busbar can lead to defect development. Under stress and temperature fluctuation due to high current and voltage, fatigue cracks can develop, especially at the bent area. 

This defect can ultimately lead to arching and shorts in the power transmission system. With non-destructive testing (NDT), the power busbar can be examined for possible defects even before the installation. The reliable NDT assessment using EC testing can help massive power generation industries test busbar for surface cracks at different installation and operation phases, thus saving massive repair costs.

Eddy Current Inspection Approach to Power Busbar

In a simple electric panel to large-scale wind generation turbines, the power busbar performs a critical function. Inspecting this component with the advanced eddy current array (ECA) can help prevent failures and potential hazards. 

For a wide range of geometries, the frequency can be optimized in ECA to facilitate greater sensitivity in scanning. With the help of multi-element probes, ECA can inspect larger areas in a single pass as compared to conventional EC testing. In power busbar inspection, surface and near-surface cracks along the surface and bend areas can be simplified with ECA probes which can facilitate:

  • Faster inspection with larger coverage area
  • Flaw detection in varying geometries and orientations
  • 2D or 3D scanning ability
  • Improved defect sizing and data recording capabilities

With advanced eddy current testing solutions from Zetec, power busbar inspection can be made easier.

Learn more about Zetec’s solution for Wind turbine busbar inspection.

Solving Busbar inspection Challenge in Power Generation with NDT

Power busbar is used in almost every application and industry where power is generated. The safety of the power system depends on the quality of the power busbar, which should be free of defects. With Zetec’s solutions, such as Surf-X array probe and MIZ-21C instrument, technicians can easily inspect multiple busbars simultaneously with much more sensitivity and accuracy. 

  • Surf-X Eddy Current Array probe provides flexibility in inspection, which allows assessment of power busbar such as that of wind turbine towers with complex geometries. 
  • MIZ-21C, a portable, handheld instrument provides excellent user interface, display, and data recording capabilities facilitating defect sizing for improved flaw detection in critical applications. 

Quick inspection turnarounds with Zetec’s solution provide an efficient and economic way to ensure the power distribution system operates at its finest. 

Zetec provides portable and flexible ECA instruments that can help serve your NDT needs in the power generation industry with efficient power busbar inspection. Contact Zetec today to create your custom power busbar inspection solution.

Pipe Weld Inspection Methods for Ferritic and Austenitic Metals

When discussing pipes and their maintenance, we usually think of oil and gas industries and the vast extent of pipelines that are on the rise. But there is more to the application of pipes than just petroleum transport. For example, they are commonly used in nuclear, biopharmaceutical manufacturing, and food and beverage industries, all heavily dependent on pipes and tubes for proper operation. This also gives rise to the need for pipe weld inspection in these industries. 

Pipes and welds in such industries can be required to adhere to strict sanitary and structural standards. To serve this need materials such as steel, or other austenitic materials are mostly used. To examine if the weld performed in such pipe materials are strong, flawless, and pure, various non-destructive testing (NDT) technology can be used. 

Ferritic and Austenitic Metal Pipe Welds

Carbon steel has been a go-to material for industries when it comes to piping for excellent structural integrity. However, carbon steel pipes don’t quite fit the role for industries such as biopharma and food processing, where sanitation and purity are the topmost requirements. In addition, the corrosive behavior of the metal can be an issue that can be further exacerbated by acids and bases in the food or chemical content. Ferritic and austenitic stainless steels are thus preferred due to their corrosion-resistant properties. 

Austenitic and ferritic metals can provide a similar structural strength as carbon steel while adding corrosion-resistant features to the equation. The weld priority of these pipe materials can, however, be unique due to their varying microstructures.

Ferritic generally have poorer weldability than austenitic metals. So, welding such material can result in loss of toughness and ductility while increasing the possibility of hot cracking and embrittlement in the heat-affected area. Similarly, for austenitic metal with low thermal conductivity properties, heat input during welding requires careful consideration. They are also equally susceptible to corrosion and microcracking. 

Any flaw developed due to inaccurate weld can cause contamination which is a major concern for industries adhering to strict sanitary regulations. To avoid such a situation, pipe weld inspection with NDT is befitting. 

NDT for Pipe Weld Inspection Ensures Industry Standards

Pipe weld inspection of stainless steel can have technicians looking out for flaws such as microcracking, corrosion, inclusion, and lack of fusion. These are all the results of an improper weld process. While visual, magnetic particle and radiographic testing have been used, industries are increasingly choosing ultrasonic (UT) and eddy current (EC) testing methods

EC inspection method is favorable in identifying surface or near-surface flaws such as microcracking. As the eddy current is induced in the metal, the variation in the magnetic field can be detected, indicating the possibility of cracks in the surface that may not be obvious during visual inspection. Similarly, using the PAUT (Phased Array Ultrasonic Testing) method, in-depth flaws such as inclusions, lack of weld fusion, cracks, and pores can be easily identified with the help of ultrasonic waves traveling within the pipelines.   

The utilization of these inspection techniques is important if operational efficiency is to be maintained and contamination avoided. Contamination can pose severe health risks to the consumer. EC and UT can help industries avoid this situation by detecting flaws pre-installation and periodically while in-service. 

Maintaining Safety and Sanitary Standards with NDT

Once welded, NDT solutions can help in analyzing the quality of the pipes and tubes. Through periodic inspection, flaws developed with time can be detected, initiating the need for repair and maintenance. NDT methods like EC and UT can ensure pipe weld inspection in-service with minimal disruption of the operation. Through effective inspection, any source of contamination can be easily eliminated, helping industries meet their sanitary standards and maintain their cost-effectiveness and productivity.

Zetec can support your pipe weld inspection needs with advanced EC and UT equipment on the market. For more information, contact Zetec today to get a custom NDT plan that can serve your industrial sanitary requirements. 

Pipeline Weld Inspection: Your Complete Guide to Visual and NDT Inspection Methods

Almost 5,512 pipeline incidents were reported from 2010 to 2018 in the United States alone. This data says a lot about the need for inspection of such crucial infrastructure around the world. Pipeline failure can be extremely damaging; thereby, the risk for human lives, the environment, and damage and repair costs can be massive. Pain points like welds are contributing factors to such failure. To identify such risk areas and foster operational safety, exploration for advanced inspection methods is a must. 

Exploring Pipeline Weld Inspection Techniques

Welding of pipelines in either upstream, midstream, or downstream oil and gas operations needs to be of high quality if long-lasting performance is to be expected. Extreme temperature, pressure, and chemical interactions are other reasons why robust welding is desired. But given the challenge associated with the welding of pipelines, i.e., potential weld flaws, difficult weld setup for different pipe sizes, and improper welding around complex geometrical areas, the inspection need becomes imperative.

Over the years, various inspection methods have been implemented by industries to cover a wide range of inspection needs of pipeline welds. Based on their effectiveness, some of these types of inspection techniques are discussed below: 

  1. Destructive testing: Destructive testing focuses on inspecting the integrity of the pipe material itself and that of the welded joint through various tests to examine the metals’ robustness up to its failure point. The detection of point of failure allows technicians to analyze the weld quality and study the impact of load and stress on the joint. The weld certified through destructive testing can be set as the standard for pipeline welding and closely recreated for future operations.

The major drawback of this inspection system is its inability to represent all load conditions during a sample test. The weld sample used is completely destroyed, which increases waste, manufacturing and inspection costs. The test is basically used for certification purposes; thus, the weld quality cannot be accurately assured each time under a different operating environment.  

  1. Visual inspection: Visual inspection is the primary inspection method all technicians go for to make assumptions of the weld quality in pipelines. It is the most uncomplicated and inexpensive method of inspection and an effective one in recognizing any major weld issues as it occurs. Visual inspection can be performed pre-, during, or post-weld, which prevents the flaw from carrying on onto the next phase of the process. The more observable flaws such as cracks, weld splatter, distortion, incomplete fusion, and larger pores can be located easily. To inspect for leaks in pipeline welds, a basic approach is to pressurize the pipeline and use media like soap water that can visualize air escaping in the form of bubbles. 

The disadvantage with this inspection method is its inability to capture all minor and underlying flaws in the weld surface. However, it can be used as a way to prevent significant flaws from occurring, reducing the need for extensive nondestructive testing (NDT) analysis. 

  1. Dye penetrant testing: Dye penetrant testing is often considered to be an advanced visual inspection technique. As the visible dye penetrant is applied to the weld surface, any cracks or pinholes not easily identified during visual inspection can be displayed as a contrast in color. Although quick, portable, and suitable for all kinds of geometries, only surface flaws on smooth surfaces can be identified, which can be a problem, especially for critical structures like pipelines.   
  1. Nondestructive testing: Nondestructive testing has been an industry choice due to its effectiveness and ability to inspect pipelines without causing them any damage. Advanced NDT instruments and probes have proved their efficiency in pipeline weld inspection. NDT can facilitate precise identification of all major and minor flaws in the weld surface and sub-surface to give a complete overview of the weld quality. This is supported by the flexibility and portability of advanced NDT instruments, which further provide the benefit of inspection in complex areas, on-site inspection, and real-time inspection, desirable features for pipeline weld inspection. 

The major issues concerning destructive and visual inspection are their inability to detect all flaws and discontinuities within the weld, causing a major efficiency problem. The advantage of precision, accuracy, and flexibility that NDT provides is why its favorability over other inspection techniques has been increasing.

Improving Inspection Efficiency with Advancement in NDT

As we discuss the effectiveness of NDT for pipeline weld inspection over other inspection techniques, the question that arises is how does NDT make it possible. Here are some reasons why:

  1. Complete inspection: With advanced eddy current (EC) and ultrasonic testing (UT) instruments, a wide range of flaws in the weld can be identified. Flexible probes and scanners mean an inspection can be done even in complex geometries such as pipe bends. A complete scanning allows for effective data analysis.
  2. Portable scanning: With portable NDT solutions, easy and speedy inspection is possible. On-site inspection ability of instruments reduces travel times and time between scans, plus wider coverage from probes increases inspection efficiency. Portability also improves inspection efficiency in low-clearance or difficult to access areas of the pipeline by eliminating the need to create access or be exposed to potential hazards.  
  3. Scalability: With instruments configurable to scale and the ability to combine multiple instruments for highly challenging volumetric inspections, the time taken for complete pipeline weld inspection can be reduced.   
  4. Improved data analysis: Advanced NDT scanners and probes can scan and capture large amounts of data quickly. Faster analysis using advanced instrumentation and software improves communication and reduces inspection downtime. With real-time analysis, it is possible to speed up the process further. The improved A and C-scan display capabilities foster accuracy during flaw detection and characterization.

Pipeline weld inspection is made easier for oil and gas industries with advanced features of NDT instruments, software, scanners and probes. By giving technicians access and coverage for inspection, improved flaw detection, and weld quality analysis can be achieved. 

Pipeline Weld Inspection is Made Easy With NDT Solutions

The risk factor involved in oil and gas pipelines and welds is huge, thus requiring accurate inspection technology. With ultrasonic scanning technologies such as the Weld Crawler and ElbowFlex scanner from Zetec, portable and flexible inspection ability can be achieved. In addition, Weld quality ensured through advanced NDT instruments, probes and software can allow oil and gas industries to minimize hazards and needs for repairs and look forward to a more profitable operation.  

Zetec specializes in advanced eddy current and ultrasonic testing solutions that can match your pipeline weld inspection needs. Our portable scanners and NDT weld crawlers can help in reducing your inspection downtime and improve productivity. To learn more, contact us today!

Discerning Processing Discontinuities During Manufacturing

It is normal for the metal or components to go through various metallurgical changes during the manufacturing process. This holds true during machining and fabrication phases, including melting, rolling, stamping, forming, grinding, welding, plating, or heat treating. During these processes, it is common to develop some processing discontinuities. Investigating the extent of these discontinuities can be challenging for technicians, especially if they rely on visual inspection.

Nondestructive testing (NDT) technologies effectively identify material imperfections at all stages of production without damaging the properties or performance ability of the material.  In particular, Eddy current (EC) testing and ultrasonic testing (UT), can look into these processing discontinuities for in-depth analysis and keep them off the production line. 

Understanding Processing Discontinuities In Manufacturing Setting

Discontinuities originate when the materials are subjected to extreme stress or temperature to alter the physical or chemical properties to satisfy the manufacturing needs.  These may appear in the form of inclusions, cracks, laps, seams, laminations, shrinkages, cold shuts, voids, and so on. Depending on when and how they are formed, processing discontinuities can be classified as:

  1. Primary processing discontinuities: These discontinuities occur in the primary manufacturing phases when the metal ingots are worked down using casting, hot and cold forming, and rolling processes to give it a desirable shape and size. Poor practices, rapid temperature changes, extreme stress application, and improper surface preparation contribute to the following types of primary processing discontinuities:
Casting discontinuitiesPorosity, cold shuts, shrinkage, dross
Rolling discontinuitiesLaminations, stringers
Forging discontinuitiesLaps, bursts
  1. Secondary processing discontinuities: These discontinuities originate during the finishing operations, such as grinding, heat treating, plating, grinding, welding, and machining. The most prominent types of secondary processing discontinuities include:
Machining discontinuitiesTears
Grinding discontinuitiesCracks
Heat treating discontinuities Stress cracking
Welding discontinuities Undercut, lack of fusion, porosity, cracks, inclusions, lamellar tearing

As industries use these processed materials further down the production line, ensuring their defect-free status becomes vital for analyzing the safety and quality of the product. This confirmation can be achieved with EC and UT methods of NDT testing. 

Volumetric Inspection of Processing Discontinuities With NDT 

From raw metal ingot to the processed final product, at each stage of production, NDT can recognize indications of flaws. With eddy current testing, the probability, and accuracy of detecting surface or near-surface flaws increases. With ultrasonic testing, in-depth, volumetric subsurface flaws can be identified by focusing on the ultrasonic beam and analyzing the deflection. 

Although the accuracy and precision in an inspection are an advantage, the sheer scale desired for maintaining a healthy production level in the manufacturing industry can be challenging for complex inspections using regular NDT instruments. NDT instruments with scalability options can be used as a solution. These instruments can be configured to scale, and multiple units can be stacked together and operated in parallel to cover a wide inspection area. This approach is advantageous for the following reasons:

  • Large volumes of data collected in a single scan can help in detailed inspection and analysis.
  • Volumetric scanning increases inspection speed fostering higher productivity.
  • Real-time inspection can help in the speedy analysis and immediate filtering of defective products.   

With the flexibility to inspect complex geometries and scalability to test volumes of products, discontinuities during manufacturing can be easily discerned while avoiding bottlenecks in the production environment.  

NDT Enhances Productivity and Quality

Metal processing is a common manufacturing phase, as is the inspection of processed products. Products with discontinuities can pose a significant risk to human lives, the environment, and the operation. NDT instruments can prevent these products with discontinuities from moving forward in the production stream. Through flexible, advanced, compact, and scalable instruments such as Zetec’s Emerald ( and Quartz, manufacturers can look forward to increased productivity of quality products. 

Zetec’s advanced NDT instruments with powerful inspection and data analysis capabilities can provide reliable inspection results to meet your manufacturing standards. Contact us today to learn more about how Zetec can help improve quality by identifying processing discontinuities.

Industrial Plant NDT Methods

With increasing quality and production demand globally, industries should constantly focus on quality improvement opportunities to gain a competitive edge. This means not only utilization of advanced manufacturing technology but also a constant lookout for flaws in machinery and products. Hence, the role of nondestructive testing (NDT) technologies becomes to identify these weaknesses or flaws in industrial settings that can damage product quality, productivity, and cost for the industry at large. 

With advanced NDT instruments and probes, accurate inspection and analysis of the material, industrial components, and products can be achieved. In addition, industrial plant NDT methods can foster improvement in performance and efficiency goals through quality control and regulatory compliance in industrial plants.

Inspection in Industrial Plants: NDT Methods Ensure Quality Control

Effective manufacturing requires regular inspection of industrial assets as well as manufactured components. NDT not only serves as a quality control measure but also fosters flaw detection at an early stage. In heavy manufacturing industries where large components may be manufactured, NDT supports the production environment by reducing waste, ensuring operational safety, and improving cost-efficiency.

Learn more about NDT for heavy manufacturing solutions

Similarly, in automotive industrial plants, NDT methods like ultrasonic testing (UT) and eddy current testing (ECT) can accurately and reliably inspect welds and composites in the components, helping to improve productivity and reduce downtime at all stages of production. 

Learn more about NDT in the automotive industry

Plants manufacturing pipes, tubes, and other steel components seek assessment for material integrity throughout the production process. NDT ensures this by examining material and welds for cracks, pores, laminations, inclusion, or other flaws in the production line.

Learn more about NDT for pipes, tubes, and steel products manufacturing.

Verifying Material Integrity Through NDT in Manufacturing

Carefully engineered machined parts and components can be key to precise manufacturing. To ensure these parts can be flaw-free, industrial plants generally look for inspection opportunities in forged, heat-treated, and machined components. This is applicable for many industries including automotive, pipes and tubes, or other heavy-duty manufacturing. 

Forged components go through extreme stress and temperature changes. During the process, the probability of occurrence of flaws like cracks or grains is high. Phased array ultrasonic testing (PAUT) and corrosion scanning methods can evaluate grain structure and identify parallel cracks and other inherent discontinuities even at greater subsurface depth with accuracy and precision. With volumetric scanning ability even along unconventional surfaces, a large amount of data can be analyzed to ensure product integrity.

Learn more about how ultrasonic testing of forging ensures heavy manufacturing product quality.

Many metallic components going forward in the production line face heat treatment to optimize their mechanical properties. However, the constant heating and cooling during the process can result in flaws and irregularities that can be difficult to detect visually. In industrial plants, the NDT method of ECT can monitor heat-treated components for potential cracks, void, inclusion, or other flaws. 

In the automotive industry, this can be done for components like gears, shafts, axles, and wheel bearings. With multi-frequency testing capabilities of ECT instruments, parts with improper heat treatment can be identified. This can help manufacturers to rule out flawed components and products to ensure safety and quality compliance. 

Read more about the use of eddy current testing for improper heat treatment testing in automotive manufacturing.

Quality assessment of fasteners or welds and metals or composites is an integral part of the NDT process in industrial plants. The combination of different material layers can make it difficult to identify voids, inclusions, and fractures developed between the layers. Similarly, weld flaws in irregular surfaces and complex geometries can also be difficult for technicians to spot. 

Especially in high-stake industries like automotive or aerospace, the flaws in final products can have serious consequences. With ECT and UT, manufacturers can ensure quality control through regular inspection of industrial components and products during each manufacturing process step. Timely detection can help industries reduce downtime while ensuring safety and quality. 

Learn more on how NDT provides inspection and quality control in manufacturing.

NDT Ensure Compliance To Industrial Standards

A wide range of industrial plants have been utilizing various NDT methods to ensure manufacturing quality control. However, ECT and UT have been the most prominent choice for their ability to detect surface and subsurface flaws accurately, perform volumetric inspections, and precisely analyze the data for different types of flaws. Zetec’s TOPAZ Phased Array Ultrasonic Instruments, NDT Paintbrush Scanner, Weld Crawler Scanner, as well as the MIZ-200 and InSite Eddy Current Instruments provide advanced solutions for the inspection of complex and critical components during the product manufacturing process. 

With the right NDT solution and effortless assessment, industrial plants can address flaws early and efficiently, ensure quality control and meet industry standards.

Zetec, with decades of experience, can help you find the right solution for industrial plant NDT. Contact Zetec to learn more about the best NDT method for you and discuss the custom inspection plans that match your needs.

NDT in the Space Industry

NDT space

The space industry has come a long way from Sputnik 1, the first-ever artificial satellite, to the New Shepard rocket with the first passenger flight. The recent extraordinary successes have shifted the immense focus of the world towards these space ventures. However, delivering a successful mission requires intricate attention to structural and other details of launch vehicles, satellites, and other payloads. One of the essential details for spacecraft and their payload is quality control of its components utilizing nondestructive testing (NDT) technology.   

Utilizing NDT to test spacecraft components and payloads is essential to ensure they perform with full efficiency for the long term without unexpectedany maintenance requirements. 

Areas to Pay Attention To for Spacecraft NDT

Space industries have focused on different ways to improve component quality and cost-efficiency in every space launch. However, with commercial space tourism on the rise, the stakes to increase spacecraft safety is higher than ever before. 

Whenever we think of a spacecraft, we can imagine the low gravity, extreme temperature variations, and immense pressure the launch vehicle can withstand. Like aircraft, there is also a necessity to keep the craft light yet strong enough to carry the payload. All these pre- and post-launch activities need to be completed without a single flaws in the system. Although each component is designed at its highest quality standards, flaws canare always be a possibility. A singular flaw can mean a catastrophic failure, massive investment loss, or loss of human lives in worst-case scenarios.

Composed of tanks for the propulsion system, launch vehicle frame, turbine and engine, pressure vessel, wings, fuselage, number of fasteners and other accessories, as well as composites and welds, the need for inspection is crucial. In addition, payloads such as satellites also need to be of excellent quality to ensure stable performance where no maintenance provision is available. Utilizing NDT, space industries assess the integrity of these materials and components without causing any damage. Identifying flaws early in the process can saves costs, ensures efficiency, and prevents hazards in this complex process. 

Importance of NDT for Successful Space Launch

Material quality, probable flaws, and their impact on the spacecraft’s performance and payloads can be examined utilizing NDT methods such as ultrasonic testing (UT) and eddy current (EC) testing methods. Additionally, the advanced probes, instruments, and software help industries fulfill the high NDT standards that the components are adhered to and provide the corrective maintenance opportunity.

  • EC testing facilitates inspection of flaws such as cracks and other surface flaws for components like spacecraft frame, turbine or engine, fasteners, and the heat-affected areas of the weld. Eddy current array (ECA) instruments and probes can test in complex and difficult-to-reach sections to detect minor surface and subsurface flaws, thus increasing the probability of flaw detection. 
  • Ultrasonic testing (UT) is most commonly used for NDT space. From thickness testing to corrosion detection, UT can effectively assess composite spacecraft structures, engines, and gears for the presence of cracks, corrosion, or inclusions. Advanced Pphased array ultrasonic testing (PAUT) instruments with TFM (Total Focusing Method) facilitate scanning along the complex geometries and wide surfaces for volumetric inspection in a short amount of time. 

NDT Ensures Mission Success

Construction and maintenance of the space shuttle and their various payloads are subjected to stringent inspection requirements. This is due to the immense risk it carries. The inspection should be carried out at greater speed with maximum accuracy and precision for the time- and quality-bound space missions. With PAUT and ECA methods of NDT, the space industry can easily detect minor flaws at an early stage, saving the project from major catastrophes. With quality components, space industries can venture into successful space missions.

Zetec is a leading provider of nondestructive testing solutions for inspecting spacecraft and payloads in the space industry. To learn more about our advanced NDT solutions, contact us today.

Nondestructive Testing for Metal Casting Defects

metal casting defects

As one of the earliest known manufacturing processes, metal casting has been a go-to metalworking process in industries for centuries. Oil and gas and nuclear industries have been casting steel and other materials for components like pipes, elbows, or risers. 

The casting process involves pouring hot molten metal into the die or mold and letting it solidify to get a desired geometrical shape. This technique has made it easier to design custom or complex geometrical components in an economical way. As a result, we can often see cast metals being used in our daily lives in, for instance, engine blocks on cars, train wheels, or traffic light posts. 

However, before these components are put to use, they must go through an elaborate inspection process. This is required because the molten metal may leave pores or voids within the cast during solidification. The probability of these flaws developing into more severe cracks during stress exposure is high. Nondestructive testing (NDT) can easily identify these metal casting defects without damaging the component. The quality and safety assessment through NDT is vital to ensure that the component is fit enough to be used.

Types of Metal Casting Defects

As with any other manufacturing process, there is a probability that defects may occur during metal casting. Usually, heat treatment of the metal or metallurgical factors can play a role in developing metal casting defects. These defects can exist in metal in many forms, such as:

  • Porosity: When the metal is liquified, it dissolves a large amount of gas within it. When the molten metal is poured, these gaseous bubbles are trapped. During solidification, these trapped gases induce the formation of pores in the metal.  
  • Inclusion: Inclusion is another common occurrence in cast metal. The impurities or contamination present in the molten metal or the mold can affect the ductility or strength of the component. The concentration of these foreign matters in one spot during solidification can be even more severe, leading to cracking.  
  • Cracks: Cracks can be observed once the cast metal has been solidified. There can be many reasons for the cracks to form, including mold design faults, shrinkage, uneven cooling, excess porosity, and thermal stress. 
  • Shrinkage: Shrinkage is a major concern for industries during metal casting. Expansion and contraction are leading reasons for shrinkage. Closed shrinkage defects occur when the poured metal starts to solidify, and hot spots form inside the solidified metal. These can be difficult to detect visually. Open shrinkage defects are exposed to the atmosphere and easily detectable due to their presence on the metal surface. The “pipe” type defect starts at the surface and burrows within the cast, while “caved surface” defects are scattered across the surface as hollow cavities. 

The severity of these defects requires a proper inspection method that can identify macro and micro defects present in the cast metal without error. NDT is an effective solution to identify these metal casting defects to ensure the safety and efficiency of the cast metal component.

Identifying Different Types of Defects in Cast Metals With NDT

Surface or internal metal casting defects can be identified with NDT technologies such as Eddy Current Testing (ECT) or Ultrasonic Testing (UT)

ECT can essentially replace Liquid Penetration Testing (LPT) and Magnetic Particle Testing (MPT) to be the most effective choice for identifying the surface or near-surface defects and casting irregularities. Eddy Current Array (ECA) probes and instruments can sense the change in the magnetic field induced within the cast metal, which indicates a flaw. This mechanism also enables technicians to use ECA for examining complex geometrical components. 

UT, however, is most commonly adopted by industries for its volumetric and accurate defect detection ability. As the ultrasonic wave-induced through the transducer within the cast metal is reflected back, the deflection of the wave can be analyzed to identify the presence of cracks, pores and voids, inclusions, and shrinkage defects. 

In addition, advanced UT instruments, probes and scanners can enable high-resolution A-scan displays, making it easier to distinguish and locate pores, grains, and other metal casting defects. The advanced NDT probes, instruments, and software make it possible to locate difficult-to-detect defects to ensure quality and meet standards for casting.

NDT Assessment of Metal Casting Defects for Quality Assurance

Meeting quality standards is the foremost priority of manufacturers. With a wide range of cast metals being used across industries, ensuring the quality of these cast components is crucial for safety and efficiency. With NDT, metal casting defects can be identified early in the process. Evaluation of flaws through NDT can help industries evaluate material integrity, safety, and thus, production excellence. 

Zetec provides advanced NDT solutions to facilitate your need to identify metal casting defects for a wide range of applications. To learn more, contact us today!