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Advanced NDT Techniques for Detecting Hidden Corrosion in Structures

Table of Contents

  • Introduction
  • Common Causes of Hidden Corrosion
  • Advanced NDT Techniques for Detecting Hidden Corrosion
  • Benefits of Using Advanced NDT Techniques
  • Conclusion


Within the structures like bridges, pipelines, and industrial machinery, a silent threat lies in wait. It’s corrosion, a stealthy enemy that weakens materials from within, posing a danger that’s often unseen until it’s too late. Well, there are armed guardians, Non-Destructive Testing (NDT) techniques. NDT techniques for detecting hidden corrosion in structures allow us to uncover hidden corrosion, safeguarding against potential disasters.

Common Causes of Hidden Corrosion

Common Causes of Hidden Corrosion include poor coating application, inadequate inspection protocols, and exposure to corrosive environments. Implementing regular inspections, utilising advanced non-destructive testing methods, and ensuring proper coating maintenance are essential in detecting and preventing hidden corrosion. Several factors contribute to the development of hidden corrosion.

  1. Exposure to Corrosive Environments: Structures exposed to harsh environmental conditions, such as coastal areas with high humidity or industrial facilities with chemical pollutants, are more prone to hidden corrosion. The presence of corrosive agents accelerates the degradation of materials, even when they are coated or protected.

2. Lack of Proper Maintenance: Inadequate maintenance practices, including infrequent inspections or failure to address surface damage promptly, can exacerbate hidden corrosion. Without regular monitoring and upkeep, corrosion may go unnoticed until it has caused significant structural damage.

3. Inadequate Coating Protection: Protective coatings play a crucial role in preventing corrosion by forming a barrier between the underlying material and corrosive elements. However, if coatings are improperly applied, damaged, or degrade over time, they may fail to provide adequate protection, leaving the underlying material vulnerable to hidden corrosion.

4. Moisture Infiltration: Moisture is a primary catalyst for corrosion, as it facilitates the electrochemical reactions responsible for metal degradation. Inaccessible areas within structures, such as crevices, joints, or enclosed spaces, can trap moisture, creating ideal conditions for hidden corrosion to occur.

5. Chemical Exposure: Exposure to corrosive chemicals, such as acids, salts, or pollutants, can accelerate the corrosion process, particularly in concealed areas where ventilation is limited. Chemical reactions between the corrosive agents and metal surfaces can lead to rapid deterioration, compromising structural integrity.

6. Fluctuating Temperatures: Temperature fluctuations, especially in environments with high humidity or extreme heat, can exacerbate hidden corrosion by promoting the expansion and contraction of materials. Thermal cycling can cause protective coatings to crack or degrade, exposing underlying surfaces to corrosive elements.

Advanced NDT Techniques for Detecting Hidden Corrosion

Non-destructive testing techniques has revolutionised corrosion testing methods and corrosion mapping the way industries inspect materials without causing damage. In particular, advanced NDT techniques like Phased Array Ultrasonic Testing (PAUT), and Eddy Current Array (ECA) Testing have emerged as powerful tools for detecting hidden corrosion, ensuring structural integrity, and enhancing safety standards across various sectors.

1. X-Ray

How X-Ray Works

X-rays pass through materials and are absorbed or scattered based on density and thickness. The resulting radiograph reveals density variations, including defects like corrosion.

Advantages of X-Ray

X-rays offer high-resolution imaging, versatile applications across industries, and non-destructive properties, enabling inspections of dense materials, complex structures, and defects without damage.

Applications of X-Ray

The aerospace industry, automotive sector, industrial manufacturing, and infrastructure inspection all involve assessing structural integrity and evaluating components for hidden corrosion.

2. Phased Array Ultrasonic Testing (PAUT)

How PAUT Works

PAUT employs advanced ultrasonic technology to inspect materials for hidden corrosion. By emitting multiple ultrasonic beams at various angles, PAUT can accurately map the thickness and integrity of structural components, identifying areas of corrosion or degradation with precision.

Advantages of PAUT

PAUT offers numerous advantages over traditional ultrasonic testing methods. Its ability to provide detailed images of internal structures, coupled with faster inspection times and improved sensitivity, makes it an indispensable tool for detecting hidden corrosion in critical components.

Applications of PAUT

PAUT finds widespread applications in industries such as aerospace, automotive, oil and gas, and manufacturing, where the detection of hidden corrosion is crucial for ensuring structural integrity and preventing catastrophic failures.

3. Eddy Current Array (ECA) Testing

How ECA Testing Works

ECA Testing relies on electromagnetic principles to detect hidden corrosion in conductive materials. By inducing electrical currents in the material, ECA can identify changes in conductivity caused by corrosion, providing detailed insights into the extent and severity of damage.

Advantages of ECA Testing

ECA testing offers advantages such as high inspection speed, enhanced sensitivity to surface-breaking defects, and the ability to inspect complex geometries, making it a preferred choice for detecting hidden corrosion in critical components.

Applications of ECA Testing

ECA testing is extensively used in industries such as aerospace, automotive manufacturing, power generation, and infrastructure, where the detection of hidden corrosion is essential for ensuring the safety and reliability of assets.

Advancements in sensor technology, data analytics, and artificial intelligence are driving innovation in NDT, leading to the development of smarter, more efficient inspection systems. Emerging trends such as robotics, remote monitoring, and augmented reality are reshaping the landscape of NDT, enabling safer, more reliable inspections in challenging environments.

Trust NDT Products for all your non-destructive testing needs and experience unparalleled performance, durability, and peace of mind with every inspection.

Benefits of Using Advanced NDT Techniques

Benefits of using advanced NDT techniques include increased accuracy, efficiency, and cost-effectiveness in detecting defects and abnormalities in critical infrastructure. Additionally, these techniques can provide valuable data for predictive maintenance, ultimately extending the lifespan of assets and reducing overall operational costs. A few of the advantages are discussed below.

Early Detection of Corrosion Damage

Advanced NDT techniques offer early detection capabilities, allowing inspectors to identify corrosion damage in its early stages before it progresses to critical levels. This proactive approach enables timely interventions to prevent further deterioration and mitigate potential risks.

Reduced Maintenance Costs

By detecting hidden corrosion early on, advanced NDT techniques help minimise maintenance costs associated with repairing or replacing damaged structural components. Timely interventions can extend the service life of assets and reduce the need for costly repairs or replacements.

Enhanced Safety and Structural Integrity

Detecting and addressing hidden corrosion contributes to the overall safety and structural integrity of buildings, bridges, pipelines, and other infrastructure. By identifying structural vulnerabilities and addressing them promptly, advanced NDT techniques help mitigate the risk of catastrophic failures and ensure the longevity of assets.


Hidden corrosion is a significant issue in various industries, posing threats to structural integrity and safety. It occurs beneath protective coatings or in inaccessible areas, making it difficult to detect until significant damage has occurred. Embracing advanced NDT methods enhances safety, structural integrity, and asset longevity.

NDT Products is known for delivering top-notch non-destructive testing solutions that exceed industry standards. With an extensive range of high-quality products and unmatched expertise, we cater to the diverse needs of clients across various sectors, from aerospace and automotive to oil and gas.