Eddy Current Flaw Detectors for Rail Testing

Intensive rail traffic and high axle loads, particularly on mainlines, heavy-haul routes, and high-speed lines, cause significant contact stress between the wheel and rail. This leads to rolling contact fatigue in the rail metal, which can result in surface and subsurface defects in the rail head, such as head checks and squats. These defects are hazardous because they quickly progress to a critical stage, increasing the risk of sudden rail fracture.

Eddy current rail flaw detectors are an effective solution for detecting surface cracks and subsurface discontinuities in the rail head at an early stage of development, as well as determining the depth of damage, enabling timely decisions on grinding or rail replacement. Additionally, eddy current inspection equipment can be utilized in conjunction with ultrasonic flaw detectors, enhancing the overall reliability of rail defect detection.

Operating Principles of Eddy Current Rail Flaw Detectors

Eddy current rail flaw detectors operate by generating an alternating electromagnetic field within the inspection probe. As the probe moves along the rail surface, it induces eddy currents on its surface. Any disruption in the structure of the material, such as a crack or other discontinuity, changes the distribution of these currents and alters the signal from the probe. By analyzing these signal variations, the eddy current flaw detector can accurately detect and locate surface and subsurface defects in the rail head, as well as assess their depth.

The OKOndt Group's range of eddy current rail testing equipment

• High-speed systems. Designed for installation on inspection trains, self-propelled inspection cars, and hi-rail vehicles. The equipment enables NDT inspectors to inspect rails continuously, without disrupting regular rail traffic. Hi-rail vehicles are considered the most cost-effective solution for routine track inspection.
• Hand-pushed rail flaw detectors. Designed for eddy current rail inspection. They verify the results of rail testing performed by high-speed systems and can perform NDT rail inspections of short regional track sections and industrial lines independently.

See also: Ultrasonic flaw detectors for detecting internal and surface defects in rails

Eddy Current Rail Inspection Solutions from OKOndt GROUP

OKOndt GROUP manufactures eddy current rail flaw detection systems and develops customized railway NDT solutions for service companies and technicians responsible for rail track inspection and quality assurance during rail production. Please complete the inquiry form on our website to determine which type of eddy current testing equipment best suits your railroad infrastructure and inspection tasks. Our specialists will review your requirements and recommend the most appropriate solution for your needs.