Railway locomotive and carriage wheels are vital components for the safe operation of trains, serving both load-bearing and guiding functions. If a wheel malfunctions, it can lead to wheel breakage, axle failure, or even major derailments. Therefore, ensuring the proper inspection and safe operation of wheels is critical.

·Main Hazardous Defects in Railway Locomotive and Carriage Wheels

1. Rim Cracking

During train operation, the area beneath the wheel's contact surface (at a depth of 10 mm to 20 mm) is where the maximum shear stress from wheel-rail contact is concentrated. If non-metallic inclusions or other metallurgical defects exist in this region, these inclusions can become sources of fatigue cracks under the influence of shear stress, causing the cracks to propagate. The shear stress from wheel-rail contact is inherent to train operation, and once a crack source is initiated, the crack expands faster as the train speed increases. As the crack grows and reaches a larger size in the rapid expansion phase, it can propagate to the outer or inner rim or tread. If not detected in time, this could result in the wheel "chipping." This defect is known as rim cracking.

Rim cracking defects exhibit clear fatigue origins and a fatigue propagation process (shell-like cracks). The development of rim cracks follows a circular direction along the wheel, which is why it is referred to as a circumferential defect.

2. Wheel Fracture Damage

Wheel fractures can occur due to severe braking, internal metallurgical defects, or manufacturing flaws, leading to radial cracking of the wheel. This can cause derailments during train operation. Radial fractures develop along the wheel's diameter, which is why this is referred to as a radial defect.

·Ultrasonic Testing for Wheel Defects

1. Detection of Circumferential Cracks

Ultrasonic testing works on the principle that maximum reflection occurs when sound waves are perpendicular to the crack surface. When ultrasonic waves are incident radially into the wheel, they are perfectly perpendicular to circumferential defects. Thus, ultrasonic radial incidence is used to detect circumferential defects in the wheel.

2. Detection of Radial Defects

Conventional ultrasonic shear waves are used to detect radial defects in the wheel.

Tianjun Machinery, established in 2005, is primarily dedicated to the production and research and development of railway products, including train wheels, axles, wheel rims, and wheelsets. We have extensive experience in exporting railway wheels and have exported train wheels to numerous countries, including Germany, the United States, South Africa, Mexico, Turkey, India, the Netherlands, Kenya, Algeria, Mauritania, Iran, Brazil, Australia, Bangladesh, Ethiopia, and many more.

For inquiries, please contact tj-marketing@tj-wheel.com.