How to Detect Damage in Crane Wheels

The crane wheel is a component that is relatively prone to damage. Based on its operating characteristics, the wheel tread must have high hardness and a certain depth of hardened layer and transition zone (depth >10mm, hardness HRC 40–48) to enhance load-bearing capacity, wear resistance, and contact fatigue resistance. The base material should have excellent comprehensive mechanical properties and a good structural state, with a hardness of HBS 187–229, ensuring high toughness to improve impact resistance and crack resistance.

So how can we detect whether a crane wheel is damaged?

Nondestructive testing (NDT) is performed directly on the crane wheel and can accurately reveal internal or surface defects. The main NDT methods currently used for crane wheels include magnetic particle testing, penetrant testing, ultrasonic testing, and X-ray testing.

1. Magnetic Particle Testing
   This is a surface inspection method. It works by magnetizing the crane wheel forging using magnetic flux. Cracks in the forging create magnetic poles, and when dry or wet magnetic particles are applied, they gather at the defect locations, making the flaws visible. This method requires a smooth surface with a surface roughness (Ra) not exceeding 1.6μm.

2. Penetrant Testing
   Also used for surface inspection, penetrant testing is suitable for non-ferromagnetic materials and is not limited by the magnetic properties of the material. A penetrant seeps into surface defects, and a developer draws it out so the flaws become visible to the naked eye under normal light. For non-ferromagnetic materials, fluorescent penetrant testing can be used — fluorescent dye enters the defects and is made visible under ultraviolet light. This method works regardless of whether the material is magnetic or not.

3. Ultrasonic Testing
   This is used to detect internal defects. An ultrasonic detector emits high-frequency sound waves (0.5–10 MHz) into the crane wheel forging. These ultrasonic waves cannot pass through solid-gas interfaces. If the forging has no defects, the waves reflect back uniformly, producing a standard signal on the display. If there are internal flaws, the waves reflect irregularly at the defect site, and the display shows abnormal signals. This allows inspectors to determine the location and size of the defect.

4. X-ray Testing
   X-ray testing is based on the principle that materials with different chemical compositions absorb X-rays to different extents. Air absorbs far less than metal. In a darkroom, X-rays are projected through the forging onto a special screen (similar to a medical X-ray). Cracks let through more radiation, creating brighter areas on the screen. This method is suitable for steel forgings up to 120mm thick and aluminum forgings up to 600mm thick.

   
   

To ensure high-quality crane wheels, it is essential to choose a professional manufacturer. Ma'anshan Tianjun Machinery Manufacturing Co., Ltd. has extensive forging experience and adheres to the principles of integrity, diligence, and customer service. The company remains at the forefront of the forging industry. With innovative R&D capabilities and strict quality control, we ensure that every product meets international standards, providing reliable support for railway and industrial transportation worldwide.

For more information about train wheels or to request a quote, please contact us!