Abstract
Railway is an important transportation in the world and its safety is highly valued. The wheels and axles are key components on locomotives and rolling stocks in China railway, so the failure of the wheel or axle may lead to severe accident, especially in high speed or heavy haul application. To avoid train accident, daily check and regular inspection are necessary. The surface condition of wheel and axle, parameter of wheel such as diameter and wheel profile can be checked by train operator using eye or instrument. Magnetic particle testing is used regularly to find the surface defect generated during wheel and axle application. For detecting inner defects of wheel and axle, such as material defects or cracks, ultrasonic inspection is applied usually on production line during manufacturing, and different ultrasonic inspection methods and equipment are also applied regularly to find the defects in different checking maintenance levels to ensure the safety of train operation. Now, the condition of all the CRH wheel and axle is under monitor and control. The similar wheel and axle safety guarantee system is under construction for Chinese heavy haul locomotives.
