On the Possibility of In-Process Magnetic Detection of Flaws in Rails

Abstract

A procedure has been developed to detect surface defects in the head and foot of a rail using a magnetic method involving thin-film magnetoresistive field sensors. The setup consists of a system for moving the rail in the longitudinal direction, a magnetizing solenoid, cartridges with field sensors for inspecting the rail head and foot, a DC electromagnet with attached pole pieces, and a “robotic” transverse movement unit with an additional cartridge for revealing long-sized defects (over the entire length of the rail). The electrical signals of the sensors are transmitted to an analog-to-digital converter and processed digitally. The possibility of detecting all surface defects stipulated by the regulatory and technical documentation of JSC Russian Railways is demonstrated.