Magnetic flux leakage method of railway rails defects diagnostics and its place among mobile means of non-destructive testing

The task of mobile railway tracks defects diagnostics is to identify and recognize dangerous defects in order to prevent possible accidents. A review of the methods for controlling the physical and mechanical characteristics of metal constructions of engineering objects of long-term exploitation, which are used under different temperature regimes and conditions, is carried out in Among the described non-destructive methods on the used physical fields are allocated: magnetic, acoustic, electromagnetic, thermal and electrical. Electromagnetic methods are successfully used in various industries, such as the railway industry, the metal-working industry, the drilling, nuclear waste storage and so on. In particular, in the railway industry, using the technique of measuring the electromagnetic field of an alternating current, checks of carriages, wheel pairs and tracks are carried out. Recently, hybrid systems of diagnostics on the basis of carriages-defectoscopes are actively used to detect defects in railway tracks while simultaneously using magnetic, ultrasonic, visual-measuring and optical methods of non-destructive control. The high efficiency of new methods for constructing the information diagnostic system (IDS) of mobile magnetic railway tracks defectoscopy objectively depends on the successful solution of the certain contradiction: this is the provision of high resolution and sensitivity of IDS for the detection, differentiation and classification of the defects signals – on the one hand, and on the other hand – reduction of the time allocated for the defectoscopic examination in the conditions of various obstacles and the need for defects detection in the early stages of their development. Solving this contradiction with the use of modern methods of railway tracks defects signals processing and new small size multichannel and component sensors forms the content of an important application problem, which is considered in this article.