The investigation results of metal surface processing before industrial painting or protective coat application are shown. A pre-coloring processing defines quality of the coating applied, its adhesion with basic metal, uniformity and strength. The processes of surface roughness formation depending on processing modes and properties of the abrasive used are considered thoroughly.

The efficient and durable coloration of cars at their manufacturing and repair needs preparation of surfaces to be painted which consists in ensuring their quality and forming proper roughness required for painting and degreasing. The paper reports the standard method offered for the assessment of technical and economical efficiency of railroad car metal surface processing with a free abrasive based on data of processing modes, materials used and quality of a clean surface obtained. For this at the initial stage there was carried out the analysis of standards in the field of a metal pre-coloration processing for the purpose of the require-ments to the quality of a surface to be clean, roughness and a degree of degreasing. In the corresponding stand-ards there are defined three basic groups of surface preparation quality, which may be conditionally subdi-vided into high, average and low quality. The assess-ment of processing efficiency was carried out under a condition of ensuring the first quality group. For that there was carried out a comparison of four standard technologies of metal pre-painting for the purpose of the process efficiency, material consumption (power) and surface processing quality obtained. The comparison has shown that the highest effectiveness has a technology of thermal abrasive-jet processing. This technology allows avoiding chemical agents use for metal surface degreasing which allows decreasing material capacity of the process and increasing considera-bly a pre-painting productivity.

The assessment of metal surface preliminary processing effectiveness before coloration is an urgent scientific-practical problem. In the paper there is shown a comparison of technical and economic characteristics of standard methods of metal pre-coloration processing by the example of steel railway car cleaning. The assessment is carried out according to the criteria of effectiveness and processing quality, amount of scrap collected, material capacity and so on.

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The study objective is to increase the productivity of restoring rail profiles. The paper is devoted to the solution of the problem to determine thermal force, vibro-acoustic and energy parameters of milling machining of rail steel in various conditions. The computational and analytical method of research, express diagnostics are used. The novelty is in the proposed improved technology of rail reprofiling. The following results are obtained: it is found that the most productive and effective method of rail reprofiling in stationary conditions is milling on special rail milling machines; the main directions of increasing the machinability of rail steel are determined, which allows the development of induction heating technology for softening the surface defective metal layer of the rail head. Conclusion: the range of rational cutting modes of rail steel with thermal annealing are found.