Repair technology features of main elements of road-building machines’ hydraulic system with use of polymer composite materials

Features of the operation and typical damages of standard hydraulic systems’ elements of road-building machines have been analyzed. The occurrence reasons of defects and the elimination ways of them were determined. Methods for eliminating the defects were analyzed, and it is shown that one of the most promising methods for eliminating the defects in liners of hydraulic cylinders and hydraulic lines is the use of polymer composite materials with a fibrous or dispersed filler for the repair.

Analytical Model and Numerical Analysis of Composite Wrap System Applied to Steel Pipeline

Composite overwraps are a cost-effective repair technology, appropriate for corrosion defects, dents, and gouges for both onshore and offshore steel pipelines. The main benefit of polymer-based sleeves is safe installation without taking the pipeline out of service. This paper presents a new calculation procedure proposed in the form of an algorithm for the sizing of composite repairs of corroded pipelines when the sleeve is applied at zero internal pressure. The main objective of the presented methodology is determination of the effective thickness of the composite repair without its overestimation or underestimation. The authors used a non-linear finite element method with constitutive models allowing analysis of the steel, putty, and composite structures. The validation of the results of numerical computations compared to the experimental ones showed an appropriate agreement. The numerical calculations were applied to compare the analytical results in relation to those obtained by the standards ASME PCC-2 or ISO/TS 24817. The comparison showed that the proposed solution confirmed its effectiveness in reducing the thickness of the sleeve significantly, thus, showing that the current industrial standards provide a considerably excessive composite wrap around the steel pipe corroded area, which leads to an unnecessary increase in the repair costs.

Modern concepts of refractory materials application in production of steel and cast iron

Refractory lining is an integral part of metallurgical facilities and requires constant perfection. Examples of successful interaction of specialists-steelmakers, companies-manufacturers of refractories and engineering companies on increasing efficiency of refractories application in steel industry presented. The wide application of drying and heating stations of steel ladles, EAFs, BOFs was noted because of using refractory gunned castable at their current repairs. The growth of unmolded refractory share in the BF production was shown. At the stoves repair technology of guniting and shotcreting is widely used. Transfer to application of modern concrete at lining of shoots, ramming mixtures and repairs with application of liquid concrete addition resulted in a decrease of labor­ intensiveness of repair work, accelerated the process of repair and considerably decreased specific consumption of refractory materi­als. Nevertheless, within a predictable period, despite of increase of unmolded refractories application, it is expected that the molded refractories would take the main share of the refractory market in the steelmaking. Creation of partial load conditions in a metallurgical facility is an important factor for increasing lining resistivity. Slag foaming in EAF screens radiation from electrodes in the process of the furnace running. Blowing of the final slag (preliminary enriched by magnesium oxide in case of necessity) forms a scull on the working surface of the BOF lining, thus preventing intensive contact of the refractory lining with steel melt and slag. Modem technologies of instrumental control the lining state of metallurgical facility within the period of its running considered, which allowto accomplish operation of hot repair at particular arears of the lining, avoiding overconsumption of the repair material. It was noted that apart from the task of decreasing specific expenses for refractory materials, the customers most often estimate the indirect costs, cover of loss and obtaining additional profit due to increase of metal production because of increase of overhaul period and decrease of time of lining repair. This is the purpose of cooperation of specialists of refractories manufacturers and metallurgical plants.

Development of a Methodological Base for Assessing the Validity of Choice of an Outsourcing Organization in JSC «Russian Railways»

The issues of methodological support of interaction between a large transport company and its general contractors are becoming more significant due to the increasing number of types of activities transferred to outsourcing. The article investigated the main methodological approaches that determine the procedure for justifying the choice of an outsourcing organization and the relevant methods applied in practice, in particular, an assessment of the methodological basis for judging the effectiveness of the choice of infrastructure repair workflow was carried out. The analysis of the methods for justifying the choice of a third-party organization, performing railway infrastructure repair work, made it possible to form the author's methodological approach to the choice of a repair technology and an organization to perform it best on outsourcing basis. The specifics of the object, namely, JSC «Russian Railways», which provides strategically important services for the economy, allows us to recommend the proposed author's methodological approach to justifying the choice of a third-party organization performing work for other transport companies.