Faculty: Mechanical
Speciality: Technology of machine-building
Scientific adviser: |
Mykhailov Alexander |
Upgrading quality for process of shoulder-blades manufacturing for guide vanes of GTE.
The analysis of gas-turbines engine (GTE) in the process of exploitation shows, that most damages of details carries tireless character, it is therefore difficult to over-estimate the practical value a problem of providing their bearing strength.
Prognostication of bearing strength details of GTE which having a difficult form, different character of loading and condition of exploitation, is an intricate problem.
Most complete picture of bearing strength details of GTE is possible to get by families of curves of fatigue, which answering required probabilities of destruction. Tests of plenty of such details of GTE, as billows and disks, attended with difficulties and high cost. In most cases it is succeeded to conduct the tests of laboratory standards from materials details of GTE in terms only approaching operating.
For judgment about bearing strength of details from these data it is necessary to search new methods, which with sufficient authenticity would repulsed influence on resistance of fatigue of geometrical sizes, technology of making and physico-mechanical descriptions of materials.
Shoulder-blades, billows and disks, are the most loaded and difficultly processed details of modern GTE. On these details are influence the variable and centrifugal loadings, additional loadings from high-frequency vibrations at presence of corrosive environment and high temperatures in the process of work engine. On the shoulder-blades exploited in unfavorable terms, erosion develops and the mechanical damages.
Terms of work of these details compels to materials and properties of superficial layer high requirements.
The origin of fatigue crack is usually begun with a surface because here are most cyclic tensions at a bend, concentration of tensions and different defects of surface. Therefore quality surface of details GTE has considerable influence on resistance of fatigue. Degree of influencing roughness and remaining tensions on resistance of fatigue details it is possible with certain probability to expect by statistical methods.
For the increase of bearing strength of details GTE and declines the methods of superficial plastic deformation (SPD), allowing regulating properties of superficial layer, are widely used in industry.
Changing the modes of superficial plastic deformation, it is possible to manage the parameters of roughness and remaining tensions taking into account the structure of material, scale factor and concentration of tensions.
For finish processing of billows, shoulder-blades and disks GTE more wide application is found by such methods of SPD as the diamond pressing, ultrasonic consolidating by marbles and other.
Scientific meaningfulness consists in establishment of conformities to the law between operations of technological process of treatment shoulder-blades gas-turbine engine, creation of rational structure of technological process of treatment shoulder-blades of gas-turbine engine.
Practical meaningfulness consists in longevity rises at upgrading shoulder-blades for guide vanes of gas-turbine engine, wearproofness and, accordingly, term of exploitation of shoulder-blades.
Work of vybro plant for finish abrasive treatment
of details is based on principle of the use an unstable
forces, which are created through the loads fastened on
the ends of billow of vibrator.
Greater part of vybro treatment is executed on vybro plant with a horizontal billow and container of U-vivid form. Vybro plant of this type due to the capacious container of rectangular section in a plan allows conducting treatment of middle and large details and differing by simplicity of form of container. However much these options have a sense to formation of areas of uneven treatment at end walls, differ by high energy expense. Vibro plant with a vertical billow and round container is deprived these failings.
On an enterprise «Motor Sich» 160 units of vybro plant are exploited for treatment the more than 7 thousand names of details, such as disks, billows, gear-wheels, shoulder-blades.
Shoulder-blades are the characteristic mass details of aviation GTE, work in the conditions of the high static, dynamic and thermal loadings and in a great deal determine a resource and
reliability of work of engine on the whole.
For their making are used titanic, heatproof alloys on the basis of nickel, and also compositions materials.
The labour intensiveness of making of shoulder-blades in most constructions of GTE is 30-40 % general labour intensiveness of engine. This feature, along with the terms of work of shoulder-blade in an engine, requires the uses in production of progressive methods for receipt of purveyances, modern technologies of treatment, especially on finishes operations mechanization and automation of technological processes.
In aviation turbines a guide vanes usually is the easy welded construction from heat-resistant steel. The also poured nozzles crowns are used from heat-resistant alloys and demountable vehicles with the separate shoulder-blades, inserted in the corps of turbine or in rings is outward and internal, limiting sending the vehicle of turbine. On image 1 shoulder-blades inserted in an internal ring. Sending shoulder-blades cool down by the air given from one of stages of compressor.
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Image 1 — Guide vanes of gas-turbine engine. |
Large value in the decision of problem of providing of resource and reliability of aviation GTE, and also creations of engines of new generations are had by development, perfection and creation of new technological processes, methods of treatment of details and equipment, which promote not only productivity but also quality of making.
Vybro plant applies on operations: vybro polishing, vybro buffing, cleaning of details from dross, corrosion, removal of burr and dulling of sharp edges on details. For the large shoulder-blades of GTE use the method of longitudinal single vybro treatment in the reserved container is used.
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