Titan №2 2014

MATERIALS SCIENCE

 

EFFECT OF VACUUM ION-PLASMA NITRIDING ON STRUCTURE AND PROPERTIES OF THE SURFACE IN TITANIUM ALUMUNIDE-BASED ALLOY

 

A. Mamonov, S. Sarychev, O. Umarova, A. Kozuyutov, I. Loboda

 

The effect of a low-temperature vacuum ion-plasma nitriding on phase composition, structure, microhardness and microgeometry of the surface and the depth of diffusion zone in Ti3Al-based alloy with initial bimodal structure has been studied. It has been shown that rise of temperature from 550 up to 650°С resulted in increase of Ti2N nitride amount in surface layer and formation of Ti3AlN nitride, which led to growth of microhardness, but diminished depth of strengthened diffusion zone; at the temperature of 650°С it caused formation of a great amount of pores on the surface. It has been stated that the formation of a nitrogen-modified surface layer in the alloy occurred mainly due to nitrogen diffusion in a fine-dispersed mixture of b- and secondary α(α2)-phases in bimodal structure of the alloy.

 

Keywords: titanium aluminide, vacuum ion-plasma nitriding, titanium nitride, microhardness, diffusion zone, structure.

 

FORMATION OF THERMALLY STABLE COMPOSITE STRUCTURES IN TITANIUM ALLOY WITH HIGH ALUMINUM CONTENT AT VACUUM ANNEALING

 

S. Skvortsova, V. Spektor, O. Gvozdeva, V. Pozhoga

 

The influence of vacuum annealing temperature on the formation of the phase composition and structure in titanium alloy with a high aluminum content pre-alloyed with 0.6 wt. % of hydrogen was studied. It is shown that if the vacuum annealing is carried out at temperatures where the extraction of the hydrogen atoms is faster than the diffusion of the basic alloying elements, it is possible to obtain in the alloy the structure uncharacteristic under equilibrium conditions but possessing high thermal stability in the temperature range of 600-750°С.

 

Keywords: titanium alloy, phase composition, structure, hydrogen, thermohydrogen treatment, thermal stability, heat resistance.

 

FRACTOGRAPHIC ANALYSIS OF OPERATING FAILURE A HIGH PRESSURE COMPRESSOR DISK OF ALLOY ВТ18У

 

M. Orlov, S. Naprienko, A. Lavrov

 

Operating failure a high pressure compressor disk of alloy ВТ18У was investigated by scanning electron microscopy method. Fragile mechanism of delayed fracture developing according to the crystallographic planes was determined. Mechanism of disk delayed fracture involving corrosive effects of aqueous saline, similar in composition to sea water was reconstructed by simulation conditions of static destruction of alloy ВТ18У samples.

 

Keywords: two-phase titanium alloy ВТ18У, compressor disk, delayed fracture, scanning electron microscopy, fractography, cracking.

 

 

Semi-products manufacturing technologies

 

TECHNOLOGICAL IMPROVEMENT OF MANUFACTURING TITANIUM NICKELIDE-BASED ALLOYS COUPLING FOR THERMOMECHANICAL JOINTS

 

M. Kollerov, D. Minaev, D. Chernov, S. Kuznetsov, A. Alexandrov, V. Lobastov

 

The possibility of technological development is considered to manufacture couplings made of TN1K alloy for thermomechanical joints of pipelines by the use of vacuum-induction method of ingots melting in cold crucible facility. It has been shown that the use of this method allows providing precision and homogeneity of the ingot composition, which is inherited by the structure and properties of deformed semis and pilot coupling batch.

 

Keywords: titanium nickelide, structure, properties, thermomechanical joint, coupling.

 

DEFORMATION PATTERN OF ALPHA-TITANIUM ALLOYS FOR PRODUCTION OF HOLLOW WORKPIECES WITH HIGHER DENCITY OF RADIAL TEXTURE

 

Yu. Loginov, A. Ershov

 

The analysis of the sources of information describing the process of the formation of texture in hollow workpieces made of alpha-titanium alloys. To improve the radial texture in titanium alloys having HCP lattice, is proposed to use a method for obtaining flat article, folding it into a ring blank and its pressure processing by methods of forging or rolling with wall thinning. It is shown that in such an occurrence persists additional strain compression, reducing the effectiveness of the influence of strain effects on the metal to develop radial texture. The calculations of the real dimensions of work piece linear model depending on the parameter Kearns from deformation parameters. An alternative scheme manufacture hollow billets of alpha titanium alloys improves radial Kearns parameter.

 

Keywords: titanium, deformation, rolling, Kearns parameters.

 

 

Semi-products treatment technologies

 

TECHNOLOGICAL PARAMETERS DETERMINATION FOR PILOT HIGH-TEMPERATURE Ti2AlNb-BASE ALLOY DEFORMATION PROCESS

 

E. Alexeev, N. Nochovnaya, S. Skvortsova, P. Panin, O. Umarova

 

The article contains the results of applied research on determination of technological parameters of a pilot high-temperature ortho-alloy Ti-13Al-40Nb-5(Zr+V+Mo+W)-0.5(Si+C) deformation. It was determined the maximal degree of deformation for the alloy was 75 percent upon upsetting at temperatures higher than 1000°С. It was established a temperature of 950°С for pilot alloy was the temperature of hot working process at which strain hardening effect was not observed. It was also shown a temperature of 900°С was the minimal temperature that provides a defect-free sample surface formation during upsetting, and the maximal degree of deformation was 71 percent at this temperature. The tests at lower temperatures result in defects and cracks appearance.

 

Keywords: high-temperature titanium ortho-alloy, isothermal deformation, acceptable limit of deformation amount, upsetting, strain strengthening, hot pressure working.

 

 

Titanium market

 

CONVERSION FROM RUSSIAN TO INTERNATIONAL ACCOUNTING STANDARDS (CASE OF FIXED ASSETS ACCOUNTING AND STAFF REMUNERATION ACCOUNTING)

 

A. Alexakhin, L. Kostigova, A. Zolkina, N. Lomonosova

 

Changes in the list of major items of accounting rules and requirements of international financial reporting standards (particularly, methodology of staff remuneration calculation and fixed assets accounting) justify timeliness and high practical significance of this study. Comparative analysis of Russian accounting system and international accounting system allows to take into account the special features of reporting calculation on the large industrial enterprises of RF.

 

Keywords: accounting, remuneration, social insurance, fixed assets, depreciation.

 

ABOUT THE PLACE OF HYDROGEN TECHNOLOGY OF TITANIUM ALLOYS IN STRUCTURE OF THE SIXTH TECHNOLOGICAL MODE

 

Ju. Kusakina, L. Fedorova, G. Gurtovaya, T. Yagudin

 

The place of hydrogen technology is analyzed which can be used as alternative power engineering for the creation of materials with in advance specific properties or at the processing of the secondary titanium. This technology is innovative for the majority of bearing branches of the sixth technological mode for aerospace and defensive, chemical, medical, metallurgical branches.

 

Keywords: hydrogen technology of titanium alloys, technological mode, bearing branches of technological mode.

 

 

Events and anniversaries

 

To the 75-year anniversary Yuri Kudryavtsev

 

 

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