[en] The present paper explores the effect of annealing on mechanical and structural properties of ultrafine-grained (UFG) Ti Grade 2 after it was mechanically worked in either CONFORM SPD or rotary swaging (RS) machine. The main objective of this study was to optimize the annealing schedule in order to achieve recovery in the severely deformed structure and at the same time retain the mechanical properties of the worked material. The temperatures of the recovery processes were determined by means of dilatometry. It was found that in an ultrafine-grained material the temperatures of the recovery processes are shifted towards lower values. Based on dilatometric analysis, annealing schedules were developed and mechanical and structural properties were evaluated. (paper)

[en] Molybdenum monocrystal texture with crystallographic orientations of rod axes (112) and (100) after deformation in the range from 0 to 97% is investigated. A texture resulting from rotary swaging of molybdenum polycrystal rod with the same degrees of deformation is simultaneously studied. It is shown that the character of texture formation is different during rotary swaging of molybdenum monocrystals and polycrystals. For monocrystals it depends on the initial orientation. During rotary swaging of molybdenum polycrystal rod the total axial texture formation is observed under all deformation degrees, whereas in case of monocrystals under deformation more than 70%

[en] The process of drop forging is considered, which includes five blows. The change of the force is shown along during the drop forging of the disc made of heat resistant EhP742 alloy using a hydraulic press with the force of 30000 f. It is found out that pressing permits to decrease considerably energy consumptions mainly at the expense of the excluding additional heatings of articles, and to uduce the technological cycle of pressing, to decrease its labour-consumption

[en] In this study, compound plastic deformation technologies including canned extrusion and rotary swaging were developed to produce W-40 wt.% Cu composite. The relative density increases from 98.4% of as-extruded composite to 99.1% after swaging at 1223 K. The as-extruded composites have conductance of 67% IACS and hardness of 155 HV. But the as-extruded composites swaged at 1173 K ∼ 1323 K have higher hardness and lower specific conductance with accumulated deformation amount ∼72.30%. After heat treatment at 973 K ∼ 1273 K, the deformed material obtained a better match between the hardness and the conductivity. After compound plastic deformation, homogeneous microstructure of W and Cu phases for W-40 wt.% Cu composite can be acquired. All results indicate that W-40 wt.% Cu composite with high performance can be fabricated by compound plastic deformation technologies. (paper)

[en] This invention has a use in metallurgy, particularly in the making of components forming part of pipe holding rings for nuclear reactors. An orifice, centred on the axis of the pipe to be obtained, is made in the wall of a pressure vessel more than 100 mm thick. The plate is heated in the area around the orifice to a temperature between that corresponding to the A₃ transformation point and that corresponding to the forging temperature. A circular mono-dimensional pull is applied at the orifice area with hollowing, after which the ensemble achieved is given a set, without compressing it, so as to impart a definitive shape to it

[en] An Advanced Research Reactor(ARR) is being designed by KAERI since 2002. The final goal of the project is to develop a new and unique research reactor model which is superior in safety and economical aspects. In this work, the conceptual design for tubular fuel assemblies was carried out to enhance the previous model. The shape optimization of the cross section of the top guide was performed, and the swaging procedure in connecting fuel plates and stiffeners was developed. Moreover to reflect changes in number and size of fuel plates, related parts of the standard and the reduced fuel assemblies were redesigned. The top guide should suppress the vibration of the fuel assembly due to coolant and resist against material failures owing to fatigue and yield. In order to gain these design requirements, we have optimized the section profile of the top guide. To confirm manufacturing aspects, the swaging procedure was developed and its performance was tested. The results of tangential tensile test and axial compression test guaranteed that the fixing state between fuel plates and stiffeners is firm enough to hold each other. In addition, due to changes in number and size of fuel plates, the outer cross section of the fuel assembly was expanded and the diameter of the spacer tube was reduced. Reflecting these design changes, top/bottom guide, top guide cover, spring, spring cover, and receptacle were readjusted. Based on the technical experiences on the design and operation of the HANARO, the standard and the reduced fuel assemblies will be verified by performing various tests and analysis

No abstract available

[en] The tube work piece is working in vertiginate gas flow, so strict processing consistency is required in its dimension and shape which are mainly acquired by rotary swaging process. In the analysis of this process, the real forging frequency, the max work piece feed speed, and the die displacement model are established. As well as the 3D simulation of rotary swaging process is given by DEFORM-3D, the effects of different feed velocity and friction coefficient are discussed. The analysis can be used as an important reference for the improvement of rotary swaging equipment and process. (author)

[en] Thermo-hydraulic problems, in nuclear plants are normally analysed by using electrically heated rods. Carbon/carbon composites were used to make heating elements for testing by indirect heating up to a heat flux of 100 W/cm². It is easy to verify that this value can be exceed if the choice of the complementary materials for insulator and cladding were improved. The swaging process used to reduce the cladding diameter prevented the fabrication of graphite heater rods. (author)

[en] Quite often the W-Ni-Fe-Co heavy alloys are subjected to a thermomechanical processing of swaging and aging in order to obtain the highest possible level of resistance. Within the framework of this plastic deformation on cylindrical parts, the swaging leads to the distribution of morphological and crystallographic texture as well as specific internal stresses. The resulting mechanical characteristics are correlated to structural and sub-structural variations. (author)