Contribution of Hardening Mechanism to VVER-1000 RPV Welds Flux Effect

Systematic differences in the radiation embrittlement kinetics of steels irradiated with different fluxes requires a clear understanding and assessment of the mechanisms responsible for the flux effect. This paper presents results of research of hardening mechanism contribution to flux effect of VVER-1000 reactor pressure vessel (RPV) welds. Transmission electron microscopy (TEM) and atom probe tomography (APT) investigations were carried out. Studies of hardening phases of RPV-steel (VVER-1000) after accelerated irradiation allowed to estimate the contribution of the hardening mechanism to flux effect. Keywords: reactor pressure vessel, hardening mechanism, flux effec

Comparative Evaluation of Custom-Made Components and Standard Implants for Acetabular Reconstruction in Revision Total Hip Arthroplasty

Background.The use of custom-made acetabular components is one of the promising methods for reconstruction of the acetabulum in cases of significant defects, including those associated with pelvic bone dissociation. It allows achieving stable fixation and restoring the biomechanics of the hip joint. Aimofthestudy to compare the results of using individually designed components, supportive antiprotrusion rings, augments, and hemispherical components in revision total hip arthroplasty for type IIIB bone defects according to Paprosky classification. Methods.The study analyzed the treatment outcomes of 90 patients with type IIIB bone defects who underwent revision total hip arthroplasty between 2017 and 2022. Patients were divided into three groups: the first group received individually designed acetabular components, the second group received augments with hemispheres, and the third group had antiprotrusion cages implanted. The analysis included the reasons for revision surgery, operation duration, blood loss volume, and type of revision procedure. Pain and functional outcomes were assessed with WOMAC, Harris Hip Score, and VAS scales. Results.3D-printed constructs were more frequently implanted in patients with pelvic bone dissociation. The first group showed a significantly positive dynamic in functional outcomes. Complications were diagnosed in 27 (30%) cases: joint instability (dislocation) in 10 (11.1%) patients, periprosthetic infection in 8 (8.8%), aseptic loosening in 4 (4.4%), and sciatic nerve neuropathy in 5 (5.5%) patients. The number of these complications was higher in the second and third groups of patients. Conclusion.Custom-made implants using 3D technologies are a preferable option for revision total hip arthroplasty in patients with type IIIB defects according to Paprosky classification, especially in cases of pelvic bone dissociation

First tidal disruption events discovered by SRG/eROSITA: X-ray/optical properties and X-ray luminosity function at z < 0.6

High Energy Astrophysic

UNTRADITIONAL APPROACHES TO THE DEVELOPMENT OF SECTION ROLLING PRODUCTION

The conception of section rolling production of new formation, taking into account both the taken earlier and confirmed by practice technological decisions and new requirements, is considered

Continuous grade rolling. Trends and perspectives of development of technology and equipmen

There are examined the different technological processes of endless rolling, stipulating for jump welding of slugs into endless string and direct alignment of the processes of continuous casting of slugs and rolling. There are marked the successes of foreign firms on using of the process of endless rolling in the foundry-rolling units

CREATION OF INFORMATION-ANALYTICAL SYSTEM OF CONTINUOUS GRADED ROLLING

The computer means allowing to ca n y out of analytical research of process continuous rolling on mills with the various technological circuits of manufacture is created. With the help of the developed information-analytical system continuous rolling, the urgent tasks of manufacture of hire on rolling mills, in particular, decrease of consumption of power resources can be successfully decided during continuous rolling at the expense of optimization existing or development of the new technological circuits of manufacture of hire

Study of Current State of Templates Cut Out of VVER-440 Reactor Pressure Vessel

This article presents the results of structural study of base (BM) and weld metal (WM) templets in current state cut from different areas of VVER-440 reactor pressure vessel (RPV) by TEM, SEM, APT as well as fractographic analysis results. The phase composition of irradiated BM and WM is shown to be represented by hardening phases - dislocation loops, initial carbides, thermally-stimulated vanadium carbonitrides, Cu-rich radiation-induced precipitates, playing the main role in hardening of RPV metal under irradiation. Phase composition of nonirradiated BM and WM is represented by hardening phases - carbides and thermally-stimulated vanadium carbonitrides. Fractographic analysis revealed the level of grain boundary segregations and showed the share of brittle intergranular fracture in the BM specimens to reach 65%, whereas in the WM specimens demonstrate no grain boundary embrittlement, which is due to their microstructure peculiarities

PECULIARITIES OF THE FEED TEMPERATURE CHANGING ALONG THE MILL 320 UNE OF RUP "BMZ" AT ROLLING OF REINFORCING PROFILES BY MEANS OF ROLLING-AND-SEPARATION

The peculiarities of the temperature changing of the roll along the length of mill at using of new technological schema of production of reinforce rolled metal of small cuts in conditions of RUP are considered