Corrosion attack evaluation of homogeneous weld joint of austenitic tube and flange

V současné době je často řešeným problémem korozní napadení heterogenních svarových spojů, nicméně korozní napadení se objevuje i na homogenních svarových spojích. V předkládaném příspěvku je popsáno hodnocení korozního napadení austenitické příruby svařené s trubkou. U svarového kovu byla patrná koroze materiálu do třetiny tloušťky trubky a v základním materiálu austenitické trubky byla pozorována podpovrchová koroze.The problem of heterogeneous weld joints corrosion attack is often solved, but corrosion attack also occurs on homogeneous weld joints. The paper describes the evaluation of corrosion attack of austenitic flange welded with a tube. In the weld metal, material corrosion was visible to one third of the thickness of the tube and subsurface corrosion was observed in the base material of the austenitic tube

The Potential For Development of an Integrated Network of Greenway Trails on Medieval Hedgerows Landscapes in the Czech Republic

Today in the Pilzen region of the Czech Republic, remnants of medieval fields known as “pluzinas” represent an extremely valuable historical landscape pattern. The character of a pluzina landscape is in many aspects comparable to the hedged field (bocage) landscapes that are well known as a symbol of some parts of Europe, e.g. Belgium (Flanders), England, Scotland, Wales, France (Brittany and Normandy) or the Irish highlands. The character of preserved pluzinas in the Czech Republic differs from that of typical bocage landscapes in some respects, especially in spatial composition. In pluzinas, long parallel plots connected to the individual farmsteads of the village prevail, with a minimum of shorter, transversal hedgerows (see Figure. 1)

Analysis of the causes of impeller damage in NPP Temelín

Při revizi čerpadla SULZER 200-450 byla na oběžném kole 2TQ32D01 na základě vizuální a kapilární kontroly zjištěna na jedné z pěti lopatek trhlina. Oběžné kolo bylo za účelem stanovení příčin poškození převezeno k destruktivnímu hodnocení do ÚJV Řež, a. s. Destruktivním hodnocením bylo zjištěno únavové poškození lopatky. Hodnocení bylo komplexně doplněno ověřením chemického složení materiálu, odporovou tenzometrií a stanovením základních mechanických vlastností.During the revision of the pump SULZER 200-450 of the impeller 2TQ32D01, a crack was detected on one of the five blades based on visual and capillary inspection. In order to determine the causes of damage, the impeller was transferred to ÚJV Řež. Destructive evaluation revealed fatigue damage to the blade. The evaluation was comprehensively supplemented by verification of the chemical composition of the material, resistance tensometry and determination of basic mechanical properties

Thermally modified (TM) beech wood: compression properties, fracture toughness and cohesive law in mode II obtained from the three-point end-notched flexure (3ENF) test

[EN] The fracture properties of thermally modified beech (Fagus sylvatica) wood (TMW) at 180 degrees and 200 degrees C were evaluated in mode II using the three-point end-notched flexure (3ENF) scheme assisted by three-dimensional (3D) stereovision equipment for obtaining displacements and strains. The compliance-based beam method (CBBM) provided the strain energy release rates (G(II)) of TMW and cohesive laws for both native wood (W) and TMW. Based on the CBBM and equivalent crack length approach (ECLA), G(II) was obtained directly from the force-deflection data. The thermal modification (TM) process reduced the compressive strength by 4.4% and increased the compressive elastic modulus by 38.3%, whereas G(II) was reduced substantially by 40.8% and 67.9% at TM180 degrees C and TM200 degrees C, respectively. TM also increased wood brittleness that was visible on the displacement slip reduction. The resulting mean cohesive models can be used for numerical analyses. The fracture properties of TMW have to be taken into consideration for constructional wood application, when cyclic loading may lead to microcracking and material fatigue.The authors would like to thank COST Action FP1407 (Funder Id: https://dx.doi.org/10.13039/501100000921), the European Commission for funding the InnoRenew CoE project under the Horizon2020 Widespread-Teaming program (grant agreement #739574), the Republic of Slovenia for providing support from the European Regional Development Funds, and the financial support provided by the Internal Grant Agency (IGA) of the Faculty of Forestry and Wood Technology, Mendel University in Brno (LDF_PSV_2016015).Sebera, V.; Redón-Santafé, M.; Brabec, M.; Decky, D.; Cermak, P.; Tippner, J.; Milch, J. (2019). Thermally modified (TM) beech wood: compression properties, fracture toughness and cohesive law in mode II obtained from the three-point end-notched flexure (3ENF) test. Holzforschung. 73(7):663-672. https://doi.org/10.1515/hf-2018-018866367273

Damage assesment of the cooling inserts of dieselgenerator 6ZL40/48 at NPP DUKOVANY

Opakovaná poškození chladících kroužků koruny pístu DG (v 2013 a 2017) vyvolala program na hodnocení mikrostruktury, mechanických vlastností a ověření chemického složení materiálu poškozených i nepoškozených chladících kroužků za účelem stanovení příčiny poškození a doporučení pro provozRepeated damages of cooling inserts at DG piston crown in 2013 and 2017 lead to experimental program in UJV. Microstructure evaluation, mechanical properties measurement and Chemical analysis were carried out on damaged and undamaged cooling inserts as well for to assess the root damage and to give recommendation for operation

Defect analysis of the npp turbogenerator blade

Při pravidelné kontrole provedené magnetickou práškovou metodou byly na povrchu v oblasti listu náběžné hrany lopatky NT rotoru turbogenerátoru nalezeny čtyři lineární indikace. Na základě těchto výsledků bylo rozhodnuto o převezení lopatky do akreditovaných laboratoří ÚJV Řež, a. s., kde byly indikace podrobeny detailnímu destruktivnímu hodnocení. Cílem hodnocení bylo objasnění příčin vzniku indikací na poškozené lopatce a doporučení pro další provoz.During the periodic inspection, four linear indications were found on the surface of the turbogenerator rotor blade in the region of the leading edge using the magnetic powder NDT method. Based on these results, a transfer of the blade to the accredited laboratories of ÚJV Řež, a. s. was decided. The indications were subjected to a detailed destructive evaluation. The evaluation aimed to clarify the cause of the defect detected on the blade and provide recommendations for further operation