n the field of non-destructive testing, the test pieces serve as so-called comparative gauges, which are designed to adjust the basic sensitivity of an ultrasonic instrument for testing the steam generator. The test pieces should reflect as closely as possible the tested com...

One method for evaluating the mechanical properties of materials is the use of methods that focus on the use of miniaturized test specimens. This paper describes and compares the results of high-cycle fatigue of X1CrNiMoAlTi steel with the use of on standard test sample...

The knowledge of material parameters of construction steels is the key for the proper design and analysis of the components used in power engineering and in other disciplines of technical practice. To identify these parameters, series of tests and measurements are commonly &...

Reactor pressure vessel internals of nuclear power plants are exposed to severe operating conditions (high pressure and temperatures, neutron flux, corrosion environment), which cause gradual degradation of their mechanical properties. Thermal annealing can be one of the possible solution...

This paper documents the microstructure changes of steel SUPER 304H caused by high temperature overheating (1140 °C, 15 hours). The experimental material was firstly isothermally laboratory exposed about 30,000 hours at temperature 650 °C and then subject to high temperature ove...

The operating time of most energy and chemical plants in the Czech Republic is an important reason for the development of diagnostic and operational monitoring systems that would greatly contribute to reducing the risk of a high-temperature high-pressure pipeline accident. And &#...

Spent nuclear fuel from a VVER-440-type power plant is stored in Slovakia in the Interim Spent Fuel Storage (ISFS) pools in special KZ-48 compact racks. They are made of chromium-nickel stainless steel with guaranteed boron content min. 1.10 wt. %, which serves as a ther...

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 v...

This study was focused on lowering of hydrogen embrittlement which is caused by pickling process. Different types of adsorption inhibitors were used as additives to pickling bath in order to prevent metal dissolution and related hydrogen evolution. The effect of inhibitors was&#x...

Paper describes the currently used definition and classification of corrosion risk assessment for turbine materials, which is newly supplemented by two criteria. In addition to recommending methodologies for the collection and analysis of deposition, the motivation is to create evaluation&...

Evaluation of the operational dependability is such an activity that needs to be based on relevant data sources. Those data significantly corresponds with the solution of operational dependability so they have its own specificities, which are described in the following contribution.

The presence of partial discharges indicates advancing degradation of stator winding insulation system. The level of partial discharges depends on the insulation quality, the quality of location in the grooves and quality of semi-conductive layer of the insulation. As the degrad...

The transonic or supersonic flow of working wet steam is detected in the last stages of steam turbines low pressure parts. In text below there are presented losses generated in a turbine airfoil channel by transonic or supersonic flow. Next is modernization of turbine&#...

Online evaluation and prediction of turbine generator failures is a key factor for its successful long-term operation. Generator torque fluctuations, caused by, for example, non-stationary conditions in the power grid, affect the shaft torsional vibration as well as the vibration of&#...

Tilting pad bearings can be found in rotating machinery with high circumferential speeds of journals. Vibrations of individual pads are usually neglected in rotordynamics simulations and hydrodynamic forces acting in oil films are often linearized. A computational model which respect...

Repeated 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 ...

The demands on results of NDT inspections are increasing continually. The determination of discontinuity dimensions is expected as an output at present time, not only the dimensions of indication or other imaginary values. So some people rename the defectoscopy to &#...

The Potential Method is a suitable tool for online monitoring of the status of the pipelines. Measurements can be performed in full operation without the need for further intervention. The result of the measurement is information about the change in wall thickness,&#x...

This paper discusses current or upcoming projects of the Research Centre Rez for the field of perspective NDT methods such as the use of nonlinear ultrasonic spectroscopy methods and magnetic memory of the equipment as scanning methods for detecting cracks in the ...