A5047886996- High Temperature Alloys and Creep
- Fatigue and fracture mechanics
- Additive Manufacturing Materials and Processes
- Microstructure and Mechanical Properties of Steels
- Welding Techniques and Residual Stresses
- Fire effects on concrete materials
- Aluminum Alloy Microstructure Properties
- Metal Alloys Wear and Properties
- Additive Manufacturing and 3D Printing Technologies
- Metallurgy and Material Forming
- Hydrogen embrittlement and corrosion behaviors in metals
- High Entropy Alloys Studies
- Advanced Welding Techniques Analysis
- Surface Treatment and Coatings
- Nuclear Materials and Properties
- High-Velocity Impact and Material Behavior
- High-Temperature Coating Behaviors
- Aluminum Alloys Composites Properties
- Mechanical and Thermal Properties Analysis
- Metallurgy and Material Science
- Material Properties and Failure Mechanisms
- Industrial Vision Systems and Defect Detection
- Microstructure and mechanical properties
Czech Technical University in Prague
2015-2024
Ujp Praha (Czechia)
2016-2022
Czech Academy of Sciences, Institute of Physics
1991
In this article, strain-controlled Low-Cycle Fatigue (LCF) and fatigue-creep tests were performed on Inconel 718 nickel-based superalloy at temperatures of 650 °C 730 °C. LCF elevated with a mechanical strain rate 1×10−3/s, while involved either tensile or compressive dwell. Both the revealed cyclic softening, mean stress evolving oppositely to applied dwell in tests. Investigations into damage mechanisms identified intergranular cracking as predominant failure mode. Fatigue-creep loading...
Abstract Additive manufacturing (AM) is a progressive technology which holds promise for of heat resistant super alloys. One the most productive methods wire arc additive (WAAM). In this article, an alternative WAAM strategy investigated. Experimental clads and material tests were performed to evaluate properties obtained through cold metal transfer (CMT) discontinuous Inconel 625 alloy. Using modern terminology Fronius Gmbh method called CMT cycle step. The difference that it automatically...
Sheets of coarse-grained S304H austenitic steel were processed by high-pressure sliding (HPS) at room temperature and a ultrafine-grained microstructure with mean grain size about 0.14 µm was prepared. The changes creep behavior HPS-processed investigated 500-700 °C under the application different loads. It found that processing led to significant improvement in strength 500 °C. However, further increase 600 700 deterioration steel. results suggest is associated thermal stability...
Article presents results on the analysis of secondary phases formed in medium-term static isothermal ageing welding joints a SUPER 304H (675 • C/2 × 10 4 h).The investigations precipitates were focused occurrence σ-phase because its formation leads to significant deterioration mechanical properties.The microstructure was investigated microscopic level by scanning/transmission electron microscopy.The distribution and quantification brittle studied macroscopic color etching method using light...
Despite the current tendencies towards decarbonization of energy sector, it is still necessary to maintain lifetime existing coal-fired power plants. Austenitic stainless steels belong among materials used in energetics, this case, SUPER 304H (X10CrNiCuNb18-9-3). This steel for experiment that simulates real operating conditions, specifically high temperature (700°C) and constant inner pressure (25 MPa), which induced by inserting a distilled water medium before sealing. work deals with...
The paper presents the results of analysis secondary phases formed during thermal exposure in creep resistant austenitic steels SUPER 304H and HR3C types. These were worldwide used for construction superheaters (the heat exchangers) supercritical ultra-supercritical (USC) coal-fired power plants. In order to accelerate precipitation processes, isothermally aged at 675 °C 20 000 h. investigations precipitates primarily focused on occurrence brittle phases. Changes mechanical properties caused...
This article deals with the results of mechanical testing and structural analysis sections narrow gap orbital welded P91 steel on tube OD 355.6 x 40 mm. The evaluation properties was based tensile test at room temperature mini-tensile specimens measurement modulus elasticity. Weld cut longitudinally into 9 slices by using waterjet. From these 108 flat (dimensions gauge is 2 mm) were prepared. In experimental part microstructure documentation fracture surface each specimen carried out. aim...
Creep resistant 9% Cr steels are frequently used in civil engineering projects of supercritical coal‐fired power plants operating at temperatures superheated steam around 610 °C. This work focus on analysis microstructure degradation and mechanical properties orbital narrow‐gap welding P91 P92 steels. Nowadays technology using tungsten inert gas is not limited to high‐pressure pipelines. method highly productive efficient leads an increase productivity, quality, repeatability process. It...
This paper describes the influence of technological treatments (i.e., bending or welding) on structural stability SUPER304H austenitic steel used in reheaters and superheaters fossil fuel power plants. Although worldwide trend is transitioning to green sources, lifetime existing plants has be prolonged until transition complete. Experimental material was tested as-received state (straight tubes), bends, homogeneous weld joints. Part specimens solution-annealed after operation. Afterwards,...
In this article, strain-controlled Low-Cycle Fatigue (LCF) and fatigue-creep tests were performed on Inconel 718 nickel-based superalloy at temperatures of 650◦C 730◦C. LCF elevated with a mechanical strain rate 1 × 10−3/s, while involved either tensile or compressive dwell. Both the revealed cyclic softening, mean stress evolving oppositely to applied dwell in tests. Investigations into damage mechanisms identified intergranular cracking as predominant failure mode. Fatigue-creep loading...
This paper is focused on evaluation of the plastic deformation effect, after cold bending process for new austenitic material Super 304H designed supercritical conditions. The aim project was to qualify and then verify properties these bends in conditions approaching application. presents results effect changes structure mechanical at operating temperatures corrosive environments coal combustion products comparison before degradation. tests were carried out two dimensions tubes which are...
This paper deal with redistribution of chemical elements around cladding surface composite tube. Motivation is that change composition cause in microstructure and mainly changes mechanical properties. Local properties can inaccuracy or wrong results obtained from FEM modeling bending process In short present caused by heat input during production Redistribution weld attachment connector which used membrane waterwall discussed. Microstructure evaluation base material layer compared...