Wyniki 1-1 spośród 1 dla zapytania: authorDesc:"Marek Stolorz"

Materials and technological aspects of coatings depositions for power plant industry DOI:10.15199/28.2019.4.2

  The general trends, associated with improving the performance and efficiency of power plant boilers are connected with the increasing the operating parameters of the boilers, which also contributes to the reduction of harmful emissions into the atmosphere. This development causes also an increase of heat load of the heat exchangers’ elements, in particular pipes of combustion chamber walls and superheaters. The high level of operating parameters of steam (temperature 750°C and pressure above 27 MPa) generates new demands related with the materials used for production of pressure elements in the boilers. The high level of surface temperature of the pipes causes a strong acceleration of corrosion processes and a reduction of resistance to abrasive wear (caused by impact particles of ash) of the utilized materials. These processes combined with the high pressures inside the pressure elements necessitate the use of new types of materials with improved mechanical properties and heat-resistance at higher temperature. These elements are usually made of high-alloyed steels and nickel-based materials [1]. One of the possibilities used for improvement of the operating properties of the top-surface of pressure elements being parts of heat exchangers is additional protection of worked surface by protective coatings with high resistance to erosive wear and corrosion. The basic technologies used for the coatings’ deposition are CVD (chemical vapour deposition) or PVD (physical vapour deposition) processes and especially different types of thermal spraying and welding processes. Each of these methods enables the production of coatings with specific properties resulting from theirs chemical and phases composition as well as from the internal structure. The most important factors that have a direct impact on the technical suitability of a particular type of coatings includes: thickness, hardness and porosity of the coatings [2]. The[...]

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