Wyniki wyszukiwania - BazTech

1

Trwałość eksploatacyjna materiału wirników turbin parowych z niskostopowych stali Cr-Mo-V

Furmanek Joanna, Dobrzański Janusz

Energetyka

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2023

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nr 11

644--645

PL

W artykule przedstawiono wyniki badań materiałów wirników turbin parowych z niskostopowych stali typu Cr-Mo-V o różnym stopniu wyczerpania. Celem było określenie przydatności tych materiałów do dalszej eksploatacji po znacznym przekroczeniu obliczeniowego czasu pracy. Oceny stanu mikrostruktury dokonano na podstawie ujawnionych obrazów struktury w skaningowym mikroskopie elektronowym oraz stopnia rozwoju procesów wydzieleniowych po rentgenowskiej analizie składu fazowego osadów węglików. Oceny właściwości użytkowych dokonano na podstawie uzyskanych wyników właściwości mechanicznych w temperaturze pokojowej i podwyższonej oraz wyznaczonej trwałości resztkowej i resztkowej rozporządzalnej w skróconych próbach pełzania, a także na podstawie szybkości pełzania z krzywych pełzania dla parametrów temperaturowo-naprężeniowych odpowiadających eksploatacyjnym. Zaproponowano schemat zmian w strukturze badanych stali odniesionych do stopnia wyczerpania.

EN

The article presents the results of tests of materials for steam turbine rotors made of low-alloy Cr-Mo-V steels with various degrees of depletion. The aim was to determine the suitability of these materials for further use after exceeding the design operating time. The state of the microstructure was evaluated based on revealed images of the structure in the scanning electron microscope and the degree of development of the separation processes based on the X-ray analysis of the phase composition of the carbide deposits. The functional properties were evaluated based on the obtained results of mechanical properties at room and elevated temperatures, as well as the determined residual and residual disposable durability in abbreviated creep tests and creep rates from creep curves for temperature and stress parameters corresponding to operational ones. A scheme of changes in the structure of the tested steels related to the degree of exhaustion was proposed.

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Residual life of repair welded joints in pipelines made of 13HMF after use for the design operating time

Jasiński A., Zieliński A., Purzyńska H.

Prace Instytutu Metalurgii Żelaza

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2018

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T. 70, nr 3

2--10

EN

This paper presents the results of material tests of repair welded joints carried out for samples of materials taken from high pressure steam pipelines after over 200,000 operating hours in creep conditions, made of the 13HMF steel (14MoV6-3). The aim of the study was to assess the mechanical properties and changes in the structure of repair welded joints (new material + material after use), including the original material, heat affected zone and the weld, occurring as a result of the welding process and heat treatment after welding.

PL

W niniejszym opracowaniu zaprezentowano wyniki badań materiałowych przykładowych naprawczych złączy spawanych wykonanych na próbkach materiałów pobranych z rurociągów pary wysokoprężnej po przepracowaniu 200 tysięcy godzin pracy w warunkach pełzania, wykonanych ze stali 13HMF (14MoV6-3). Celem badań była ocena właściwości mechanicznych oraz zmian struktury naprawczych złączy spawanych (materiał nowy + materiał po eksploatacji) obejmujących materiał rodzimy, strefę wpływu ciepła i spoinę, zachodzących na skutek procesu spawania i przeprowadzonej obróbki cieplnej po spawaniu.

3

CrMoV steel welding in the narrow gap using of SAW technology

Holub L., Dunovský J., Suchánek J.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

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Vol. 62, nr 1

31--37

EN

Purpose: of this paper is the verification of multi-layer SAW welding the raw material “1.6946” by different welding consumables (TOPCORE 838 B, Thermatit MTS 616) in the „ultra” narrow gap using the prescribed temperature cycle and subsequent heat treatment. Design/methodology/approach: An evaluation of the mechanical properties of the test for both types welding consumables. The measured values of yield strength and the tensile strength exhibit comparable properties to the RAW material “Inspection Certificate” for welding consumable “TOPCORE 838 B”. Findings: Thermatit MTS 616” was found falling below the specified values of impact energy, ductility. The welding consumable TOPCORE 838 B shows less susceptibility to the brittleness. Based on the results will be verified by the existence of internal structures arising using the microstructure analysis & ARA diagram of the base material 1.6496. Research limitations/implications: Obtained results will be subsequently verified the existence of internal generated microstructures using the ARA chart of the base material (W Nr. 1.6496) for the future design of the new temperature cycles in all phases of the production. Originality/value: The welding consumable “TOPCORE 838 B” showed the low tendency to embrittlement in the heat-affected zone using the defined heat treatment. On the basic of the examination the welding consumable “TOPCORE 838 B” can be recommended to be used for the welding process, thermal cycle and heat treatment.

4

The impact of repair welded joint on the life of Cr-Mo-V steel steam pipeline after service under creep conditions

Zieliński A., Dziuba-Kałuża M., Dobrzański J., Sroka M.

Archives of Materials Science and Engineering

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2014

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Vol. 68, nr 1

36--44

EN

Purpose: The purpose of this paper was to examine the impact of repair welded joints on the life time of primary steam pipelines after more than 200 000 h service under creep conditions. Design/methodology/approach: The investigations of microstructure using scanning microscopy, investigations of mechanical properties at room and elevated temperature, determination of brittle fracture appearance transition temperature based on impact strength tests and abridged creep tests were carried out in order to determine the residual life of the material. Findings: The completed investigations allowed the time of further safe operation of the elements of primary steam pipeline with repair welded joint to be determined in relation to the parent material and welded joint after service. Practical implications: The assessment of residual life and disposable residual life, and thus the estimation or determination of possible time of further safe operation, is of the essence in case of operating the elements much beyond the design work time. Originality/value: The obtained results of investigations are the elements of material characteristics developed by the Institute for Ferrous Metallurgy for steels and welded joints made from them working under creep conditions.