The process of regenerative heat treatment of the valve chamber of the steam turbine

• Autorzy: Wieczorska Agata

Identyfikatory

DOI

10.2478/kones-2019-0079

• Języki publikacji: EN

Abstrakty

EN

Steel castings are often used in the construction of valve chambers of steam turbines. Stringent requirements are set due to the continuous operation of the material at elevated temperatures, in the order of 300ºC to 600ºC. The material of the valve chamber must be resistant to fatigue-creep changes as well as corrosion. This material must be also resistant to dynamic damage which occures when the turbine is starting and stopping. Dynamic damage is induced by a short-lasting but intense accumulation of localized stresses. The castings of the valve chambers of the steam turbine are usually made from the “three-component” type CrMoV-cast steel. Mentioned castings of the valve chamber are continuously subjected to high temperatures, either constant and periodically variable stresses. Due to this, the degradation process of material of the castings is taking place. It is caused by physicochemical processes such as: creep, relaxation, thermal fatigue, corrosion, erosion and changes in material properties, e.g. displacement of the critical point of brittleness. Finally, first cracks and deformations can be observed in the material during the operation. The art presents the process of revitalization technology of the steam turbine valve chamber which was subjected to long-term operation at high temperatures. The revitalization process is aimed at improving the plastic properties of the material and, as the result, extending its service life. The research presented in the article show that impact strength of the chamber material after revitalization is very high. Also the strength properties of the valve chamber, after revitalization, are high and in line with the requirements. The study show that the revitalization of the valve chamber was carried out correctly and restored the material to plastic deformation.

Słowa kluczowe

EN

regenerative heat treatment; valve chamber; steam turbine

• Wydawca: Łukasiewicz Research Network - Institute of Aviation ; European Science Society of Powertrain and Transport KONES Poland ; Wydawnictwo Instytutu Technicznego Wojsk Lotniczych
• Czasopismo: Journal of KONES
• Rocznik: 2019
• Tom: Vol. 26, No. 3
• Strony: 243--248
• Opis fizyczny: Bibliogr. 6 poz., rys.

Twórcy

autor

Wieczorska Agata

• Gdynia Maritime University, Faculty of Marine Engineering Morska Street 81-87, 81-225 Gdynia, Poland tel.: [phone], fax: [phone]

Bibliografia

• [1] Dobosiewicz, J., Influence of exploitation on changes of mechanical properties of metal of steam turbine hulls, Energetyka, 1, p. 27, 1992.
• [2] Cicholska, M., Czechowski, M., Ship material science, publishing of the Maritime University of Gdynia, Gdynia 2013. 247
• [3] Expertise of repairs, EC Gdynia TG1.
• [4] Rajca, S., Grzesiczek, E., Condition of the material of the steam turbine hull after repair by welding, Energetyka, 12, s. 777, 2001.
• [5] Rehmus-Forc, A., Structural changes occurring after the revitalization of steam turbine hulls, Materials Engineering, No. 3, pp. 265-267, 2006.
• [6] Trzeszczyński, J., Grzesiczek, E., Replace or revitalize?, Energetyka, 7, 1998.

Uwagi

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2019).