Estimation of the residual life of L17HMF cast steel elements after long-term service

• Autorzy: Zieliński A. , Dobrzański J. , Golański G.
• Języki publikacji: EN

Abstrakty

EN

Purpose: of this paper is to present the changes of the mechanical properties and structure in material components of the power station boiler after long-term creep service made of G17CrMoV5-10 low-alloyed cast steel. Design/methodology/approach: The material of the research studies has been obtained from Polish power stations. Examined element has exceeded their assessed life of 105.000 hours. Mechanical properties and structure examinations were carried out on material after long-term service in creep conditions. The microstructure has been observed using a light and a scanning electron microscope. The investigation of the development of the precipitation processes was done by X-ray diffraction phase analysis. Findings: The microstructures and phase compositions of the residues, obtained from the elements, depend on life exhaustion extent. Practical implications: The presented method can be used for evaluation and qualification of structural changes in power station boiler and turbine components operating in creep conditions. Originality/value: The paper presents results of changes in the mechanical properties, structure and in the precipitation processes which are applied to evaluation for the condition of the elements in further industrial service.

Słowa kluczowe

EN

mechanical properties; structure phase analysis; degradation after creep service; residual life

PL

właściwości mechaniczne; analiza fazy strukturalnej; degradacja na skutek pełzania; wytrzymałość szczątkowa

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2009
• Tom: Vol. 34, nr 2
• Strony: 137--144
• Opis fizyczny: Bibliogr. 15 poz., rys., tabl.

Twórcy

autor

Zieliński A.

autor

Dobrzański J.

autor

Golański G.

• Institute for Ferrous Metallurgy, ul. K. Miarki 12, 44-100 Gliwice, Poland,

Bibliografia

• [1] J. Dobrzański, Analysis of structure and properties changes of the 1Cr - 0.5Mo type steel subjected to long-term creep as the basis for forecasting the life of the power industry equipment components, PhD Thesis, Katowice, 1995 (unpublished) (in Polish).
• [2] A. Hernas, J. Dobrzański, Life-time and Damage of Boilers and Steam Turbines Elements, Publishing House of the Silesian University of Technology, Gliwice, 2003 (in Polish).
• [3] D. Renowicz, A. Hernas, M. Cieśla, K. Mutwil, Degradation of the cast steel parts working in power plant pipelines, Journal of Achievements in Materials and Manufacturing Engineering 18 (2006) 219-222.
• [4] J. Okrajni, K. Mutwil, M. Cieśla, Chemical pipelines material fatigue, Journal of Materials Processing Technology 164-165 (2005) 897-904.
• [5] J. Dobrzański, A. Zieliński, Accelerated high-temperature creep tests for assessment of service life of power engineering steel, , Proceedings of the 8th Seminar “Materials Investigation for Power Industry”, Zakopane, 2002, 97-100 (in Polish).
• [6] G. Golański, J. Kupczyk., S. Stachura, B. Gajda, Regenerative heat treatment of L21HMF cast steel after long term operation, proceedings of the Conference “Materials for Advanced Power Engineering 2006”, Liege, 2006, 1087-1095.
• [7] J. Dobrzański, M. Sroka, A. Zieliński, Methodology of classification of internal damage the steels during creep service, Journal of Achievements in Materials and Manufacturing Engineering 18 (2006) 263-266.
• [8] A. Zieliński, A. Hernas, Forecasting residual life of cast steel elements of pipelines working under creep and fatigue conditions, IMZ Reports 4 (2008) 1-17 (in Polish).
• [9] G. Golański, S. Stachura, B. Gajda-Kucharska, J. Kupczyk, Optimisation of regenerative heat treatment parameters of G21CrMoV4-6 cast steel, Archives of Materials Science and Engineering 28/6 (2007) 341-344.
• [10] A. Zieliński, J. Dobrzański, H. Krztoń, Structural changes in low alloy cast steel Cr-Mo-V after long time creep service, Journal of Achievements in Materials and Manufacturing Engineering 25/1 (2007) 33-36.
• [11] A. Zieliński, J. Dobrzański, D. Renowicz, A. Hernas, The estimation of residual life of low-alloy cast steel Cr-Mo-V type after long-term creep service, Proceedings of the 5th International Conference “Advances in Materials Technology for Fossil Power Plants” EPRI, Marco Island, USA, 2007, 34-35.
• [12] J. Okrajni, A. Marek, G. Junak, Description of the deformation process under thermo-mechanical fatigue, Journal of Achievements in Materials and Manufacturing Engineering 21/2 (2007) 15-24.
• [13] R. Pasierb, Welding of head resistance steel Cr-Mo-V, WNT, Warsaw, 1982 (in Polish).
• [14] J. Dobrzański, A. Hernas, Correlation between phase composition and life-time of 1Cr-0,5Mo steels during long term service, Journal of Materials Processing Technology 53 (1995) 101-108.
• [15] D. Renowicz. M. Cieśla, Crack initiation in Steel Parts Working under Thermo-Mechanical Fatigue Conditions, International Journal of Computational Materials Science and Surface Engineering (2009) (in print).