Development of the precipitation processes in low-alloy Cr-Mo type steel for evolution of the material state after exceeding the assessed lifetime

• Autorzy: Dobrzański J. , Krztoń H. , Zieliński A.
• Języki publikacji: EN

Abstrakty

EN

Purpose: of this paper is to present the changes of the structure and of the carbides composition in material components made of 13CrMo44 after long term service in creep conditions. Design/methodology/approach: The material of the research studies has been obtained from Polish power stations. All examined elements have exceeded their assessed life of 100,000 hours. The microstructures of the elements have been observed using a scanning electron microscope. The mechanical properties and hardness values have been obtained. X-ray diffraction has been used for identification of carbides. The Rietveld method has been applied to calculate factions of the carbides. Findings: The correlation between changes in the carbides' composition and equivalent service time and exhaustion extent has been presented. Practical implications: The presented method can be used for evaluation and qualification of structural changes in power station boiler components operating in creep conditions. Originality/value: The application of the Rietveld method for quantification of the carbides for evaluation of the state of the material being in operating conditions.

Słowa kluczowe

EN

metallic alloys; phase analysis; Rietveld method; SIROQUANT(TM)

PL

stopy metaliczne; analiza fazowa; metoda Rietvelda; SIROQUANT(TM)

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2007
• Tom: Vol. 23, nr 2
• Strony: 19--22
• Opis fizyczny: Bibliogr. 15 poz., rys., tab.

Twórcy

autor

Dobrzański J.

autor

Krztoń H.

autor

Zieliński A.

• Institute for Ferrous Metallurgy, ul. K. Miarki 12/14, 44-100 Gliwice, Poland,

Bibliografia

• [1] A. Hernas, J. Dobrzański, Life-time and Damage of Boilers and Steam Turbines Elements, Silesian University of Technology Press, Gliwice, 2003 (in Polish).
• [2] J. Dobrzański, The classification method and the technical condition evaluation of the critical elements material of power boilers in creep service made from the 12Cr-lMo-V, Journal of Materials Processing Technology 164-165 (2005) 785-794.
• [3] J. Dobrzański, Material diagnostics in evaluation of the state and extended service time forecast in addition to the computational life of pipelines in creep service, Power Engineering 12 (2002) 937-946 (in Polish).
• [4] J. Dobrzański, Internal damage processes in low alloy chromium-molybdenum steels during high-temperature creep service, Journal of Materials Processing Technology 157-158 (2004) 197-303.
• [5] J. Dobrzański, A. Zieliński, State evaluation of critical elements material after long-term service in creep condition, Advances in Material Science, (2007) (in print).
• [6] J. Dobrzański, Analysis of structure and properties changes of the lCr - 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 (unpublished), 1995 (in Polish).
• [7] H. Krztoń et al., Development of applications of X-ray diffraction analysis, Report of Institute for Ferrous Metallurgy IFM No S0-0590 (2006) unpublished (in Polish).
• [8] J. Dobrzański, A. Hernas, Correlation between phase composition and life-time of lCr-0,5Mo steels during long term service at elevated temperature, Journal of Materials Processing Technology 53 (1995) 101-108.
• [9] D. Renowicz, M. Ciesla, Crack initiation in steel parts working in boilers and steam pipelines, Journal of Achievements in Materials and Manufacturing Engineering 21 (2007) 49-52.
• [10] J. Okrajni, K. Mutwil, M. Cieśla, Operating life of pipelines subjected to mechanical and thermal actions, Power Engineering 7 (2003) (in Polish).
• [11] S. Krol, M. Pietrzyk, Formation of corrosion products protecting surfaces of the boiler proper tubes from the combustion chamber, Journal of Achievements in Materials and Manufacturing Engineering 21 (2007) 45-48.
• [12] 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.
• [13] J. Okrajni, K. Mutwil, M. Cieśla, Chemical pipelines material fatigue, Journal of Materials Processing Technology 164-165 (2005) 897-904.
• [14] D. Renowicz, M. Plaza, M. Żelazkiewicz, A. Śliwka, Suspension Adjustment as a Method of Preventing Boiler Components Failures, Power Engineering 10 (1997) 540-543.
• [15] A. Hernas, Creep-resistance of steels and alloys, Silesian University of Technology, Gliwice, 2000 (in Polish).