Feasibility Analysis for Repair of Large Diameter Hydro Turbine Shaft Based on Weldability Test and Welding Cycle Simulation

Abstract:

Turbine and generator rotors and shafts undergo high stresses during regular working life and, from a safety and operational aspect, are the most significant components of a power generation system. Depending on the appropriate operating conditions, like temperature and/or corrosion the, shafts can be fabricated out of low/high alloy heat resistance material or of low alloyed, highly toughened material for different application. Despite known good practice and developed operation procedures, the failures of shafts sometimes occur. The right and well-defined failure analysis is the basis for feasibility analysis of repair method in the power generating industry. The analysis of direct and indirect costs of repair after the failure analysis as well as the analysis of the repair and post-repair conditions of the repaired element is the vital for decision on the key question. Is it possible to repair this element and what is the optimal repair strategy This paper compares and analyses two approaches, by weldability analysis and weld cycle simulation, in order to determine welding feasibility analysis of cracked hydro turbine shafts.

• Periodical: Advanced Materials Research (Volume 1153)
• Pages: 36-45
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1153.36
• Online since: May 2019
• Authors: Dejan Momčilović*, Zoran Odanović
• Keywords: Failure, Fatigue, Feasibility Study, Repair, Turbine Shaft, Weld Cycle Simulation, Weldability

References

[1] N. Bachschmid, P. Pennacchi, E. Tanzi, Cracked Rotors - A Survey on Static and Dynamic Behaviour Including Modelling and Diagnosis, Springer Heidelberg-Berlin, (2010).

DOI: 10.1007/978-3-642-01485-7

[2] W. Braitsch, H. Haas, Turbines for hydroelectric power, In: K. Heinloth (ed), Landolt-Börnstein, Group VIII: Advanced Materials and Technologies, Vol. 3: Energy Technologies, Subvol. C: Renewable Energies, Springer Verlag, Heidelberg-Berlin, 2006, pp.493-604.

DOI: 10.1007/10858992_8

[3] D. Momčilović et al.: Failure Analysis of Hydraulic Turbine Shaft, Engineering Failure Analysis, Published by Elsevier, Volume 20, (2012) 54-66.

DOI: 10.1016/j.engfailanal.2011.10.006

[4] GOST 977-88, Steel Catings. General Specification.

[5] W. R. Revie, H.H. Uhlig, Corrosion and corrosion control. John Wiley & Sons, Inc; (2008).

[6] R.P. Gangloff. Corrosion fatigue cracking, In: R. Baboian ed, Corrosion tests and standards: application and interpretation [2nd ed.].ASM International; 2005. p.302–21.

DOI: 10.1520/mnl11032m

[7] P. P. Milella, Fatigue and Corrosion in Metals, Springer-Verlag Italia, (2013).

[8] I. Atanasovska, R. Mitrović, and D. Momčilović, FEM model for calculation of Hydro turbine shaft, in: Proceedings – the Sixth International Symposium KOD 2010, Palić, Serbia, pp.183-188, (2010).

[9] D. Momčilović, A. Subić, I. Atanasovska, R. Mitrović, Combined Load Simulation vs Component Loads Simulation in Machine Design–a Case Study, FME Transactions, Faculty of Mechanical Engineering, University of Belgrade, (2014) 48-55.

DOI: 10.5937/fmet1401048m

[10] R. Mitrović, D. Momčilović, I. Atanasovska, Assessment of the Effect of Pitting Corrosion on Fatigue Crack Initiation in Hydro Turbine Shaft, Advanced Materials Research, In A. Subić,: Advances in Engineering Materials, Product and Systems Design (Special topic volume with invited peer reviewed papers only), Trans Tech Publications, Switzerland, (2013) pp.186-196.

DOI: 10.4028/www.scientific.net/amr.633.186

[11] D. Momčilović, R. Mitrović, I. Atanasovska, T. Vuherer, Methodology of determination the influence of corrosion pit on decrease of hydro trubine shaft fatigue life, Journal Machine Design, Published by University of Novi Sad, Faculty of Technical Sciences, Vol. 4 No.4, (2012) pp.231-236.

[12] G. Sabnavis, G. Kirk, M. Kasarda, D. Quinn, Cracked Shaft Detection and Diagnostics: A Literature Review, The Shock and Vibration Digest, (2004) 287-296.

DOI: 10.1177/0583102404045439

[13] L. K. Keppas, L.K., Combination of simulation and experiment in designing repair weld strategies: A feasibility study, Nuclear Engineering and Design 240, (2010) 2897–2906.

DOI: 10.1016/j.nucengdes.2010.05.034

[14] W. Janssen, Welding on Rotors for Power Plant Turbo Sets State of the Art, Siemens (2006).

[15] A. Aloraier, A. Almazrouee, J.W.H. Price, Weld repair practices without post weld heat treatment for ferritic alloys and their consequences on residual stresses: A review, International Journal of Pressure Vessels and Piping v. 87(4), (2010) 127-133.

DOI: 10.1016/j.ijpvp.2010.02.001

[16] A.K. Bhaduri, S.K. Albert, B. Raj, Robust welding technologies for ferrous alloys: Weld Cracking in Ferrous Alloys, Woodhead Publishing, (2009) 34-95.

DOI: 10.1533/9781845695453.1.34

[17] Y. Ito, K. Bessyo: Weldability formula of high strength steels, related to heat-affected zone cracking. Sumitomo Search, and IIW-Doc IX-631-69(1969),1-18.,1 (1969), 5, pp.59-70.

[18] N. Yurioka, et. al.: Study on carbon equivalents to assess cold cracking tendency and hardness in steel welding; Australian Weld. Res. Ass. Melbourne 19.-20.03.81, (1981) 1-18.

[19] N. Yurioka, N., M. Okumura, T. Kasuya and H. J. U. Cotton: Prediction of HAZ Hardness of Transformable Steels. Metal Construction (1987), 217R - 223R.

[20] I. Hrivnak, Theory of Weldability of Metals and Alloys, Elsevier Science Publishers, , ISBN 0-444-98707-X, Amsterdam, (1991).

[21] Odanovic et al, Selection of the optimal filler material for on-site welding of the turbine shaft at the hydropower plant, Welding and welded structures, No, 4, (2011) 149-166.

[22] T. Boellinghaus, J.C. Lippold, C.E. Cross, Cracking phenomena in welds IV, Springer International Publishing, Switzerland (2016).

DOI: 10.1007/978-3-319-28434-7

[23] J.L. Meseguer-Valdenebro, J.L. et al.: Calculation of Δt8/5 by Response Surface Metthodology for Electric Arc Welding , Thermal Science 18 (2014), Suppl. 1, p. S149 - S158.

[24] V.N. Lazic, V. N., Theoretical-Experimental Determining of Cooling Time (T(8/5)) in Hard Facing of Steels for Forging Dies, Thermal Science, 14,(1), (2010) p.235–246.

DOI: 10.2298/tsci1001235l

[25] A. Hobbacher, Recommendations for fatigue Design of SWelded Joints and Components, , IIW document IIW-1823-07, (2008).

DOI: 10.1007/978-3-319-23757-2

[26] H. Petershagen, IIW Recommendations on the Repair of Fatigue-Loaded Welded Structures. IIW document. XIII-1632-96, (1996).

[27] J. Krebs, M. Kassner, Influence of welding residual stresses on fatigue design of welded joints and components. IIW document XIII-2126-06/XV-1220-06, (2006).

DOI: 10.1007/bf03266586