Review of the damage mechanism in wind turbine gearbox bearings under rolling contact fatigue

Abstract

Wind turbine gearbox bearings fail with the service life is much shorter than the designed life. Gearbox bearings are subjected to rolling contact fatigue (RCF) and they are observed to fail due to axial cracking, surface flaking, and the formation of white etching areas (WEAs). The current study reviewed these three typical failure modes. The underlying dominant mechanisms were discussed with emphasis on the formation mechanism of WEAs. Although numerous studies have been carried out, the formation of WEAs remains unclear. The prevailing mechanism of the rubbing of crack faces that generates WEAs was questioned by the authors. WEAs were compared with adiabatic shear bands (ASBs) generated in the high strain rate deformation in terms of microstructural compositions, grain refinement, and formation mechanism. Results indicate that a number of similarities exist between them. However, substantial evidence is required to verify whether or not WEAs and ASBs are the same matters.

Key words： rolling contact fatigue (RCF); white etching area (WEA); white etching crack (WEC); adiabatic shear band (ASB)

Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (Grant No. 51275225).

References

1 Whittle M, Trevelyan J, Tavner P J. Bearing currents in wind turbine generators. Journal of Renewable and Sustainable Energy, 2013, 5(5): 053128

2 Evans M H. White structure flaking (WSF) in wind turbine gearbox bearings: Effects of ‘butterflies’ and white etching cracks (WECs). Materials Science and Technology, 2012, 28(1): 3–22

3 Morthorst P E, Awerbuch S. The Economics of Wind Energy: A report by the European Wind Energy Association. 2009.

4 Evans M H, Walker J C, Ma C, A FIB/TEM study of butterfly crack formation and white etching area (WEA) microstructural changes under rolling contact fatigue in 100Cr6 bearing steel. Materials Science and Engineering: A, 2013, 570: 127–134

5 Grabulov A, Petrov R, Zandbergen H W. EBSD investigation of the crack initiation and TEM/FIB analyses of the microstructural changes around the cracks formed under rolling contact fatigue (RCF). International Journal of Fatigue, 2010, 32(3): 576–583

6 Evans M H, Richardson A D, Wang L, Serial sectioning investigation of butterfly and white etching crack (WEC) formation in wind turbine gearbox bearings. Wear, 2013, 302(1–2): 1573–1582

7 Grabulov A, Ziese U, Zandbergen H W. TEM/SEM investigation of microstructural changes within the white etching area under rolling contact fatigue and 3-D crack reconstruction by focused ion beam. Scripta Materialia, 2007, 57(7): 635–638

8 Hashimoto K, Hiraoka K, Kida K, Effect of sulphide inclusions on rolling contact fatigue life of bearing steels. Materials Science and Technology, 2012, 28(1): 39–43

9 Errichello R, Budny R, Eckert R. Investigations of bearing failures associated with white etching areas (WEAs) in wind turbine gearboxes. Tribology Transactions, 2013, 56(6): 1069–1076

10 Evans M H. An updated review: White etching cracks (WECs) and axial cracks in wind turbine gearbox bearings. Materials Science and Technology, 2016, 32(11): 1133–1169

11 Janakiraman S, West O, Klit P, Observations of the effect of varying hoop stress on fatigue failure and the formation of white etching areas in hydrogen infused 100Cr6 steel rings. International Journal of Fatigue, 2015, 77: 128–140

12 Luyckx J. White etching crack failure mode in roller bearings: From observation via analysis to understanding and an industrial solution. Rolling Element Bearings, 2012, 1542: 1–25

13 Luyckx J. Hammering wear impact fatigue hypothesis WEC/irWEA failure mode on roller bearings. 2011.

14 Sakai T, Lian B, Takeda M, Statistical duplex S-N, characteristics of high carbon chromium bearing steel in rotating bending in very high cycle regime. International Journal of Fatigue, 2010, 32(3): 497–504

15 Ruellan A, Ville F, Kleber X. Understanding white etching cracks in rolling element bearings: The effect of hydrogen charging on the formation mechanisms. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2014, 228(11): 1252–1265

16 Li Y, Kang G, Wang C, Vertical short-crack behavior and its application in rolling contact fatigue. International Journal of Fatigue, 2006, 28(7): 804–811

17 Donzella G, Petrogalli C. A failure assessment diagram for components subjected to rolling contact loading. International Journal of Fatigue, 2010, 32(2): 256–268

18 Kailas S V. A study of the strain rate microstructural response and wear of metals. Journal of Materials Engineering and Performance, 2003, 12(6): 629–637

19 Seo J W, Jun H K, Kwon S J, Rolling contact fatigue and wear of two different rail steels under rolling-sliding contact. International Journal of Fatigue, 2016, 83: 184–194

20 Holweger W, Wolf M, Merk D, White etching crack root cause investigations. Tribology Transactions, 2015, 58(1): 59–69

21 Gould B, Greco A. The influence of sliding and contact severity on the generation of white etching cracks. Tribology Letters, 2015, 60(2): 29

22 Nélias D, Dumont M L, Champiot F, Role of inclusions, surface roughness and operating conditions on rolling contact fatigue. Journal of Tribology, 1999, 121(2): 240–250

23 Solano-Alvarez W, Pickering E J, Peet M J, Soft novel form of white-etching matter and ductile failure of carbide-free bainitic steels under rolling contact stresses. Acta Materialia, 2016, 121: 215–226

24 Kang J H, Hosseinkhani B, Rivera-díaz-del-castillo P E J. Rolling contact fatigue in bearings: Multiscale overview. Materials Science and Technology, 2012, 28(1): 44–49

25 Harada H, Mikami T, Shibata M, Microstructural changes and crack initiation with white etching area formation under rolling/sliding contact in bearing steel. ISIJ International, 2005, 45(12): 1897–1902

26 Baumann G, Knothe K, Fecht H J. Surface modification, corrugation and nanostructure formation of high speed railway tracks. Nanostructured Materials, 1997, 9(1–8): 751–754

27 Qin X, Sun D, Xie L, Hardening mechanism of Cr5 backup roll material induced by rolling contact fatigue. Materials Science and Engineering: A, 2014, 600: 195–199

28 Evans M H, Richardson A D, Wang L, Confirming subsurface initiation at non-metallic inclusions as one mechanism for white etching crack (WEC) formation. Tribology International, 2014, 75: 87–97

29 Imai Y, Endo T, Dong D, Study on rolling contact fatigue in hydrogen environment at a contact pressure below basic static load capacity. Tribology Transactions, 2010, 53(5): 764–770

30 Uyama H, Yamada H, Hidaka H, The effects of hydrogen on microstructural change and surface originated flaking in rolling contact fatigue. Tribology Online, 2011, 6(2): 123–132

31 Bruce T, Rounding E, Long H, Characterisation of white etching crack damage in wind turbine gear-box bearings. Wear, 2015, 338–339: 164–177

32 Kino N, Otani K. The influence of hydrogen on rolling contact fatigue life and its improvement. JSAE Review, 2003, 24(3): 289–294

33 Vegter R H, Slycke J T, Beswick J, The role of hydrogen on rolling contact fatigue response of rolling element bearings. Journal of ASTM International, 2010, 7(2): 102543

34 Hiraoka K, Fujimatsu T, Tsunekage N, Generation process observation of microstructural change in rolling contact fatigue by hydrogen-charged specimens. Japanese Journal of Tribology, 2007, 52(6): 673–683

35 Ray D, Vincent L, Coquillet B, Hydrogen embrittlement of a stainless ball bearing steel. Wear, 1980, 65(1): 103–111

36 Hamada H, Matsubara Y. The influence of hydrogen on tension-compression and rolling contact fatigue properties in bearing steel. NTN Technical Review, 2006, 74: 54–61

37 Evans M H, Richardson A D, Wang L, Effect of hydrogen on butterfly and white etching crack (WEC) formation under rolling contact fatigue (RCF). Wear, 2013, 306(1–2): 226–241

38 Kang J H, Vegter R H, Rivera-Díaz-del-Castillo P E J. Rolling contact fatigue in martensitic 100Cr6: Subsurface hardening and crack formation. Materials Science and Engineering: A, 2014, 607: 328–333

39 Kang J H, Hosseinkhani B, Williams C A, Solute redistribution in the nanocrystalline structure formed in bearing steels. Scripta Materialia, 2013, 69(8): 630–633

40 Li S, Su Y, Shu X, Microstructural evolution in bearing steel under rolling contact fatigue. Wear, 2017, 380–381: 146–153

41 Lai J, Stadler K. Investigation on the mechanisms of white etching crack (WEC) formation in rolling contact fatigue and identification of a root cause for bearing premature failure. Wear, 2016, 364–365: 244–256

42 Hiraoka K, Nagao M, Isomoto T. Study on flaking process in bearings by white etching area generation. Journal of ASTM International, 2006, 3(5): 14059

43 Solano-Alvarez W, Duff J, Smith M C, Elucidating white-etching matter through high-strain rate tensile testing. Materials Science and Technology, 2017, 33(3): 307–310

44 Warhadpande A, Sadeghi F, Evans R D. Microstructural alterations in bearing steels under rolling contact fatigue Part 1—Historical overview. Tribology Transactions, 2013, 56(3): 349–358

45 Gould B, Greco A. Investigating the process of white etching crack initiation in bearing steel. Tribology Letters, 2016, 62(2): 26

46 Wei Q, Kecskes L, Jiao T, Adiabatic shear banding in ultrafine-grained Fe processed by severe plastic deformation. Acta Materialia, 2004, 52(7): 1859–1869

47 Li N, Wang Y D, Lin Peng R, Localized amorphism after high-strain-rate deformation in TWIP steel. Acta Materialia, 2011, 59(16): 6369–6377

48 Li S, Zhao P, He Y, Microstructural evolution associated with shear location of AISI 52100 under high strain rate loading. Materials Science and Engineering: A, 2016, 662: 46–53

49 Wang B F, Yang Y. Microstructure evolution in adiabatic shear band in fine-grain-sized Ti-3Al-5Mo-4.5V alloy. Materials Science and Engineering: A, 2008, 473(1–2): 306–311

50 Peirs J, Tirry W, Amin-Ahmadi B, Microstructure of adiabatic shear bands in Ti6Al4V. Materials Characterization, 2013, 75: 79–92

51 Voskamp A P. Material response to rolling contact loading. Journal of Tribology, 1985, 107(3): 359–364