In this study, a blend-grind-peen repair technique was applied to a 12-Cr tempered martensitic steam turbine blade material containing a pre-existing fatigue crack. Manually grinding out the crack increased the elastic stress concentration factor Kt from 1.6 to 1.8. The repaired sample which was not re-peened showed a ∼50% improvement in cycles to failure compared with baseline samples. Sub-surface coalescence effects in shot peened surfaces are not always evident from surface crack measurements, which has implications for considering how much material to remove in such a repair. Despite the presence of a pre-existing crack, re-peening slowed the growth of the crack and extended the lifetime beyond that expected in the original shot peened surface.
HattinghDGJamesMNNewbyM, et al. Damage assessment and refurbishment of steam turbine blade/rotor attachment holes. Theor Appl Fract Mech2016; 83: 125–134. doi:https://doi.org/10.1016/j.tafmec.2015.11.001
2.
QinZLiBChenR, et al. Comparative study of the effects of conventional shot peening and ultrasonic shot peening on very high cycle fatigue properties of GH4169 superalloy. Int J Fatigue2023; 168: 107429. doi:https://doi.org/10.1016/j.ijfatigue.2022.107429
3.
ChenXGongZHuangH, et al. An Automated 3D Polishing Robotic System. Indu Autom J1999; 8: 6–11.
4.
HollingworthKOrtolanoR. The Application of Weld Repair Techniques to Reduce Costs and Outage Time of Steam turbines. Proce Inst Mech Eng, Part A: J Power Energy1990; 204: 87–97. doi:https://doi.org/10.1243/PIME_PROC_1990_204_171_02
5.
ClarkREAmosDR. Method for repairing a steam turbine or generator rotor. United States: Patent, 1987.
BhaduriAKGillTPSAlbertSK, et al. Repair welding of cracked steam turbine blades using austenitic and martensitic stainless-steel consumables. Nucl Eng Des2001; 206: 249–259. doi:https://doi.org/10.1016/S0029-5493(00)00439-8
Ünal-SaeweTGahnLKittelJ, et al. Process Development for Tip Repair of Complex Shaped Turbine Blades with IN718. Procedia Manuf2020; 47: 1050–1057. doi:https://doi.org/10.1016/j.promfg.2020.04.114
10.
ShrivastavaASAKRaoS, et al. Remanufacturing of nickel-based aero-engine components using metal additive manufacturing technology. Mater Today: Proce2021; 45: 4893–4897.
11.
EleicheAMMegahedMMAbd-AllahNM. The shot-peening effect on the HCF behavior of high-strength martensitic steels. J Mater Proces Technol2001; 113: 502–508. doi:https://doi.org/10.1016/S0924-0136(01)00601-X
12.
ZhangPLindemannJ. Influence of shot peening on high cycle fatigue properties of the high-strength wrought magnesium alloy AZ80. Scripta Mater2005; 52: 485–490. doi:https://doi.org/10.1016/j.scriptamat.2004.11.003
13.
DalaeiKKarlssonBSvenssonLE. Stability of shot peening induced residual stresses and their influence on fatigue lifetime. Mater Sci Eng: A2011; 528: 1008–1015. doi:https://doi.org/10.1016/j.msea.2010.09.050
14.
WuJLiuHWeiP, et al. Effect of shot peening coverage on residual stress and surface roughness of 18CrNiMo7-6 steel. Int J Mech Sci2020; 183: 105785. doi:https://doi.org/10.1016/j.ijmecsci.2020.105785
15.
ZhangXHuangSLiD, et al. An approach to improve the microstructure and mechanical properties: A hybrid manufacturing of laser directed energy deposition and shot peening. Add Manuf2022; 55: 102686. doi:https://doi.org/10.1016/j.addma.2022.102686
16.
SuwanpreechaCLinjeeSNewyawongP, et al. Effects of aging and shot peening on surface quality and fatigue properties of material extrusion additive manufactured 17-4PH stainless steel. Mater Des2024; 241: 112939. doi:https://doi.org/10.1016/j.matdes.2024.112939
17.
KlumppARufMDietrichS,et al.Long crack propagation and closure in DC(T) specimens of Ni-based superalloy Inconel 718 and stainless steel AISI 301 after shot peening. Eng Fract Mech2022; 269: 108551. doi:https://doi.org/10.1016/j.engfracmech.2022.108551
18.
QinZLiBChenT, et al. Comparative study of the effects of conventional shot peening and ultrasonic shot peening on very high cycle fatigue properties of GH4169 superalloy. Int J Fatigue2023; 175: 107799. doi:https://doi.org/10.1016/j.ijfatigue.2023.107799
19.
QinZLiBZhangH, et al. Effects of shot peening with different coverage on surface integrity and fatigue crack growth properties of 7B50-T7751 aluminum alloy. Eng Fail Anal2022; 133: 106010. doi:https://doi.org/10.1016/j.engfailanal.2021.106010
20.
BenedettiMPedranzMFontanariV, et al. Enhancing plain fatigue strength in aluminum alloys through shot peening: Experimental investigations and a strain energy density interpretation. Int J Fatigue2024; 184: 108299. doi:https://doi.org/10.1016/j.ijfatigue.2024.108299
21.
SalehnasabBMarzbanradJPoursaeidiE. Conventional shot peening treatment effects on thermal fatigue crack growth and failure mechanisms of a solid solution alloy. Eng Fail Anal2024; 155: 107740. doi:https://doi.org/10.1016/j.engfailanal.2023.107740
22.
LiuBWangBYangX, et al. hermal fatigue evaluation of AISI H13 steels surface modified by gas nitriding with pre- and post-shot peening. Appl Surf Sci2019; 483: 45–51. doi:https://doi.org/10.1016/j.apsusc.2019.03.291
23.
CunninghamBMDLeeringMFanY, et al. Fatigue crack initiation and growth behavior within varying notch geometries in the low-cycle fatigue regime for FV566 turbine blade material. Fatigue Fract Eng Mater Struct2023; 46: 2845–2863. doi:https://doi.org/10.1111/ffe.14036
24.
SoadyKAMellorBGShackletonJ, et al. The effect of shot peening on notched low cycle fatigue. Mater Sci Eng: A2011; 528: 8579–8588. doi:https://doi.org/10.1016/j.msea.2011.08.003
25.
SoadyKAMellorBGWestGD, et al. Evaluating surface deformation and near surface strain hardening resulting from shot peening a tempered martensitic steel and application to low cycle fatigue. Int J Fatigue2013; 54: 106–117. doi:https://doi.org/10.1016/j.ijfatigue.2013.03.019
26.
HeBYSoadyKAMellorBG, et al. Effects of shot peening on short crack growth rate and resulting low cycle fatigue behaviour in low pressure turbine blade material. Mater Sci Technol2013; 29: 788–796. doi:https://doi.org/10.1179/1743284713Y.0000000230
27.
HeBYSoadyKAMellorBG, et al. Fatigue crack growth behaviour in the LCF regime in a shot peened steam turbine blade material. Int J Fatigue2016; 82: 280–291. doi:https://doi.org/10.1016/j.ijfatigue.2015.03.017
28.
HeBYKatsamenisOLMellorBG,et al.3-D analysis of fatigue crack behaviour in a shot peened steam turbine blade material. Mater Sci Eng: A2015; 642: 91–103. doi:https://doi.org/10.1016/j.msea.2015.06.082
