Fragility analysis under low temperature of steel alloy used in helicopter bolt
Fernando Henrique Schild, Vagner Machado Costa, Luciano Volcanoglo Biehl, Pedro Henrique Costa Pereira da Cunha
Abstract
Steels parts used in helicopters are critical in terms of mechanical performance and safety issues where failure can lead to catastrophic consequences. The objective of this study was to evaluate the influence of low temperatures on toughness, through impact testing, on 45NiCrMo16 steel alloy used in the manufacture of bolts used on a helicopter rotor. The aircraft that the studied bolt is used can operate in the Antarctic environment. The temperatures used in the Charpy tests were -40 ºC, -20 ºC, 0 ºC, and 25 ºC. Besides, microstructural analysis (optical and scanning microscopy) and microhardness were done to identify the steel phases/microconstituents and any surface treatment presence. The results showed the presence of a hardened layer, a decrease in impact toughness with decreasing temperature, and a transition from ductile to brittle fracture. The conclusions indicate behavior that can restrict or limit this steel grade application in extreme temperature conditions, that is the ductile-brittle transition region begins from a decrease in temperature starting from -20 ºC.
Keywords
Referências
1 Zhang M, Yang S, Wan F. Competition mechanism of brittle–ductile transition of metals under tensile condition. Mechanics of Materials. 2019;137:103138.
2 Benac DJ, Cherolis N, Wood D. Managing cold temperature and brittle fracture hazards in pressure vessels. Journal of Failure Analysis and Prevention. 2016;16(1):55-66.
3 Yan JB, Liew JYR, Zhang MH, Wang JY. Mechanical properties of normal strength mild steel and high strength steel S690 in low temperature relevant to Arctic environment. Materials & Design. 2014;61:150-159.
4 Kim KJ, Lee JH, Park DK, Jung BG, Han X, Paik JK. An experimental and numerical study on nonlinear impact responses of steel-plated structures in an Arctic environment. International Journal of Impact Engineering. 2016;93:99-115.
5 Lepov VV. Integrity and lifetime in extreme environment of Arctic regions. Procedia Struct Integr. 2018;2019(20):1-3.
6 Mendagaliyev RV, Zadykyan GG, Davletshin AO, Mukashev T, Rashkovets M. Direct laser deposition of coldresistant steels for Arctic shelf development. Materials Today: Proceedings. 2020;30(Pt 3):707-711.
7 Rokilan M, Mahendran M. Sub-zero temperature mechanical properties of cold-rolled steel sheets. Thin-walled Structures. 2020;154:106842.
8 Krstic B, Rebhi L, Ilic N, Dodic M, Dinulovic M, Andric P, et al. Failure of mounting bolt of helicopter main gearbox support strut. Engineering Failure Analysis. 2016;70:351-363.
9 Eliaz N, Gheorghiu G, Sheinkopf H, Levi O, Shemesh G, Ben-Mordechai A, et al. Failures of bolts in helicopter main rotor drive plate assembly due to improper application of lubricant. Engineering Failure Analysis. 2003;10(4):443-451.
10 Lee H-C, Choi J-M, Lee B, Kim T-G. Failure analysis of stress corrosion cracking in aircraft bolts. Engineering Failure Analysis. 2007;14(1):209-217.
11 Fossati M, Pagani M, Giglio M, Manes A. Fatigue crack propagation in a helicopter component subjected to impact damage. Defence Technology. 2020;17(2):416-428.
12 Lourenço NJ, Von Dollinger CFA, Graça MLA, de Campos PP. Failure analysis of the main rotor grip of a civil helicopter. Engineering Failure Analysis. 2005;12(1):43-47.
13 Infante V, Freitas M, Fonte M. Failure analysis of a crankshaft of a helicopter engine. Engineering Failure Analysis. 2019;100:49-59.
14 ASTM International. ASTM E384-17. Standard Test Method for Microindentation Hardness of Materials. West Conshohocken, PA: ASTM International; 2017.
15 ASTM International. ASTM E23-18. Standard Test Methods for Notched Bar Impact Testing of Metallic Materials. West Conshohocken, PA: ASTM International; 2018.
16 Totten GE, editor. Steel heat treatment [Internet]. CRC Press; 2006 [cited 2021 Jan 24]. Available at: https://www.taylorfrancis.com/books/9780849384523
17 Liu B, Wang B, Gu J. Effect of ammonia addition on microstructure and wear performance of carbonitrided high carbon bearing steel AISI 52100. Surface and Coatings Technology. 2019;361:112-118.
18 Dal’Maz Silva W, Dulcy J, Ghanbaja J, Redjaïmia A, Michel G, Thibault S, et al. Carbonitriding of low alloy steels: mechanical and metallurgical responses. Materials Science and Engineering A. 2017;693:225-232.
19 ASM International. Heat treating of irons and steels. In: Dossett JL, Totten GE, editors. ASM Handbook. Vol. 4D. Materials Park: ASM International; 2014. 730 p.
20 ASM International. Steel heat treating fundamentals and processes. In: Dossett JL, Totten GE, editors. ASM Handbook. Vol. 4A. Materials Park: ASM International; 2013. 784 p.
21 Chatterjee A, Chakrabarti D, Moitra A, Mitra R, Bhaduri AK. Effect of deformation temperature on the ductile–brittle transition behavior of a modified 9Cr–1Mo steel. Materials Science and Engineering A. 2015;630:58-70.
22 Kantor MM, Vorkachev KG, Bozhenov VA, Solntsev KA. The microstructure of low carbon microalloyed steel and impact toughness scattering during fracture in ductile-to-brittle transition region. Procedia Struct Integr [Internet]. 2020;30:45-52. http://dx.doi.org/10.1016/j.prostr.2020.12.009.
Submetido em:
24/01/2021
Aceito em:
05/08/2021
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