DOI QR코드

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항공기용 초고장력강(300M) 부품의 가공변질층과 응력부식균열에 관한 연구

A Study of the Affected Layer and Stress Corrosion Crack of Ultra-high-strength Steel (300M) for Aircraft Parts

  • Ahn, Jinwoo (Defense Agency for Technology and Quality) ;
  • Kim, Taehwan (Defense Agency for Technology and Quality)
  • 투고 : 2020.03.05
  • 심사 : 2020.03.30
  • 발행 : 2020.04.30

초록

Mechanical components that support structures in aerospace and power generation industries require high-strength materials. Particularly, in the aerospace industry, aluminum alloys, titanium alloys, and composite materials are increasingly used due to their high maneuverability and durability to withstand low temperature extreme environments; however, ultra-high-strength steel is still used in key components under heavy loads such as landing gears. In this paper, the fault cause analysis and troubleshooting of aircraft parts made of ultra-high-strength steel (300M) broken during normal operation are described. To identify the cause of the defect, a temporary inspection of the same aircraft was performed, and material testing, non-destructive inspection, microstructure examination, and fracture area inspection of the damaged parts were performed. Fracture analysis results showed that a crack in the shape of a branch developed from the tool mark in the direction of the intergranular strain. Based on the results, the cause of fracture was confirmed to be stress corrosion.

키워드

참고문헌

  1. Yoon, Y. W., Park, H. K. and Kim, J. "The Study for Fracture in the First Stage Blade of Aircraft Engine," Journal of the Korean Society for Aeronautical & Space Sciences, Vol 40, No. 3, pp. 806-813, 2018. https://doi.org/10.5139/JKSAS.2018.46.10.806
  2. Lee, G. J., Kim, J. H, "Study for Fracture in the Last Stage Blade of a Low Pressure Turbine," Transactions of the Korean Society of Mechanical Engineers A, Vol. 40, No. 4, pp. 423-428, 2016. https://doi.org/10.3795/KSME-A.2016.40.4.423
  3. Park, K. D., An, J. P., "An Effect of Shot Peening on Corrosion Fatigue Crack Growth of Suspension Material," Transactions of the Korean Society Automotive Engineers, Vol. 14, No. 3, pp. 88-94, 2006.
  4. Lee, K. S., Lee, J. K., Song, K. O., Park, J. H., "Study on Effect of Mechanical Machining and Heat Treatment on Surface Residual Stress of TP316L Stainless Steel," Transactions of the Korean Society of Mechanical Engineers-A, Vol. 35, No. 5, pp. 453-458, 2011. https://doi.org/10.3795/KSME-A.2011.35.5.453
  5. Lee, J. H., Kim, J. S., Kwon, D. H., Park, J. H., Kim, B. M., Jung, Y. H., Kang, M. C., Lee, S. Y., "The Characteristics of Damaged Layer According to Depth of Cut in Micro Endmilling," Journal of the Korean Society of Manufacturing Technology Engineers, Vol. 16, No. 5, pp. 77-83, 2007.
  6. Lee, S. W., Lee, S. G., Shin, J. W., Kim, T. U., Kim, S. C., Hwang, I. H., Lee, J. D., "Fatigue Test and Evaluation of Landing Gear," Transactions of the Korean Society of Mechanical Engineers-A, Vol. 36, No. 10, pp. 1181-1187, 2012. https://doi.org/10.3795/KSME-A.2012.36.10.1181
  7. Nam, T. H., Kwon, M. S., Kim, J. G., "Mechanism of corrosion fatigue cracking of automotive coil spring steel," Metals and Materials International, Vol. 21, No. 6, pp. 1023-1030, 2015. https://doi.org/10.1007/s12540-015-5326-5