DOI QR코드

DOI QR Code

Electrochmical Characteristics by Water Cavitation Peening of Cu Alloy

워터캐비테이션피닝된 동합금의 전기화학적 특성평가

  • 김성종 (목포해양대학교 기관시스템 공학부) ;
  • 한민수 (목포해양대학교 기관시스템 공학부) ;
  • 김민성 ((주)디섹)
  • Received : 2012.10.23
  • Accepted : 2012.11.19
  • Published : 2012.11.30

Abstract

Copper alloys are widely used for casting materials including ship's propellers and pump impellers as they provide high corrosion resistance. In addition, the demand for these alloys is increasing with rapid growth of offshore structures and exploitation of various substitute energy sources. However, they require regular maintenance because of erosion and cavitation damages induced by exposure to marine environment at high speed flows for a long period of time. Water cavitation peening have received attention as one of surface modifications for durability improvement of the copper alloys. This is a environment friendly technology without influence of heat and easily applicable to casting materials. In this research, water cavitation peening was employed in distilled water for copper alloy castings as a function of time and evaluation of corrosion resistance was followed in seawater for the modified surface by using electrochemical methods. The result suggests that the water cavitation peening for 2 minutes was found to be the optimal peening parameter in terms of durability and corrosion resistance.

동합금은 내식성이 우수하기 때문에 선박 프로펠러, 펌프 임펠러등 많은 주물재료로 사용되고 있다. 또한 해양구조물 및 대체에너지 산업의 급성장으로 수요가 증가하는 추세이다. 그러나 해수환경에 장시간 노출되어 고속 회전함에 따라 발생되는 침식 및 캐비테이션 손상 때문에 잦은 수리가 요구된다. 이러한 동합금의 내구성을 향상시키기 위해서 표면개질방법의 하나로 워터캐비테이션피닝 기술이 주목받고 있다. 이 기술은 열영향이 없고 환경친화적이며 주물재료에 특히 유용한 기술이다. 따라서 본 연구에서는 주물재료인 동합금을 증류수 중에서 워터캐비테이션피닝을 다양한 시간 변수로 실시하였고, 이후 이 재료를 해수중에서 전기화학적 방법을 통해 개질된 표면의 내식성을 평가하였다. 그 결과 재료의 내구성도 향상되며, 내식성도 우수하게 나타난 조건은 2분동안 워터캐비테이션피닝을 실시한 경우였다.

Keywords

References

  1. Kyeong-Dong Park, Yung-Jin Sin, Dong-Ug Kim, "The effect of shot peening on the corrosion and fatigue crack to SAE5155 steel", Journal of the Korean Society of Marine Engineering, vol. 30, no. 6 pp. 731-739, 2006 (in Korean).
  2. Seong-Jong Kim, Seok-Ki Jang, Koang-Yong Hyun, "Effects of peening time on cavitation characteristics and corrosion resistance by shot peened ALBC3", Proceedings of the 36th Journal of the Korean Society of Marine Engineering, Spring Conference, p. 254, 2012 (in Korean).
  3. Chan-Gi Jung, Kyung-Dong Park, "Effect of compressive residual stress on the high temperature fatigue crack propagation behavior of shot-peened spring steel", Journal of Ocean Engineering and Technology, vol. 16, no. 5, pp. 73-79, 2002 (in Korean).
  4. K. Hirano, K. Enomoto, E. Hayashi, K. Kurosawa, "Effect of water jet peening on corrosion resistance and fatigue strength of type 304 stainless steel", Journal of the Society of Materials Science, vol. 45, no. 7, pp. 740-745, 1996 (in Japanese). https://doi.org/10.2472/jsms.45.740
  5. E. Kunio, H. Katsuhiko, M. Masahito, K. Koichi, S. Hideyo, H. Eisaku, "Improvement of residual stress on material surface by water jet peening", Journal of the Society of Materials Science, vol. 45, no. 7, pp. 734-739, 1996 (in Japanese). https://doi.org/10.2472/jsms.45.734
  6. C. A. Rodopoulos, "The effect surface engineering treatments on the fatigue behaviour of 2024-T351 aluminium alloy" Journal of Materials Engineeing and Performance, vol. 16, pp. 30-34, 2007. https://doi.org/10.1007/s11665-006-9004-0
  7. E. Statnikov. "Physics and mechanism of ultrasonic impact", Ultrasonic, vol. 44, pp. 533-538, 2006 https://doi.org/10.1016/j.ultras.2006.05.119
  8. C. Horsch, V. Schulze, D. Lohe, "Deburring and surface conditioning of micro milled structures by micro peening and ultrasonic wet peening", Microsystem Techn. vol. 12, pp. 691-696. 2006. https://doi.org/10.1007/s00542-006-0087-1
  9. Uh-Joh Lim, Ki-Cheol Jeong and Byoung-Du Yun, "Study on the cavitation damage of cupronickel(70/30) tube for gas absorption refrigeration machine", Journal of the Korean Society of Marine Engineering, vol. 28, no. 2, pp. 332-337, 2004.
  10. Woon-Jae Jung, Heon-Joo Kim, Dong-Ok Kim and Eui-Park Yoon, "A study on the change of properties of Al-bronze due to alloy elements and cooling rate", Journal of the Korean Foundrymen's Society, vol. 8, no. 3, pp. 271-281, 1988 (in Korean).
  11. Min-Sung Kim, Investigation on Durability Improvement in Seawater Environment by Water Cavitation Peening and High Velocity Oxy-fuel Spray Coating Technology for Cu Alloy, Mater's Thesis, Mok-po National Maritime University, 2012 (in Korean).
  12. S. M. Hong, M. K. Lee, G. H. Kim, K. H. Kim, W. W. Kim and S. I. Hong. "Improvement of the resistance to cavitation erosion by the formation of $\beta$' martensite in flame-quenched Cu-9Al-4.5Ni-4.5Fe alloys", Journal of the Korean Institute of Surface Engineering. vol. 37, no. 4, pp. 234-241, 2004 (in Korean).
  13. Stefanie Hanke, Alfons Fischer, Matthias Beyer and Jorge dos Santos, "Cavitation erosion of NiAl-bronze layers generated by friction surfacing", Wear, vol. 273, pp. 32-37, 2011. https://doi.org/10.1016/j.wear.2011.06.002
  14. Y. Sekine and H. Soyama, "Evaluation of the surface of alloy tool steel treated by cavitation shotless peening using an eddy current method", Surface & Coatings Technology, vol. 203, pp. 2254-2259, 2009. https://doi.org/10.1016/j.surfcoat.2009.02.018
  15. H. Soyama and N. Yamada, "Relieving micro-strain by introducing macro-strain in a polycrystaline metal surface by cavitation shotless peening", Materials Letters, vol. 62, pp. 3564-3566, 2008. https://doi.org/10.1016/j.matlet.2008.03.055
  16. Seong-Jong Kim, Jae-Yong, Ko and Min-Su Han, "Evaluation of the characteristics using slow strain rate tests of 5456 Al-Mg alloy for ship construction", The Korean Journal of Chemical Engineering, vol. 23, no. 6, pp. 1028-1033, 2006. https://doi.org/10.1007/s11814-006-0025-z
  17. C. Deslouls, D. Festy, O. Gil, G. Ruis, S. Touzain and B. Tribollet, "Characterization of calcareous deposits in artificial sea water by impedance techniques-1. Deposit of $CaCO_3$ without $Mg(OH)_2$", Electrochimica Acta, vol. 43, pp. 1891-1901, 1998. https://doi.org/10.1016/S0013-4686(97)00303-4