교류임피던스법에 의한 Nimonic 80A 초내열합금 시효열처리재의 부식거동 고찰

The Corrosion Behavior Study by AC Impedance Method for the Aging Heat Treated Nimonic 80A Superalloy

  • 발행 : 1999.11.01

초록

In this paper the effect of aging heat treatment to the Corrosion behavior for the Nimonic 80A superalloy was studied by AC Impedance methods. Tested solution was 3.5% with tempera-ture $25^{\circ}C$ Electro-chemical corrosion test were carried out for the Nimonic 80A super-alloy which solution heat treated at $1080^{\circ}C$ for 8 hours followed by aging heat treated at $650^{\circ}C,\;700^{\circ}C,\;750^{\circ}C\;800^{\circ}C$ and $850^{\circ}C$ with 16hours under vacuum environment. The obtained results were as follows; 1. Base metal and solution-treated materials were exhibited similar corrosion tendency as Ran-dle equivalent cell. The value of passive film resistance was 579 ohms for the base metal and 124,770 ohms for the solutionized metal such a difference was arose by the ${{\gamma}_^'}$ precipitate on the metal surface during heat treatment. 2. The measure value of $R_p$ for heat-treated at $650^{\circ}C,\;700^{\circ}C,\;800^{\circ}C$and $850^{\circ}C$ were 97,943, 93, 111, 26,961, 15,798 and 11,780ohm respectively. Which indicated that the passive film resistance Rp was reduced as aging temperature increased due to the growth of grain size and sensitization at the grain boundary. 3. The similar tendency was exhibited for corrosion behavior of the electro-chemical corrosion polarization method and AC impedance method and confirmed that AC impedance method was useful tool for corrosion research.

키워드

참고문헌

  1. Corrosion v.51 no.4 R. M. Latanision
  2. Corrosion v.47 no.11 Y. C. Lu(et al.)
  3. Corrosion v.47 no.12 R. Hirayama;S. Haruyama
  4. Corrosion v.48 no.10 C. Gabrielli;M. Keddam
  5. Corrosion v.52 no.11 S. El Haijaii(et al.)
  6. Motorship Special Supplement Max Briner
  7. The Nimonic Alloys(2nd ed.) W.Betteridge(et al.)
  8. The Development of Gas Turbine Materials G.W. Meetham
  9. The Superalloys C. T. Sims(et al.)
  10. 목포해양대학교 논문집 제6집(Ⅰ) 백신영
  11. 목포해양대학교 논문집 제6집(Ⅰ) 나은영
  12. Annual Book of ASTM Standard v.03, 02 ASTM G5-106
  13. International Metals Reviews v.28 no.1 R. Thamburaj(et al.)
  14. Metallurgical Transaction A v.12A no.9 D. A. Grose;G. S. Ansell
  15. Acta Metall v.30 no.2 B. Reppich
  16. v.72 no.8 M. A. Tada;Z. Metallkde
  17. Acta Metall v.33 no.5 C.H.V. Kopezky(et al.)