A Study on Test Variables Effected on Grain Boundary Etching Test

입계부식시험에 영향을 주는 시험변수에 관한 연구

  • 백승세 (전북대학교 대학원 정밀기계공학과) ;
  • 나성훈 (전북대학교 대학원 정밀기계공학과) ;
  • 이해무 (한국표준과학연구원(KRISS)) ;
  • 유효선
  • Published : 2001.12.01


Recently the non-destructive test technique which uses the grain boundary etching characteristics owing to the variation of material structures has been proposed. However, during in-serviced GEM test there are a lot of variables such as the changes of temperature and concentration of etching solution, the roughness condition of surface polished etc.. The purpose of this paper is to investigate the influences of these test variables on GEM test results in order to establish a reliable and sensitive of GEM evaluation technique. The experiments are conducted in various solution temperatures, 10$\^{C}$, 15$\^{C}$, 20$\^{C}$, and 25$\^{C}$ and in 70% and 100% concentrations of that, and in various surface roughnesses polished by #800, #2000, and 0.3㎛ alumina powder. Through the test with variables, it is verified that the decrease of temperature and concentration of etching solution and the coarsened surface roughness by not using polishing cloth and powder induce some badly and/or greatly influences on GEM test results like grain boundary etching width(W$\_$GB) and intersecting point ratio(N$\_$i/N$\_$0/). Therefore, to get reliable and good GEM test results, it must be prepared the surface of specimen polished by polishing cloth and 0.3㎛ alumina powder and the saturated picric acid solution having 25$\^{C}$ and be maintained the constant temperature(25$\^{C}$) during GEM test.


  1. Burghard, H.C. and McCann, D.R., 1984, 'Fractographic Analysis of a Steam Turbine Disk Failure,' ASTM STP 827, pp. 346-367
  2. EPRI, 1985, 'Manual for Investigation and Correction of Boiler Tube Failures,' pp. 1-110
  3. Viswanathan, R. and Gehl, S.M., 1992, 'Life Assessment Technology for Power-Plant Components,' JOM Feb., pp. 34-42
  4. 靑木滿, 角居好邦, 1994, '火力· 原子力およびプラント機器· 構造部材の經年劣化と壽命豫測,' REALIZE INC., pp. 49-96
  5. 유효선, 송문상, 송기욱, 유대영, 2000, '전기화학적 양극분극시험에 의한 고운 설비부재의 열화손상 평가,' 대한기계학회논문집, 제24권, 제6호, pp. 1398-1407
  6. 淸水健一, 野方文雄, 瀨毛健二, 廣瀨幸雄, 鄭世喜, 1987, '粒界腐植法による石化學フレント用高溫機器の經年劣化評價法,' 日本材料强度學會誌, 第22券, 第3號, pp. 106-114
  7. 김정기, 윤재영, 송기욱, 이주진, 정새희, 1991, '입계부식법에 의한 플랜트용 고온기기의 경년재질열화 평가에 관한 연구,' 대한기계학회논문집, 제15권, 제3호, pp. 898-906
  8. Yu Hyo-Sun, Lim Jae-Kyoo, Chung Se-Hi, 1994, 'A Study on The Stress Corrosion Cracking Evaluation for Weld Joint of Steel by Using Miniaturized Small Specimen,' Journal of KWS, vol. 12, No. 4, pp. 411-423
  9. 송준희, 임재규, 정세희, 1997, '경사기능성/금속 복합재료의 열응력 해석(1)-플라즈마 용사재-,' 대한기계학회논문집, 제21권, 제3호, pp. 439-446
  10. Yu Hyo-Sun, Na Eui-Gyun, Chung Se-Hi, 1999, 'Assesment of Stress Corrosion Cracking Susceptibility by Small Punch Test,' Journal of Fatigue&Fracture of Engineering Materials & Structures, European Structural Integrity Society, Vol. 22, No 10, pp, 889-896