11 wt% 크롬이 함유된 Ti 첨가 페라이트스테인리스강의 입계부식에 미치는 규소의 영향 = Effect of Silicon on Intergranular Corrosion Resistance of Ti-stabilized 11 wt% Cr Ferritic Stainless Steels

다국어 초록 (Multilingual Abstract)

Ti-stabilized 11 wt% Cr ferritic stainless steels (FSSs) for automotive exhaust systems have been experienced intergranular corrosion (IC) in some heat-affected zone (HAZ). The effects of sensitizing heat-treatment and silicon on IC were studied. Time-Temperature-Sensitization (TTS) curves showed that sensitization to IC was observed at the steels heat-treated at the temperature lower than 650oC and that silicon improved IC resistance. The sensitization was explained by chromium depletion theory, where chromium is depleted by precipitation of chromium carbide during sensitizing heat-treatment. It was confirmed with the results from the analysis of precipitates as well as the thermodynamical prediction of stable phases. In addition, the role of silicon on IC was explained with the stabilization of grain boundary. In other words, silicon promoted the formation of the grain boundaries with low energy where precipitation was suppressed and consequently, the formation of Cr-depleted zone was retarded. The effect of silicon on the formation of grain boundaries with low energy was proved by the analysis of coincidence site lattice (CSL) grain boundary, which is a typical grain boundary with low energy.

참고문헌 (Reference)

1 T. Utsunomiya, 68 : 49-, 1993

2 E. Sato, 64 : 13-, 1995

3 E. Almanza, 35 : 3181-, 2000

4 R. Beltran, 45 : 4351-, 1997

5 T. M. Divine, 12A : 2063-, 1981

6 T. Ujiro, 45 : 1192-, 1996

7 A. Miyazaki, 43 : 21-, 2000

8 T. M. Divine, 14A : 1721-, 1983

9 J.-K. Kim, 61 : 1133-, 2009

10 R. A. Mulford, 39 : 32-, 1983

11 L. P. Lozovatskaya, 29 : 462-, 1993

12 M. Kumar, 48 : 2081-, 2000

13 M. Shimada, 50 : 2331-, 2002

14 H. Y. Bi, 49 : 219-, 2003

15 E. A. Trillo, 33 : 1263-, 1998

16 E. A. Trillo, 47 : 235-, 1999

17 H. Kokawa, 52 : 34-, 2000

18 A. Camus, NASA 1975

19 J.-K. Kim, 52 : 1847-, 2010

20 J. D. Fritz, 16 : 57-, 1997

21 김동우, "머플러용 스테인리스강의 내식성에 미치는 열적 산화의 영향" 대한금속·재료학회 46 (46): 652-661, 2008

22 J. K. L. Lai, "Stainless Steels: An introduction and their recent developments" Bentham Science Publishers 57-, 2012

23 J. K. L. Lai, "Stainless Steels: An introduction and their recent developments" Bentham Science Publishers 16-, 2012

24 C. S. Brossia, "Corrosion 98 no 542"