DOI QR코드

DOI QR Code

Inconel 740H 니켈기 초내열합금과 TP316H 스테인리스강의 이종금속 SMA 용접부의 미세조직과 크리프 파단 특성

Microstructure and Creep Fracture Characteristics of Dissimilar SMA Welds between Inconel 740H Ni-Based Superalloy and TP316H Austenitic Stainless Steel

  • 신경용 (창원대학교 신소재공학부) ;
  • 이지원 (창원대학교 신소재공학부) ;
  • 한정민 (두산중공업 기술연구원 소재기술개발팀) ;
  • 이경운 (두산중공업 기술연구원 소재기술개발팀) ;
  • 공병욱 (두산중공업 기술연구원 소재기술개발팀) ;
  • 홍현욱 (창원대학교 신소재공학부)
  • Shin, Kyeong-Yong (Department of Materials Science and Engineering, Changwon National University) ;
  • Lee, Ji-Won (Department of Materials Science and Engineering, Changwon National University) ;
  • Han, Jung-Min (Materials Technology Development Team, Corporate R&D Institute Doosan Heavy Industries & Construction) ;
  • Lee, Kyong-Woon (Materials Technology Development Team, Corporate R&D Institute Doosan Heavy Industries & Construction) ;
  • Kong, Byeong-Ook (Materials Technology Development Team, Corporate R&D Institute Doosan Heavy Industries & Construction) ;
  • Hong, Hyun-Uk (Department of Materials Science and Engineering, Changwon National University)
  • 투고 : 2016.07.25
  • 심사 : 2016.09.12
  • 발행 : 2016.10.31

초록

The microstructures and the creep rupture properties of dissimilar welds between the Ni-based superalloy Inconel 740H and the non-stabilized austenitic stainless steel TP316H have been characterized. The welds were produced by shielded metal arc (SMA) welding process with the AWS A5.11 Class ENiCrFe-3 filler metal, commonly known as Inconel 182 superalloy. Postweld heat treatment at $760^{\circ}C$ for 4 hours was conducted to form ${\gamma}^{\prime}$ strengthener in Inconel 740H. The austenitic weld metal produced by Inconel 182 had a dendritic microstructure, and grew epitaxially from the both sides of Inconel 740H and TP316H base metals. Since both Inconel 740H and TP316H did not undergo any solid-state transformation during welding process, there were no heat-affected-zone (HAZ) sub-regions and the coarsoned grains near the weld interface were limited to a narrow region. The hardness of Inconel 182 weld metal was ~220 Hv. The gradual hardness decrease was detected at HAZ of TP316H, and the TP316H base metal displayed the lowest hardness value (~180 Hv) whilst the Inconel 740H showed the highest hardness value (~400 Hv). Fracture after creep occurred at the center of weld metal, regardless of creep condition. It was found that during creep the cracks initiated and propagated along interdendritic regions and grain boundaries at which Laves particles enriched in Nb, Si and Cr were present. The appropriate design of weld metal was discussed to suppress the creep-induced cracking of the present dissimilar weld.

키워드

참고문헌

  1. R. Viswanathan, K. Coleman and U. Rao, Materials for Ultra-Supercriticla Coal-Fired Power Plant Boilers, Int. J. Pressure Vessels & Piping, 83 (2006) 778-783 https://doi.org/10.1016/j.ijpvp.2006.08.006
  2. T.-U. Kern, K. Wieghardt and H. Kirchner, Material and Design Solutions for Advanced Steam Power Plants, Proc. 4th Int. Conf. on Advances in Materials Technology for Fossil Power Plants, R. Viswanathan et al., ed., ASM International, Materials Park, OH, (2005) 20-34
  3. J.F. Henry, J.D. Fishburn, I.J. Perrin, B. Scarlin, G.N. Stamatelopoulos, R. Vanstone, Advanced Supercritical Technology-A Vital Component of Future Power Generation, Proc. 29th Int. Conf. on Coal Utilization and Fuel Systems, US DOE, ASME, (2004) 1028-1042
  4. W.S. Chang, B.H. Yoon, Y.G. Kweon and G.J. Lee, Improvements in Strength and Weldability of Cr-Mo Steel Plates for Pressure Vessels and Boiler, Journal of KWJS, 20 (2) (2002) 150-159 (in Korean)
  5. S.C. Kim, T.W. Shin, I.J. Moon, B.S. Jang and J. H. Koh, A Study of Characteristics on the Dissimilar Metals (STS 316L-Carbon Steel, ASTM A516-70) Welds made with GTAW, Journal of KWJS, 33 (4) (2015) 345-351 (in Korean)
  6. C. Yan, L. Zhengdong, A. Godfrey, L. Wei and W. Yuqing, Microstructure Evolution and Mechanical Properties of Inconel 740H during Aging at $750^{\circ}C$, Mater. Sci. Eng. A, 589 (2014) 153-164 https://doi.org/10.1016/j.msea.2013.09.076
  7. Y. Chong, Z.D. Liu, A. Godfrey, L. Wang, W. Liu and Y.Q. Weng, Heat Treatment of a Candidate Material for $700^{\circ}C$ A-USC Power Plants, J. Iron Steel Research Int., 22 (2015) 150-156 https://doi.org/10.1016/S1006-706X(15)60023-1
  8. P.F. Tortorelli, K.A. Unocic, H. Wang and J.P. Shingledecker, Ni-Based Alloys for Advanced Ultrasupercritical Steam Boilers, Fossil Energy Crosscutting Research Program Review, US DOE, April 25, Pittsburgh, Pennsylvania, 2015
  9. M. Sireesha, V. Shankar, S.K. Albert and S. Sundaresan, Microstructural Features of Dissimilar Welds between 316LN Austenitic Stainless Steel and Alloy 800, Mater. Sci. Eng. A, 292 (2000) 74-82 https://doi.org/10.1016/S0921-5093(00)00969-2
  10. M. Sireesha, S.K. Albert and S. Sundaresan, Influence of High-Temperature Exposure on the Microstructure and Mechanical Properties of Dissimilar Metal Welds between Modified 9Cr-1Mo Steel and Alloy 800, Metall. Mater. Trans. A, 36A (2005) 1495-1506
  11. K. Laha, K.S. Chandravathi, P. Parameswaran, S. Goyal and M.D. Mathew, A Comparison of Creep Rupture Strength of Ferritic/Austenitic Dissimilar Weld Joints of Different Grades of Cr-Mo Ferritic Steels, Metall. Mater. Trans. A, 43A (2012) 1174-1186
  12. R.L. Klueh J.F. King, Creep and Creep Rupture of ERNiCr-3 Weld Metal, J. Nuclear Mater., 98 (1981) 173-189 https://doi.org/10.1016/0022-3115(81)90398-6
  13. J.M. Gong Y. Jiang and S.T. Tu, Effect of Carbon Migration on Creep Properties of Cr5Mo Dissimilar Welded Joints with Ni-Based and Austenitic Weld Metal, Acta Metallurgica Sinica, 17 (2004) 560-568
  14. A.F. Padilha and P.R. Rios, Decomposition of Austenite in Austenitic Steels, ISIJ International, 42 (2002) 325-337 https://doi.org/10.2355/isijinternational.42.325
  15. H.U. Hong, I.S. Kim, B.G. Choi, Y.S. Yoo and C.Y. Jo, On the Role of Grain Boundary Serration in Simulated Weld Heat-Affected Zone Liquation of a Wrought Nickel-Based Superalloy, Metall. Mater. Trans. A, 43A (2012) 173-181
  16. H.M. Wang, J.H. Zhang, Y.J. Tang and Z.Q. Hu, Rapidly Solidified MC Carbide Morphologies of a Laser-Glazed Single-Crystal Nickel-Base Superalloy, Mater. Sci. Eng. A, 156 (1992) 109-116 https://doi.org/10.1016/0921-5093(92)90421-V
  17. Landolt-Bornstein, Creep Properties of Heat Resistant Steels and Superalloys, Group VIII, Vol. 2, Subvolume B, Springer, 2004
  18. L. Falat, M. Svoboda, A. Vyrostkova, I. Petryshynets and M. Sopko, Microstructure and Creep Characteristics of Dissimilar T91/TP316H Martensitic/Austenitic Welded Joint with Ni-Based Weld Metal, Mater. Charcterization, 72 (2012) 15-23 https://doi.org/10.1016/j.matchar.2012.06.014
  19. J.N. DuPont, C.V. Robino, A.R. Marder and M.R. Notis, Solidification of Nb-Bearing Superalloys, Part II. Pseudoternary Solidification Surfaces, Metall. Mater. Trans. A, 29A (1998) 2797-2806
  20. J.F. Radavich, The Physical Metallurgy of Cast and Wrought Alloy 718, Proc. Conf. Superalloy 718- Metallurgy and Applications, E.A. Loria, ed., TMS, Warrendale, PA, (1989) 229-240
  21. K. Sivaprasad and S. Ganesh Sundara Raman, Influence of Weld Cooling Rate on Microstructure and Mechanical Properties of Alloy 718 Weldments, Metall. Mater. Trans. A, 39A (2008) 2115-2127
  22. M. Sundararaman, P. Mukhopadhyay and S. Banerjee, Some Aspects of the Precipitation of Metastable Intermetallic Phases in Inconel 718, Metall. Trans. A, 23A (1992) 2015-2018
  23. S.I. Kwon, J.H. Do, C.Y. Jo and H.U. Hong, Effect of Post-Weld Heat Treatment on the Microstructure and the Cryogenic Mechanical Properties of Electron Beam Welded Cast Inconel 718, Korean J. Met. Mater., 54 (2016) 29-39 https://doi.org/10.3365/KJMM.2016.54.1.29
  24. S.I. Kwon, S.H. Bae, J.H. Do, C.Y. Jo and H.U. Hong, Charcterization of the Microstructures and the Cryogenic Mechanical Properties of Electron Beam Welded Inconel 718, Metall. Mater. Trans. A, 47A (2016) 777-787