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Effects of Boron and Zirconium on Grain Boundary Morphology and Creep Resistance in Nickel-Based Superalloy

  • Byung-Il Kang
  • Cheon-Ha Han
  • Yong-Kwan Shin
  • Jeong-IL Youn
  • Young-Jig KimEmail author
Article
  • 26 Downloads

Abstract

Grain boundaries (GBs) in nickel-based superalloys have a significant influence on the creep resistance of these alloys. In this study, the trace elements of boron and zirconium were added to the newly designed LESS 1 (Ni-22Cr-20Co-2W-2Nb-1.5Al-1.5Ti-0.03C) alloy, and their effects on the GB precipitation behaviors of carbides were observed. The combined addition of boron and zirconium generates a continuous film structure containing MC carbides and M23(C, B)6-type boro-carbides, as well as a grain boundary γ′. Based on the change in microstructure, rupture time is significantly increased. According to the observed microstructures and simulation results, it was confirmed that boron forms M23(C, B)6-type boro-carbides and zirconium appears to stabilize MC carbides at GBs.

Keywords

boron boro-carbide precipitates nickel-based superalloy creep resistance grain boundary zirconium 

Notes

Acknowledgments

This work was supported by the Technology Innovation Program (10052860, Development of Superalloys and Manufacturing Technologies for the Rotor/Casing of the 700 °C grade HSC Steam Turbine), which is funded by the Ministry of Trade, industry, and Energy (MI, Korea).

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Copyright information

© ASM International 2019

Authors and Affiliations

  • Byung-Il Kang
    • 1
  • Cheon-Ha Han
    • 1
  • Yong-Kwan Shin
    • 1
  • Jeong-IL Youn
    • 1
  • Young-Jig Kim
    • 1
    Email author
  1. 1.School of Advanced Materials Science and EngineeringSungkyunkwan UniversitySuwonRepublic of Korea

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