This study was carried out to investigate the effect of W substitution on the precipitation behavior of χ and σ phases in super duplex stainless steel. The χ phase was precipitated at the interface of ferrite / austenite phases and inside the ferrite phase at the initial stage of aging. With an increase in the aging time, the volume fraction of the χ phase increased, and then decreased with the transformation from the χ phase to the σ phase. The σ phase was precipitated later than the χ phase, and the volume fraction of x phase increased with the increase in the aging time. The ferrite phase was decomposed into the new austenite (γ2) and σ phases by aging treatment. The decomposition of the ferrite phase into the γ2 and σ phases was retarded by W substitution for Mo. The volume fraction of the χ phase increased and that of the σ phase decreased due to W substitution. The χ and σ phases were intermetallic compounds, which had lower nickel concentration, and higher chromium, molybdenum, and tungsten concentrations. The χ phase has higher molybdenum and tungsten concentrations than those of the σ phase. The amounts of chromium and nickel in the χ and σ phases did not change, but these phases have higher concentrations of molybdenum and tungsten due to W substitution for Mo.

1. 서 론
2. 실험 방법
3. 실험 결과 및 고찰
4. 결 론
References

• 한현성(한국폴리텍대학 부산캠퍼스) | Huyn-Sung Han
• 김성휘(부경대학교 금속공학과) | Seong-Hwi Kim
• 강창룡(부경대학교 금속공학과) | Chang-Yong Kang Corresponding author