Abstract:Precipitation behavior of chi (χ) phase in the super duplex stainless steel 00Cr25Ni7Mo4N was investigated during an aging process at different temperature from 600℃ to 1000℃ and during an isothermal aging process at 920℃ and 830℃. The backscatter electron detector of SEM was used to examine the amount and distribution of Chi (χ) precipitate. TEM and EDS were used to examine the structure and chemical composition of χ-phase. The results show that the precipitation temperature region of χ-phase is from 750℃ to 920℃, and the peak temperature is about 830 ℃. Comparing with σ-phase precipitation, the amount of χ-phase precipitates is few. The α/γ interfaces and the α/α grain boundaries are the main sites of χ-phase precipitates. During an isothermal aging process, it is found that the precipitation of χ-phase in the 00Cr25Ni7Mo4N steel includes four stages of initiation, rapid precipitation, saturation and transformation into σ-phase. Therefore, the χ-phase is a meta-stable phase, which will gradually transform into the σ-phase after a prolonged aging.
张寿禄,赵泳仙,宋丽强. 超级双相不锈钢00Cr25Ni7Mo4N中χ相时效析出的研究[J]. 钢铁, 2012, 47(2): 72-75.
ZHANG Shou-lu,ZHAO Yong-xian,SONG Li-qiang. Precipitation Behavior of Chi (χ) Phase in Super Duplex Stainless Steel 00Cr25Ni7Mo4N. Iron and Steel, 2012, 47(2): 72-75.