Effect of long-term service on the precipitates in P92 steel
来源期刊:International Journal of Minerals Metallurgy and Materials2018年第8期
论文作者:Yan-ping Zeng Jin-dou Jia Wen-he Cai Shu-qing Dong Zhi-chun Wang
文章页码:913 - 921
摘 要:The precipitates in P92 steel after long-term service in an ultra-supercritical unit were investigated by field-emission scanning electron microscopy and transmission electron microscopy and were found to mainly consist of M23 C6 carbides,Laves phase,and MX carbonitrides.No Z-phase was observed.M23 C6 carbides and Laves phase were found not only on prior austenite grain boundaries,martensite lath boundaries,and subgrain boundaries but also in lath interiors,where two types of MX carbonitrides—Nb-rich and V-rich particles—were also observed but the "winged" complexes were hardly found.Each kind of precipitate within the martensite laths exhibited multifarious morphologies,suggesting that a morphological change of precipitates occurred during long-term service.The M23 C6 carbides and Laves phase coarsened substantially,and the latter grew faster than the former.However,MX carbonitrides exhibited a relatively low coarsening rate.The effect of the evolution of the precipitate phases on the creep rupture strength of P92 steel was discussed.
Yan-ping Zeng1,Jin-dou Jia1,Wen-he Cai2,Shu-qing Dong2,Zhi-chun Wang2
1. School of Materials Science and Engineering,University of Science and Technology Beijing2. North China Electric Power Research Institute Co.,Ltd.
摘 要:The precipitates in P92 steel after long-term service in an ultra-supercritical unit were investigated by field-emission scanning electron microscopy and transmission electron microscopy and were found to mainly consist of M23 C6 carbides,Laves phase,and MX carbonitrides.No Z-phase was observed.M23 C6 carbides and Laves phase were found not only on prior austenite grain boundaries,martensite lath boundaries,and subgrain boundaries but also in lath interiors,where two types of MX carbonitrides—Nb-rich and V-rich particles—were also observed but the "winged" complexes were hardly found.Each kind of precipitate within the martensite laths exhibited multifarious morphologies,suggesting that a morphological change of precipitates occurred during long-term service.The M23 C6 carbides and Laves phase coarsened substantially,and the latter grew faster than the former.However,MX carbonitrides exhibited a relatively low coarsening rate.The effect of the evolution of the precipitate phases on the creep rupture strength of P92 steel was discussed.
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