Neodymium-rich precipitate phases in a high-chromium ferritic/martensitic steel
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- 作者：Yinzhong Shen ; Xiaoling Zhou ; Zhongxia Shang
- 刊名：Metals and Materials International
- 出版年：2016
- 出版时间：May 2016
- 年：2016
- 卷：22
- 期：3
- 页码：459-467
- 全文大小：1,148 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Metallic Materials
Operating Procedures and Materials Treatment - 出版者：The Korean Institute of Metals and Materials, co-published with Springer Netherlands
- ISSN：2005-4149
- 卷排序：22
文摘
Neodymium being considered as nitride forming element has been used in a design of advanced ferritic/martensitic (FM) steels for fossil fired power plants at service temperatures of 630 °C to 650 °C to effectively improve the creep strength of the steels. To fully understand the characteristics of neodymium precipitates in high-Cr FM steels, precipitate phases in an 11Cr FM steel with 0.03 wt% addition of Nd have been investigated by transmission electron microscopy. Three neodymium phases with a face-centered cubic crystal structure and different composition were observed in the steel. They consisted of neodymium carbonitride with an average lattice parameter of 1.0836 nm, Nd-rich carbonitride mainly containing Mn, and Nd-rich MN nitride mainly containing Mn and Co. Other three Nd-rich and Nd-containing phases, which appear to be Nd-Co-Cr/Nd-rich intermetallic compounds and Cr-Fe-rich nitride containing Nd, were also detected in the steel. Nd-relevant precipitates were found to be minor phases compared with M23C6 and Nb/V/Ta-rich MX phases in the steel. The content of Nd in other precipitate phases was very low. Most of added Nd is considered to be present as solid solution in the matrix of the steel.Keywordsalloystemperingmicrostructureprecipitationtransmission electron microscopy (TEM)