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公开(公告)号:US11875934B2
公开(公告)日:2024-01-16
申请号:US16423516
申请日:2019-05-28
发明人: Jian-Ping Wang , Md Mehedi , YanFeng Jiang , Bin Ma , Delin Zhang , Fan Zhang , Jinming Liu
CPC分类号: H01F41/0253 , C01B21/0622 , H01F1/10 , C21D2201/05 , C21D2211/008 , C22C38/001 , C22C38/06 , C22C38/16 , C22C2200/04 , C22C2202/02 , H01F1/0009 , H01F1/03
摘要: The disclosure is directed to an iron-nitride material having a polycrystalline microstructure including a plurality of elongated crystallographic grains with grain boundaries, the iron-nitride material including at least one of an α″-Fe16N2 phase and a body-center-tetragonal (bct) phase comprising Fe and N. The disclosure is also directed a method producing an iron-nitride material. The method includes some combinations of preparing a raw material comprising iron, carrying out a microstructure build-up by annealing the prepared raw material at an elevated temperature and subsequently quenching the prepared raw material to produce a microstructure build-up material, annealing the microstructure build-up material, reducing the microstructure build-up material in a hydrogen environment, nitriding the reduced material to produce a nitrided material and subsequently quenching the nitrided material to a martensitic transformation temperature, stress annealing the nitrided material, and magnetic field annealing the stress-annealed material.
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公开(公告)号:US12014853B2
公开(公告)日:2024-06-18
申请号:US17058882
申请日:2019-05-28
发明人: Jian-Ping Wang , Jinming Liu , Bin Ma , Fan Zhang , Guannan Guo , Yiming Wu , Xiaowei Zhang
CPC分类号: H01F1/047 , C01B21/0622 , C23C8/02 , C23C8/26 , H01F41/0253 , C01P2002/60 , C01P2002/72 , C01P2002/77 , C01P2004/02 , C01P2004/03 , C01P2004/04 , C01P2006/42
摘要: In general, the disclosure is directed to bulk iron-nitride materials having a polycrystalline microstructure having pores including a plurality of crystallographic grains surrounded by grain boundaries, where at least one crystallographic grain includes an iron-nitride phase including any of a body centered cubic (bcc) structure, a body centered tetragonal (bct), and a martensite structure. The disclosure further describes techniques producing a bulk iron-nitride material having a polycrystalline microstructure, including: melting an iron source to obtain a molten iron source; fast belt casting the molten iron source to obtain a cast iron source; cooling and shaping the cast iron source to obtain a bulk iron-containing material having a body-centered cubic (bcc) structure; annealing the bulk iron-containing material at an austenite transformation temperature and subsequently cooling the bulk iron-containing material; and nitriding the bulk iron-containing material to obtain the bulk iron-nitride material.
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