公开(公告)号：US20210189537A1

公开(公告)日：2021-06-24

申请号：US17058250

申请日：2019-03-11

Applicant: Hitachi, Ltd.

Inventor： Takahiro ISHIZAKI ,  Yusaku MARUNO ,  Kinya AOTA ,  Yingjuan YANG

IPC: C22C38/58 ,  C22C38/02 ,  C22C38/44 ,  C22C38/48 ,  C22C38/50 ,  C21D6/00

Abstract: An austenitic stainless steel includes a mixed grain structure composed of a columnar crystal having an average crystal grain size of 20 μm or less and an equiaxed crystal having an average crystal grain size of 5.0 μm or less, in which an area proportion of the columnar crystal in the mixed grain structure is 20% or more, and an average crystal grain size of the whole mixed grain structure is 5.0 μm or less. Accordingly, it is possible to provide a material having excellent irradiation resistance and mechanical properties.

公开(公告)号：US20170167005A1

公开(公告)日：2017-06-15

申请号：US15324047

申请日：2015-03-18

Applicant: HITACHI, LTD.

Inventor： Takahiro ISHIZAKI ,  Junya KANEDA

IPC: C22C38/50 ,  B22F3/24 ,  B22F1/00 ,  G21C7/10 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  B22F3/15 ,  C22C38/48

CPC classification number: C22C38/50 ,  B22F1/00 ,  B22F1/0011 ,  B22F3/15 ,  B22F3/24 ,  B22F2003/247 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/48 ,  G21C7/10 ,  G21D1/00

Abstract: An object of the present invention is to provide austenitic stainless steel having a high strength and high corrosion resistance while improving resistance to irradiation and reducing irradiation-induced stress corrosion cracking. A solution is as follows. Austenitic stainless steel of the present invention contains Cr: 16 to 26%, Ni: 8 to 22%, O: 0.02 to 0.4%, C: 0.08% or less, and N: 0.1% or less by weight, and further contains at least one kind of Zr: 0.2 to 2.8%, Ta: 0.4 to 5. 0%, and Ti: 0.2 to 2.6%, the balance being Fe and unavoidable impurities, wherein Zr, Ta, and Ti are precipitated as precipitates of one or more kinds of oxide particles, carbide particles, nitride particles, and composite particles thereof.

公开(公告)号：US20180274053A1

公开(公告)日：2018-09-27

申请号：US15762575

申请日：2016-10-19

Applicant: Hitachi, Ltd.

Inventor： Takahiro ISHIZAKI ,  Yusaku MARUNO

IPC: C21D9/00 ,  C21D6/02 ,  C21D6/00 ,  B22F3/24 ,  B22F3/10 ,  B22F1/00 ,  B22F9/04 ,  C22C38/50 ,  C22C38/48 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  G21C7/10 ,  G21C21/18

CPC classification number: C21D9/0068 ,  B22F1/0014 ,  B22F3/10 ,  B22F3/15 ,  B22F3/20 ,  B22F3/24 ,  B22F9/04 ,  B22F2003/247 ,  B22F2003/248 ,  B22F2301/35 ,  B22F2304/15 ,  B22F2998/10 ,  C21D6/004 ,  C21D6/02 ,  C21D2211/001 ,  C22C32/0026 ,  C22C33/0285 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/02 ,  C22C38/04 ,  C22C38/48 ,  C22C38/50 ,  G21C5/06 ,  G21C5/12 ,  G21C7/10 ,  G21C11/083 ,  G21C21/18 ,  B22F3/14

Abstract: An objective of the invention is to provide an austenitic stainless steel article having superior irradiation resistance and stress corrosion cracking resistance than before while maintaining mechanical properties equivalent to those of conventional ones. There is provided a dispersion strengthened austenitic stainless steel article, including: 16-26 mass % of Cr; 8-22 mass % of Ni; 0.005-0.08 mass % of C; 0.002-0.1 mass % of N; 0.02-0.4 mass % of O; at least one of 0.2-2.8 mass % of Zr, 0.4-5 mass % of Ta, and 0.2-2.6 mass % of Ti; and a balance consisting of Fe and inevitable impurities. The Zr, Ta and Ti components form inclusion particles in the stainless steel article by combining with the C, N and O components. The stainless steel article has an average grain size of 1 μm or less and a maximum grain size of 5 μm or less.