Hardening of reduced activation ferritic/martensitic steels under the irradiation of high-energy heavy-ion

doi:10.7498/aps.66.112501

	Hardening of reduced activation ferritic/martensitic steels under the irradiation of high-energy heavy-ion
	Zhang Chong-Hong2 ; Luo Guang-Nan 1; Song Yin2 ; Zhang Li-Qing2 ; Gou Jie2 ; Ding Zhao-Nan 2; Yang Yi-Tao2
刊名	ACTA PHYSICA SINICA
	2017-06-05
卷号	66 期号:11 页码:9
关键词	reduced activation ferritic/martensitic steel N/Fe-ions irradiation hardening vacancy clusters
ISSN号	1000-3290
DOI	10.7498/aps.66.112501
英文摘要	In order to study the irradiation responses of reduced activation ferritic/martensitic (RAFM) steels which are candidates for fusion reactors, a reduced activation steel is irradiated at a terminal of HIRFL (heavy ion research facility in Lanzhou) with 63 MeV N-14 ions and 336 MeV Fe-56 ions at -50 degrees C. The energies of the incident N/Fe ions are varied from 0.22 MeV/u to 6.17 MeV/u by using an energy degrader at the terminal, so that a plateau region of an atomic displacement damage (0.05-0.2 dpa) is obtained from the near surface to a depth of 24 mu m in the specimens. Nanoindentation technique is used to investigate the nano-hardness changes of the samples before and after irradiation. The constant stiffness measurement is used to obtain the depth profile of hardness. The Nix-Gao model taking account of the indentation size effect (ISE) is used to fit the measured hardness and thus a hardness value excluding ISE is obtained. Consequently, the soft substrate effect for lower energy ion irradiation is effectively avoided. It is observed that there seems to be a power function relationship between the hardness and damage for the RAFM steel. The hardness initially increases significantly with the increase of irradiation damage, then increases slowly when the damage reaches to about 0.2 dpa. Positron annihilation is performed to investigate the defect evolution in the material. The positron annihilation lifetime spectra show that the long-lifetime proportion of the RAFM steel increases significantly after being irradiated. This means vacancy clusters are produced by the irradiation, resulting in the change of mechanics property. Even at low irradiation dose, point defects with high density are generated in the steel specimens, and subsequently aggregate into defect clusters, thereby suppressing the dislocation slip. The defect concentration in the material increases continuously with the increase of irradiation damage, which leads to the obvious irradiation hardening phenomenon. When the damage is higher than 0.1 dpa, the increment of mean lifetime gradually decreases due to the existence of a large number of vacancies and dislocations, and it eventually tends to be saturated, which explains why the irradiation hardening increment rate decreases with the increase of irradiation damage in the material.
资助项目	Joint Funds of the National Natural Science Foundation of China[U1532262] ; National Magnetic Confinement Fusion Program, China[2011GB108003]
WOS关键词	POSITRON-ANNIHILATION ; INDENTATION ; PROFILES ; DAMAGE ; SCALE
WOS研究方向	Physics
语种	英语
出版者	CHINESE PHYSICAL SOC
WOS记录号	WOS:000403091100006
资助机构	Joint Funds of the National Natural Science Foundation of China ; National Magnetic Confinement Fusion Program, China
内容类型	期刊论文
源URL	[http://119.78.100.186/handle/113462/24411]
专题	近代物理研究所_材料研究中心近代物理研究所_能源材料研究组
通讯作者	Zhang Chong-Hong
作者单位	1.Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Peoples R China 2.Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China
推荐引用方式 GB/T 7714	Zhang Chong-Hong,Luo Guang-Nan,Song Yin,et al. Hardening of reduced activation ferritic/martensitic steels under the irradiation of high-energy heavy-ion[J]. ACTA PHYSICA SINICA,2017,66(11):9.
APA	Zhang Chong-Hong.,Luo Guang-Nan.,Song Yin.,Zhang Li-Qing.,Gou Jie.,...&Yang Yi-Tao.(2017).Hardening of reduced activation ferritic/martensitic steels under the irradiation of high-energy heavy-ion.ACTA PHYSICA SINICA,66(11),9.
MLA	Zhang Chong-Hong,et al."Hardening of reduced activation ferritic/martensitic steels under the irradiation of high-energy heavy-ion".ACTA PHYSICA SINICA 66.11(2017):9.