Speaker
Shaojun Liu
(Key Laboratory of Neutronics and Radiation Safety)
Description
China low activation martensitic (CLAM) steel has been selected as the primary structure material of FDS series PbLi blankets for fusion reactors, CN helium cooled ceramic breeder (HCCB) test blanket module (TBM) for ITER and the blanket of other future fusion reactors. Tantalum (Ta) is the essential element for reduced activation ferritic/martensitic (RAFM) steels, and the effect of Ta content is one of the key issues for RAFM steels to be finally applied to fusion reactor. To gain the optimal composition of tantalum for CLAM steel, series works had been done by FDS Team.
In this paper, the effect of Ta content (four ingots with different Ta contents of 0.027 wt%, 0.078 wt%, 0.15 wt% and 0.18 wt%, respectively) on the tensile, impact, creep and fatigue properties of CLAM steel were presented. The ingots with Ta content of 0.027% and 0.18% had a higher tensile strength and fatigue life, though the difference of those between the four ingots was slight. The ingots with Ta content of 0.078% and 0.18% had the lower ductile brittle transition temperature (DBTT) value. The elevation of Ta content caused an obvious increase in creep rupture time of one order of magnitude. Meanwhile the creep rate and fatigue softening rate were all inhibited with the increase of Ta content. The grain distributions, precipitates and dislocation evolution combined with theoretical calculation were analyzed. With Ta content increasing, the content of Ta-rich MX particles increased and the Cr-rich M23C6 carbides reversed. Meanwhile, the grain size became finer. For the ingot with Ta content of 0.027%, the effect of precipitation strengthening of Cr-rich M23C6 carbides was more obvious than fine-grain strengthening. And the MX particles were beneficial to hindering the movement of dislocations which could decrease the creep rate and fatigue softeningrate.
Co-authors
Qunying Huang
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei,Anhui, China)
Shaojun Liu
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei,Anhui, China)
Team FDS
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei,Anhui, China)
Xiangwei Zhai
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei,Anhui, China)
Yanyun Zhao
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei,Anhui, China)
