Effect of hot isostatic pressing on microstructure and mechanical properties of CLAM steel produced by selective laser melting
Effect of hot isostatic pressing on microstructure and mechanical properties of CLAM steel produced by selective laser melting
复制标题
热等静压对选区激光熔化CLAM钢显微组织和力学性能的影响
DOI：
10.1016/j.jnucmat.2018.12.028
复制
发表时间：
2018
影响因子：
3.1
通讯作者：
Zheng Mingjie
中科院分区：
文献类型：
--
作者：
Zhai Yutao;Huang Bo;Mao Xiaodong;Zheng Mingjie
包层是核聚变反应堆的关键能量转换部件，它设计了大量复杂的嵌入式冷却通道，以消除高核热沉积。由于毡层内部通道结构复杂，毡层组件的制造一直是毡层技术发展的关键问题之一。采用选择性激光熔化（SLM）增材制造（AM）工艺，以中国低活化马氏体（CLAM）钢为材料，制备了小尺寸试验毯模组，并采用热等静压（HIP）工艺改善了测试毯模组的组织和力学性能。研究并评价了SLM建造的CLAM在建造状态、标准热处理状态和HIP&SHT状态下的组织和力学性能。结果表明：与热轧CLAM钢相比，其相对密度达到99.7%；建成状态抗拉强度与建筑方向垂直方向为966.2 MPa，与建筑方向平行方向为829.1 MPa。经过HIP&SHT后，微观组织的取向和不同方向的强度差异减小。垂直和平行于建筑方向的强度值相似，与热轧CLAM钢加SHT的强度值相当。垂直和平行于建筑方向的冲击吸收能量分别从建成状态下的21.02 J增加到9.18 J ，到HIP&SHT状态下的54.48 J和18.83 J 。同时，在HIP的帮助下，微缺陷大幅减少。结果表明，热挤压过程中的位错迁移和再结晶对改善SLM堆焊CLAM钢的组织和力学性能是有效的。
Blanket is the key energy conversion component of a fusion reactor, it is designed with a large number of complex embedded cooling channels to remove the high nuclear heat deposition. Due to the complex inner-channeled structure, the fabrication of the blanket components has been one of the key issues of the blanket technical development. In this study, the selective laser melting (SLM) additive manufacturing (AM) processing was employed to fabricate small scale test blanket module with China low activation martensitic (CLAM) steel, and the hot isostatic pressing (HIP) was applied to improve the microstructure and mechanical properties. The microstructure and mechanical properties of the SLM built CLAM at the as-built, standard heat treatment (SHT) and HIP&SHT status were investigated and evaluated. The results showed that the relative density at the as-built status compared to the hot-rolled CLAM steel reached 99.7%. The tensile strength of the as-built status was 966.2 MPa and 829.1 MPa in the directions vertical and parallel to the building direction, respectively. After the HIP&SHT, the orientation of the microstructure and the difference in strength in different directions decreased. The strength values in the directions vertical and parallel to the building direction were similar, which were equivalent to that of the hot-rolled CLAM steel with SHT. Moreover, the impact absorbed energy in the directions vertical and parallel to the building direction was increased from 21.02 J to 9.18 J at the as-built status to 54.48 J and 18.83 J at the HIP&SHT status, respectively. Meanwhile, micro-defects were drastically decreased with the help of HIP. It could be concluded that the dislocation migration and recrystallization in HIP process is effective to improve the microstructure and mechanical properties of the SLM built CLAM steel.