在9Cr2WVTa低活化铁素体/马氏体钢中添加合金元素Al及Si，研究了Al、Si对9Cr2WVTa钢显微组织、力学性能、冲击性能以及耐液态Pb-Bi共晶合金（LBE）腐蚀性能的影响。结果表明Al、Si缩小9Cr2WVTa合金的奥氏体相区，促进δ铁素体的生成，且Al元素的影响更加明显。位于马氏体与δ铁素体界面的M23C6碳化物处易产生应力集中进而形成孔洞，严重降低9Cr2WVTa合金的室温冲击性能，断口呈现脆性断裂特征。通过Al、Si的复合添加，获得了具有较好力学性能和冲击性能的9Cr2WVTa合金，合金在550℃静态LBE中的腐蚀性能明显提高，其原因在于合金内层氧化层中形成的Al和Si的氧化物，提高了内层氧化层的致密性，降低了合金元素及氧的扩散速率，从而显著提高合金的耐铅铋腐蚀性能。

9Cr2WVTa steel is one kind of reduced activation ferritic/martensitic (RAFM) steels, which are considered as the candidate structural materials for the accelerator driven subcritical system (ADS). Effects of Al and Si on the microstructure, tensile properties, impact toughness and corrosion behavior in liquid lead–bismuth eutectic (LBE) of 9Cr2WVTa steels were investigated. The results showed that the addition of Al and Si promoted the formation of δ-ferrite, and Al was a much stronger ferrite stabilizer than Si. The presence of δ-ferrite significantly degraded the impact toughness of 9Cr2WVTa steels. M23C6 carbides were observed to precipitate at the δ-ferrite grain boundaries, and stress concentrations were created at the carbide/matrix interface, resulting in the intergranular cracking after deformation. Static corrosion tests were conducted in oxygen-saturated LBE at 550 ℃ for 5000 h to study the effects of Al and Si on the corrosion behaviors in LBE. It is shown that the addition of Al and Si improved the corrosion resistance in LBE due to that appreciable enrichments of Al and Si in inner oxide layer increased the compactness of oxide layer and reduced the diffusion rates of alloy elements and oxygen atoms.