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在9Cr2WVTa低活化铁素体/马氏体钢中添加合金元素Al和Si,利用SEM,TEM,EPMA和显微硬度计研究了Al和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和Si缩小9Cr2WVTa合金的奥氏体相区,促进d铁素体的生成,且Al元素的影响更加明显.位于马氏体与d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和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℃静态液态Pb-Bi共晶合金中的耐腐蚀性能明显提高,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.
Alloying elements Al and Si were added to 9Cr2WVTa low activation ferrite / martensitic steel. The effects of Al and Si on the microstructure, mechanical properties, impact properties and wear resistance of 9Cr2WVTa steel were studied by SEM, TEM, EPMA and microhardness tester Liquid Pb-Bi eutectic alloy (LBE). The results show that Al and Si reduce the austenite phase of 9Cr2WVTa alloy, promote the formation of d ferrite, and the influence of Al element is more obvious. The M23C6 carbides at the interface between the body and the d ferrite easily generate stress concentration and form holes, severely reducing the room temperature impact properties of the 9Cr2WVTa alloy, and the fracture exhibits brittle fracture characteristics. Through the compound addition of Al and Si, the alloy with better mechanical properties And impact properties of 9Cr2WVTa alloy, the corrosion resistance of the alloy in 550 ℃ static Pb-Bi eutectic alloy is obviously improved because of the formation of Al and Si oxides in the inner layer of the alloy, The compactness of layers reduces the diffusion rate of alloying elements and oxygen.