Al和Si对9Cr2WVTa钢力学性能及耐Pb-Bi腐蚀性能的影响  

EFFECTS OF Al AND Si ON MECHANICAL PROPERTIES AND CORROSION RESISTANCE IN LIQUID Pb-Bi EUTECTIC OF 9Cr2WVTa STEEL

作　　者：鲁艳红[1] 宋元元[1] 陈胜虎[1] 戎利建[1] 

机构地区：[1]中国科学院金属研究所中国科学院核用材料和安全评价重点实验室,沈阳110016

出　　处：《金属学报》2016年第3期298-306,共9页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目91226204;中国科学院先导专项基金项目XDA03010304资助~~

摘　　要：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.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 9Cr2 WVTa steels were investigated by SEM, TEM, EPMA and micro hardness tester. The results showed that the addition of Al and Si promoted the formation of d-ferrite, and Al was a much stronger ferrite stabilizer than Si. The presence of d-ferrite significantly degraded the impact toughness of 9Cr2 WVTa steels. M23C6 carbides were observed to precipitate at the d-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.

关 键 词：9Cr2WVTa 冲击性能 AL SI Pb-Bi腐蚀 

分 类 号：TG142.1[一般工业技术—材料科学与工程]