高温蒸馏坩埚在铅铋合金中的腐蚀行为研究

Study on Corrosion Behavior of High Temperature Distillation Crucible in LBE

针对高温蒸馏处理铅铋合金(LBE)冷却剂中210 Po的坩埚腐蚀行为,在1000℃、5000 Pa条件下开展了材料为金属、氧化物和石墨的坩埚与LBE的静态腐蚀试验,获得了不同材料坩埚试验前后的质量变化、腐蚀试验后LBE中引入的杂质含量、坩埚内外表面及LBE表面形貌的变化以及氧化铝坩埚腐蚀试验后与LBE交界面的金相形貌。结果表明:以石英、氧化铝、氧化锆和钼为材料的坩埚高温下质量稳定;腐蚀试验后,以氧化铝、氧化锆、钼和钨为材料的坩埚引入LBE中的杂质含量小于31 ppm;以氧化铝和氧化锆为材料的坩埚腐蚀试验后内外表面均无腐蚀;氧化铝坩埚与LBE金相界面无腐蚀。综上所述,氧化铝坩埚耐LBE腐蚀性能较好,适宜用作LBE高温蒸馏处理210 Po的蒸馏容器。

Lead-bismuth eutectic(LBE)has excellent physical and chemical properties,it is the coolants of the fourth generation of preferred lead-bismuth reactor and accelerator driven sub-critical system(ADS).Under neutron irradiation condition,LBE produces a large amount of 210 Po,which is an important radioactive material and has important applications in industry,agriculture,aerospace and other fields.210 Po in LBE can be extracted by high temperature distillation technology,in the process,corrosion behavior of distillation crucible is very important.In this paper,the static corrosion test was carried out on 316L stainless steel,molybdenum,tungsten metal materials,quartz,alumina,zirconia,ceramic oxide materials and graphite material crucibles at 1000℃and 5000 Pa,the quality changes of the candidate materials before and after the test were obtained.After the test,the results were got that the impurity content of LBE introduced by candidate crucibles of different materials,the morphology changes of the inner and outer surfaces of the crucibles in addition the surfaces of LBE,the metallographic appearance of the interface between the alumina crucible and LBE.The results show that the graphite crucible is unstable due to the large change of corrosion and carbonization quality.The 316L stainless steel,molybdenum and tungsten crucibles are unstable due to the large changes in corrosion quality.The quality of crucibles made of quartz,alumina,zirconia and molybdenum materials changes little and is stable at high temperature.316L stainless steel,quartz,ceramic and graphite crucibles introduce 49-74 ppm impurities into LBE due to complex components and corrosion,which is relatively large.The high purity of alumina,zirconia,molybdenum and tungsten crucibles introduced in LBE impurity content is less than 31 ppm,which is small.The inner and outer surfaces of 316L stainless steel,molybdenum and tungsten crucibles are seriously corroded and lose metallic luster.The outer surface of graphite crucible is rough and porous,the inner surface is smooth without change.The crucible made of quartz material is cracked by slightly knocking,the outer surface is attached with gray material that is hard to be erased.The inner surface is smooth and clean without change.Part of the outer surface of the ceramic crucible turns brownish red,and the rest remained is unchanges.After the test,the inner and outer surfaces of alumina and zirconia crucibles are smooth without corrosion.The metallographic interface between alumina crucible and LBE is clean without corrosion.To sum up,the alumina crucible has good corrosion resistance to LBE,low price,it is suitable for use as a 210 Po distillation crucible for LBE high-temperature distillation.