硼酸应用广泛,其对设备腐蚀不容忽视。针对核电站含硼水溶液循环体系中设备顶端腐蚀的实际情况,取304奥氏体不锈钢为研究对象,研究了在给定温度和一定硼浓度水溶液存在下,溶液上方含硼水蒸气对奥氏体不锈钢的腐蚀行为,并将其与相应的溶液腐蚀对比。采用扫描电子显微镜（SEM）、X射线衍射仪（XRD）和X射线光电子能谱仪（XPS）分析了试样表面氧化膜。结果表明：在180 ℃下腐蚀1 200 h后,304不锈钢在含硼水蒸气中的腐蚀程度高于相应含硼水溶液的腐蚀程度;尽管两种环境中的试样表面均形成了双层氧化膜,但在含硼水蒸气中形成的氧化膜表层富铁镍,而在含硼水溶液中形成的氧化膜表层富铬,并用氧化膜形成机理解释了此现象。

With the widespread use of boric acid,the corrosion problem of equipments exposed to boric acid-containing medi-um cannot be ignored.Based on the actual situation of the equipment tip corrosion in the boron-containing solution circulating system of nuclear power plant,the corrosion behavior of 304 austenitic stainless steel exposed to the vapor above boron-con-taining solution at a given temperature and a certain boron concentration was studied,and contrasting the vapor phase corro-sion with the corresponding solution corrosion was also discussed.The oxide films formed on the surface of specimens were characterized by scanning electron microscopy（SEM）,X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS）.The result indicated that the corrosion of 304 stainless steel exposed to boron-containing vapor was more serious than that exposed to boron-containing solution at 180 ℃ when the corrosion test was carried out for 1 200 h.In spite of forming double-layer oxide films on the samples in both boron-containing vapor and solution,it was noted that the surface layer of the oxide film formed in boron-containing vapor was rich in Fe and Ni,while the surface layer of the oxide film formed in boron-containing solution was rich in Cr.This phenomenon was elucidated by the formation mechanism of oxide film.