摘要
利用自主研发的模拟核电厂二回路高流速工况流动加速腐蚀(FAC)试验装置,研究了A335P11、Q245R、A106Gr.B和A672 Gr.B60等四种压水堆核电厂二回路中常用碳钢/低合金钢在不同配比的乙醇胺(ETA)和氨水(NH3)碱化剂溶液中FAC行为,对比了几种材料的FAC速率和表面腐蚀形貌。结果表明:四种材料初期FAC速率均随着pH的升高和混合碱化剂中ETA含量的增加而逐渐降低;在仅含氨水的溶液中,四种材料FAC速率和表面腐蚀程度均随着材料中Cr含量的降低而逐渐增加,FAC速率从小到大依次为:A335P11<A672Gr.B60<A106BCr.B≤Q245R。而在含有ETA的溶液中,四种碳钢的初期FAC速率均显著降低,未见明显的氧化膜或基体脱落形成的腐蚀坑等冲刷腐蚀形貌。分析表明,混合碱化剂中的ETA通过自身不易挥发和电解能力强等优势,及时调节高温FAC过程中试样表面局部区域的pH波动,维持试样表面较高的pH水平,减缓可溶性Fe2+的生成,降低Fe3O 4氧化膜的溶解度,提高表面氧化膜的完整性和致密度,进而减缓FAC,同时也降低了二回路用碳钢/低合金钢对Cr、Ni和Mo等强化性合金元素的需求。
The high temperature flow accelerated corrosion(FAC)test system was developed independently to simulate the corrosion on carbon steels/low alloy steel by the high velocity secondary water in nuclear power plant.The FAC rates and the surface morphologies of A335P11,Q245R,A106 Gr B and A672 Gr.B60 were compared after FAC testing in alkalizer solutions with different ratio of Ethanolamine(ETA)and NH3.The results show that the FAC rates of the four kind steels all decreased with the increase of pH and the increase of ETA content in the solution.In the“NH3-only”solution,FAC rates increase gradually with the decrease of Cr content,and the FAC rates are as follows,A335P11<A672Gr.B60<A106Gr.B≤Q245R.However,the FAC rates of the four carbon steels all decreased significantly with the introduce of the ETA in the alkalizer solution,and no clear evidence of scalloped or‘orange peel’appearance was observed on the surface,indicating a high FAC resistance in ETA containing alkaline solution.Analysis shows that the ETA in alkaline solution can compensate the local pH fluctuation on the specimen surface and maintain a stable pH level around 9.8.This further suppress the generation of soluble Fe2+and the dissolution of Fe3O 4 oxides,improve the integrity of the surface oxide film and thus reduce the FAC rate.Meanwhile,the demand of Cr,Ni,Mo elements in carbon steels for PWR secondary loop is also reduced.
作者
聂雪超
苗丽
姜磊
鲍一晨
汪家梅
张乐福
张洛凡
王惠
NIE Xuechao;MIAO Li;JIANG Lei;BAO Yichen;WANG Jiamei;ZHANG Lefu;ZHANG Luofan;WANG Hui(Sanmen Nuclear Power Co.Ltd.,Sanmen of Zhejiang 317112,China;Shanghai Nuclear Engineering Research and Design Institute Co.Ltd.,Shanghai 200233,China;Shanghai Jiao Tong University,Shanghai 200240,China;Zhejiang National Inspection Technology Co.Ltd.,Jiaxing of Zhejiang Prov.314300,China)
出处
《核科学与工程》
CAS
CSCD
北大核心
2023年第3期645-652,共8页
Nuclear Science and Engineering
关键词
碱化剂
乙醇胺
流动加速腐蚀
碳钢
Alkalizer
Ethanolamine(ETA)
Flow accelerated corrosion
Carbon steel
