摘要
研究了纯钇及合15％和30％（质量分数）Y的Fe－Y合金在硫分压为10－3Pa的H2－H2S混合气中于600—800℃的腐蚀行为．结果表明两种合金的腐蚀速率随着时间而降低，起始阶段后的腐蚀动力学曲线遵循抛物线规律．钇的加入显著降低Fe的腐蚀速率．在实验条件下纯钇形成Y3S3．在三个温度下，合金都形成了FeS外层，其下是含有FeS和Y2S3的混合中间层，而是由α─Fe和Y2S3的细微混合物组成的内硫化区，这是合金中的富Y相经短程扩散分解而成的．在合金／硫化膜的界面内侧没有观察到钇的贫化现象．从二元双相合金系的特征出发。
The corrosion of two iron-based alloys containing 15% and 30% yttrium in H2-H2S mixtures under 10-3 Pa S2 at 600-800℃ was studied to establish whether yttrium additions can improve the sulfidation resistance of pure Fe. the presence of yttrium is beneficial,but not as much as expected. In fact, the corrosion rate of iron is considerably reduced by the yttrium addition, but the two alloys were corroded still much more rapidly than pure yttrium. The sulfidation kinetics of pure yttrium are rather irregular, while the corrosion rate of pure iron and the two alloys tends to become parabolic after an hailal period of variable length. Under all conditions the two alloys form an external FeS layer, overlying an intermediate region of complex composion colltaining a mixture of the compounds of the two metals and an innermost region of internal attack. Thus, iron can still diffuse through the intermediate region to form the outer FeS layer with non-neglible rate. The scaling behavior of these alloys is discussed by taking into account the presence of intermetallic Fe-Y compounds and the limited solubility of yttrium in iron.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
1998年第8期880-887,共8页
Acta Metallurgica Sinica
基金
欧洲共同体资助!CI1-CT94-0007
香港王宽城教育基金
关键词
Fe-Y合金
硫化
腐蚀
Fe-Y alloys, sulfidation, corrosion
