研究了Ｆｅ－２５Ｃｕ、Ｆｅ－５０Ｃｕ和Ｆｅ－７５Ｃｕ在硫压高于二组元硫化物分解压条件下的高温硫化，并着重于硫化反应产物持征，各合金的腐蚀速率均低于纯铁和铜，其中Ｆｅ－２５Ｃｕ最慢而Ｆｅ－５０Ｃｕ最快。合金形成复杂的硫化膜结构：其外层为两种二凶复合硫化物的细胞混合层；其内层含未被硫化的金属态α（Ｆｅ）相粒子和源于β（Cu)的内硫化物Cu5FeS4.由于金属向外迁移的结果,该区域常有大量孔洞形成.硫向合金内的渗透速率随铜含量和温度的升高面增加.此外,在外/内硫化界面上形成一些纯金属铜颗粒,它们或呈粒状并被硫化物所包裹\或呈胡须状突出于硫化膜之外.就双相合金腐蚀区别于固溶体合金的特性,对所得实验结果进行了讨论.
The sulfidation of two-phase Fe-Cu alloys containing 25, 50 and 75 wt % cop-per has been studied at 500 and 600 C under sulfur pressures higher than those for the disso- ciation of iron and copper sulfides. A special attention has been devoted to the examination of the microstructure of the scales. Fe-25Cu sulfidized at the slowest rates, whereas Fe-50Cu corroded more rapidly than the other two alloys. The scales contained an outer layer of a mixture of two Cu-Fe double sulfides (Cu,FeS, and CuFeS,), plus an inner region of sulfida- tion concerning mainly the Cu-rich P-phase and also of some Fe-rich a-phase forming Cu,FeS, plus large voids, possibly due to outward diffusion of metal cations. The depth of this zone increased with temperature and iron content. Moreover, pure copper metal particles formed at the scale/subscale, as whiskers protruding out of the external scale surface. The results obtained are examined with special reference to the two-phase nature of these alloys.
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