钛、锰、铌对Fe-25Cr合金在硫化环境中预氧化保护作用的影响

Influence of Ti, Mn,Nb on the Protection of Preformed Oxide Scale of An Fe-25Cr Alloy in the Sulfidation Environment

研究了中等含量的钛（w=4％）、锰（w=9％）或铌（w=8％）对Fe－25Cr合金预氧化层在高温硫化环境中保护性的影响．实验结果发现：所有合金在1000℃，105PaO2中经不同时间预氧化后的硫化均出现了增重缓慢的保护性硫化阶段，之后试样迅速增重．加w（Ti）＝4％使合金形成了略厚的TiO和TiCR2O4混合氧化层，使保护性阶段加长了约1倍；而加W（Mn=9％的合金却形成了多孔的以MnO和MnCR2O4尖晶石相为主的混合氧化层，保护性较差。加铌对Fe－25Cr氧化层的组成及预氧化后的硫化动力学影响甚微．

An investigation on the influence of moderate amount of Ti(4%), Mh(9%) or Nb(8%)(mass fraction) on the protection of prefromed oxide scale of an Fe-25Cr alloy has been carriedout. It has been found that protective sulfidation behaviour appeared in the sulfidation of all alloys after their preoxidation in 105 Pa (O2) at 1 000℃ for various time and, afterwards, rapid weight-gain took place. A thicker scale composed of TiO and TiCr2O4mixtureformed on the 4%Ti containing alloy, resulting a twice longer protective period than Fe-25Cr. A porous oxide scale composed of MnO and MnCr2O4 spinel developed on the 9%Mn adding alloy, which providing rather poor protection. The addition of 8%Nb had little effect on the composition of oxide scale and the subsequent sulfidation kinetics.