论文部分内容阅读
本文研究了Ni16Cr,Ni16Cr3AI、Ni16Cr3Ti及Ni16Cr2Nb等合金在700℃,常压下于O_2-10％(SO_2+SO_3)环境条件下硫化-氧化行为.通过X-射线衍射及扫描电镜技术对腐蚀产物组成及形貌进行了观察。在含有SO_3的情况下,Nil6Cr合金腐蚀速度较快,加入2％的Nb,对其抗腐蚀性能无太大影响,加入3％的Al或Ti时的腐蚀速度明显下降。主要腐蚀产物以初始合金表面为界分为内、外两层。外层是NiO和Ni_3S_2的混合物,内层包括所有合金元素的氧化物和硫化物。整个反应中包含Ni由合金基体向腐蚀产物的外层扩散,以及硫和氧在相反方向上的迁移。腐蚀产物层中传质分析表明,氧化物-硫化物混合产物层的组织形态,对控制整个传质过程起着主要作用。
In this paper, the sulfurization-oxidation behavior of Ni16Cr, Ni16Cr3AI, Ni16Cr3Ti and Ni16Cr2Nb alloys under the environment of O2_2-10% (SO_2 + SO_3) at 700 ℃ under normal pressure was studied. The corrosion products were characterized by X-ray diffraction and scanning electron microscopy And morphology were observed. In the case of SO_3, the corrosion rate of Nil6Cr alloy is faster. When 2% Nb is added, the corrosion resistance of Nil6Cr alloy is not greatly affected. The corrosion rate of Nil6Cr alloy decreases obviously when 3% Al or Ti is added. The main corrosion products to the initial alloy surface is divided into inner and outer layers. The outer layer is a mixture of NiO and Ni_3S_2 and the inner layer includes oxides and sulfides of all the alloying elements. The entire reaction includes the diffusion of Ni from the alloy matrix to the outer layer of the corrosion products and the migration of sulfur and oxygen in the opposite direction. Mass transfer analysis of the corrosion product layer shows that the morphology of the oxide-sulfide mixed product layer plays a major role in controlling the overall mass transfer process.