氨法脱硫液成分对304不锈钢局部腐蚀发展阶段影响探究

Influence of Ammonia Desulfurization Liquid Components on Localized Corrosion Development Stage of 304 Stainless Steel

通过恒电压模拟闭塞电池和长周期静态模拟点蚀实验研究氨法脱硫浆液主要成分对304不锈钢局部腐蚀发展阶段的影响,并对腐蚀产物和溶液分别进行X射线光电子能谱(XPS)及紫外可见光谱分析。结果表明,氨法脱硫浆液中低浓度(NH_(4))_(2)SO_(4)对304不锈钢局部腐蚀发展具有促进作用,高浓度则具有抑制作用;随着Cl^(-)浓度的增加,不锈钢局部腐蚀加剧;F^(-)与腐蚀产生的金属离子可以形成络合物附着在不锈钢表面以及与Cl^(-)的竞争迁移作用使得F-的存在对不锈钢的局部腐蚀具有一定的抑制作用。

The influence of main components of ammonia desulfurization slurry on the development stage of localized corrosion for 304 stainless steel was studied by means of constant voltage occlusion battery and long-term static pitting corrosion test aiming to simulate the real local corrosion,as well as XPS and UV-VIS spectroscopy to characterize corrosion products and solutions.The results showed that low concentration(NH_(4))_(2)SO_(4)in ammonia desulfurization slurry can promote the effect on localized corro-sion development of 304 stainless steel,while high concentration can inhibit it.With the increase of Cl^(-)concentration,the localized corrosion was intensified.The complex compounds on the surface resulted from the interaction of F^(-)and metal ions,while the competitive migration effect with Cl^(-)made the pres-ence of F^(-)have a certain inhibitory effect on the localized corrosion of stainless steel.