利用闭塞电池模型研究硫铵浆液中Q235碳钢局部腐蚀发展情况文献综述
2020-06-06 11:04:15
文 献 综 述 摘要:缝隙腐蚀孔蚀和应力腐蚀破裂有许多共同特征,特征之一是在缝隙、蚀孔内部存 在”闭塞电池”。
由于缝(孔)内外间的对流和扩散受阻,导致闭塞区溶液贫氧、酸化,形成自催化加速腐蚀效应。
另一共同特征是它们只发生在一定 的电位范围内 ,即存在临界电位或保护电位。
临界电位和保护电位指的是外表面电位。
闭塞电池和临界电位是局部腐蚀的两个重要的电化学特征,而它们之间的关系却尚未彻底明了。
这一关系实际上反映了缝(孔)内外间的相互联系。
显然它对于研究局部腐蚀的机理和控制方法有重要意义 . 关键词: 闭塞电池 局部腐蚀 PH Occluded cell model was used to study local corrosion of Q235 carbon steel in harmonium sulfate slurry developments Crevice corrosion pitting corrosion and stress corrosion cracking, there are many common characteristics, one is in the gap, the corrosion inside the hole in the occluded cell. Seam (hole) between the inside and outside the convection and diffusion, leading to poor occlusion area solution oxygen, codification, formed from the catalytic effect of accelerated corrosion. Another common feature is that they only happen within a certain range of potential, is the critical potential or protection potential. Critical potential and protection potential refers to the outer surface potential. Occluded cell and critical potential are the two important electrocardiogram characteristics of local corrosion, and the relationship between them is not completely clear. This relationship is actually reflects the seam (hole) these connections between inside and outside. Obviously it is to study the mechanism of local corrosion and control method has important significance. Keyword: Occluded cell Local corrosion PH 1.闭塞电池的形成 由于胀接部位缝隙内溶液处于滞流状态。
螺旋板式换热器氧只能以扩散的方式向缝内传递。
使缝内的氧耗难以得到补充。
从而使缝隙内的阴极反应中止。