Based on the analysis of experimental data from actual engineering , corrosion distribution law of general corrosion was found to follow the lognormal distribution through k - s test , while the localized corrosion follows the extreme distribution of type 根据工程实际检测数据的统计分析,通过k - s检验得出了均匀腐蚀深度服从对数正态分布,局部腐蚀深度服从极值型分布的规律。
Using extremum statistical method to predict pit corrosion sizes of the pipeline in service and further to evaluate the residual strength of the pipeline has a great significance for controlling accidents of corrosive perforations , guiding pipeline rehabilitation and replacement as well as prolonging service life of pipeline 长输管道的腐蚀类型多为均匀腐蚀或点腐蚀,采用极值统计方法对在役管道的点蚀尺寸进行预测,进而评价管道的剩余强度,对于控制管道的腐蚀穿孔事故、指导管道的修复更换、延长管道的使用寿命具有重要意义。
A modified definition of polarization resistance calculated from the equivalent circuit of eis make its value dependent on the grain size . in anodic polarization test ( sweeing and stair - steps ) , the maximum ( critical ) current density increases while the passivation potential and breakdown potential lowers with the reduction of the grain size . fegsem images showed the grain growth and pitting corrosion of the nc copper surface , uniform corrosion in the mc copper surface and the broken passivation layer in both surfaces 在阳极极化实验(包括扫描法和台阶法)中,致钝电流虽晶粒尺寸减小而增大,而致钝电位和击穿电位都随着晶粒细化而降低。 fegsem照片发现了纳米晶铜的晶粒长大和孔蚀,微米晶铜表面的均匀腐蚀,和两种铜表面破碎的钝化膜。