We study the dependence of the ratio of the cathodic protection current to the ultimate diffusion current for Kh70 steel within the range of protective polarization potentials (-0.75)–(-1.05) V (relative to the silver-chloride reference electrode) standardized by the DSTU 4219 in media with different degrees of corrosiveness. It is shown that, within the рН range 5.6–9.6, as the potential shifts to more negative values, the ratio jc.p./jO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {j}_{\mathrm{c}.\mathrm{p}.}/{j}_{{\mathrm{O}}_2} $$\end{document} increases from 0.5 to 138. It was discovered that, for the identical protective polarization potentials in a section of the gas main, the corrosion rate in a defect of the protective coating of steel may not only decrease but also activate the process of hydrogen reduction. It is reasonable to determine a value of the ratio jc.p./jO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {j}_{\mathrm{c}.\mathrm{p}.}/{j}_{{\mathrm{O}}_2} $$\end{document} above which the process of decomposition of soil electrolytes is accelerated and the hydrogenation of the pipe wall in a defect of the coating becomes possible for every medium and take into account this value both in the design of the cathodic protection and in the process of monitoring in the course of operation to prevent stress-corrosion cracking.

中文翻译：

---

介质腐蚀性对KH70管钢阴极保护电流与极限扩散电流比的影响

我们研究了 Kh70 钢在保护极化电位 (-0.75)–(-1.05) V（相对于氯化银参比电极）范围内，阴极保护电流与最终扩散电流之比的相关性，由DSTU 4219 在具有不同腐蚀性的介质中。结果表明，在 рН 范围 5.6-9.6 内，随着电位转移到更多负值，比率 jc.p./jO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage {amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {j}_{\mathrm{c} .\mathrm{p}.}/{j}_{{\mathrm{O}}_2} $$\end{document} 从 0.5 增加到 138。发现，对于同一段气体总管的保护极化电位，钢保护层缺陷处的腐蚀速率不仅会降低，而且会激活氢还原过程。确定比率 jc.p./jO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \ 的值是合理的usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {j}_{\mathrm{c}.\mathrm{p}.