| Popis: |
The general regularities of the influence of temperature (t) of acid solutions on the protection effectiveness of steel in them by organic compounds have been considered. The effectiveness of organic compounds in slowing down the corrosion of steels, as a rule, either decreases with increasing t or passes through a maximum at 60 °C. It was noted that there is a group of high-temperature corrosion inhibitors, the temperature maximum of which lies above 60 °C, that allows them to be used in the protection of steels even in environments with t > 100 °C. The general approaches to the protection of steels in solutions of mineral acids under conditions of high-temperature corrosion (t > 80 °C) with unsaturated organic compounds (UC) and mixtures based on them were analyzed. The use of multicomponent compound containing UC is appropriate for the protection of steels in high-temperature solutions of acids, in some cases at t up to 250 °C. The ability to protect steels at such high t is due to the unique mechanism of the UC inhibitory action, which is the result of their ability to chemisorption on the metal surface and undergo deep chemical transformations leading to the formation of a protective polymer film. Limitations on the use of UC as corrosion inhibitors are associated with their chemical instability in volume of acid, as well as toxicity of UC itself and composite additives used with them. |
