Sacrificial Protection Efficiency Calculations Based on the Results of Stochastically Simulating the Parameters

Unique corrosion conditions in oil refining processes lead to the necessity of using passive and active protection systems, aimed at preventing from damages and ensuring the correct operating conditions of machines. To prevent from the development of corrosion processes on the internal surfaces of horizontal settlers, sacrificial protection is used. Before installing such a protection, they usually calculate the number of protectors to be installed in parallel. Some inputs are stochastic by their nature, which should be considered in assessing the risk of non-achieving the required protection level. The probabilistic model proposed to calculate the parameters of sacrificial tank protection that allows performing an exploratory design based on considering various environmental aspects to decide on the efficiency of sacrificial protection and to assess the achievement of the required protection level.

Hydrogen in Aluminium-Coated Steels Exposed to Synthetic Seawater

Thermally sprayed aluminium (TSA) coatings provide protection to offshore steel structures without the use of external cathodic protection (CP) systems. These coatings provide sacrificial protection in the same way as a galvanic anode, and thus hydrogen embrittlement (HE) becomes a major concern with the use of high strength steels. The effect of TSA on the HE of steel seems to remain largely unknown. Further, the location of hydrogen in TSA-coated steel has not been explored. To address the above knowledge gap, API 5L X80 and AISI 4137 steel coupons, with and without TSA, were prepared and the amount of hydrogen present in these steels when cathodically polarised to −1.1 V (Ag/AgCl) for 30 days in synthetic seawater was determined. One set of TSA-coated specimens was left at open circuit potential (OCP). The study indicates that the amount of hydrogen present in TSA-coated steel is ~100 times more than the amount found in uncoated steel, and that the hydrogen seems to be largely localised in the TSA layer.

“Sacrificial protection in action!”: ultra-high stability of palladesite mineral towards the oxygen reduction reaction

Pd17Se15 nanoparticles have been synthesized by a one-pot colloidal synthesis method. An accelerated degradation test confirms the ultra-high stability of the catalyst which gets enhanced after 50 000 cycles.

Evaluation of Cathodic Protection Criteria for Embedded Steel Reinforcement in concrete structures

This paper presents the results of performance of sacrificial protection in preventing the rebar corrosion in chloride contaminated and chloride free concrete. In this present study, the effectiveness of sacrificial protection of embedded steel rebars has been evaluated on chloride contaminated and chloride free concrete slabs using ribbon type Zinc anodes with ion conductive polymer backfill over a period of 250 days of exposure. The results showed that the ribbon type zinc sacrificial anodes with the navel electrochemical interface (Ion conductive polymer backfill) can confer effective corrosion protection of embedded steel in concrete on preventing corrosion initiation in chloride contaminated as well as chloride free concretes slabs. The cathodic protection criteria evaluated on concrete unit slab showed that 100-150mV is necessary in the atmospheric exposure and 160-200mV under alternate wetting & drying conditions.