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Results of DC electrochemical measurements of four Ni‐base alloys are presented. The tests were conducted in 1 percent sulphuric acid, containing 0.2 percent chlorides at temperature 353K. Gravimetric test, performed in the same conditions, revealed excellent properties of alloy signed A3. Pitting corrosion of alloy A4 at the test conditions after long exposure at 353K was observed and was confirmed by the applied tests. The multiple anodic polarization (MAP) method is proposed to control alloys’ susceptibility to pitting corrosion.

Results have been presented of investigations on the effect of the temperature change rate on the critical temperature of pitting corrosion. Investigations of 316L stainless steel have been conducted by cyclic thermometry. An increase has been stated of the critical pitting temperature with increase of the temperature change rate. The dependence of the pitting critical temperature is linear in character for all investigated temperature change rates. Values of the critical temperature of pitting corrosion for stationary conditions (E−E_S=0) were obtained by using the extrapolation procedure. The critical pitting temperature obtained by extrapolation practically does not depend on the temperature change rate in the investigated range and is equal to 336.9 K (63.9°C).

The purpose of this paper is to examine the passive layer on 1050A aluminium alloy in non‐stationary conditions of linearly raised and lowered temperatures by means of dynamic electrochemistry impedance spectroscopy (DEIS).

The oxide passive layer on aluminium was examined using DEIS under non‐stationary conditions of linearly raised and lowered temperatures. In total, five heating‐cooling cycles were performed.

A significant change of impedance was observed only during the first cycle, which was called the forming one. During the subsequent cycles, the impedance of the system changed in a reversible manner.

The analysis using a equivalent circuit allowed us to determine a change of electric parameters of the circuit in the temperature function. Obtained changes of the electric parameters were correlated with layer structure.

Results of investigations on a working cathodic protection installation of two underground LPG tanks are presented. The efficiency of anodes and buried reference electrodes were evaluated using electrochemical impedance measurements. On the basis of the impedance spectra obtained it can be shown how one of the anodes attached to the long anode line works inefficiently. In addition, the potential distribution map for the protected tanks is presented. On the basis of this information, an electric connection was revealed from the tanks to the neighbouring reinforced concrete structures, this being inconsistent with the technical guidelines for the cathodic protection installation. The inspection performed on the installation yielded some recommendations concerning the operational parameters and the identification and replacement of defective components.

The basic characteristics of a cathodic protection system, using cable anodes, have been reviewed. Cable anodes differ from typical anode systems because of the anode installation method. An anode system based on cable anodes is not installed in point locations; the anode is located at a small distance from the protected structure and runs in parallel along the route of the structure to be protected. An elastic conducting composite of very good mechanical properties is used as the anode material. This solution can result in a reduction in operating costs, and the avoidance of under‐protected and over‐protected zones, or protective current interference, on other structures.

A method has been proposed for testing rubber linings in industrial conditions based on a proposed model of coating penetration. The depth of penetration of rubber lining by water has been determined on the basis of investigation results by electrochemical impedance spectroscopy. Verification of the proposed procedure has been performed by comparing the obtained results of electrochemical investigations with determination of the water content in rubber by the gravimetric method. It has been confirmed that the values calculated in accordance with the penetration model correlate with the water content in rubber. Investigation results confirm views on the corrosion aggressiveness of media in different zones of a scrubber working as part of the flue gas desulphurisation installation.

The purpose of this paper is to implement the corrosion protection method for steel pipes used in a municipal water-pipe network. Results of an inhibitor protection system installed on the system are presented. Inhibitor protection was required due to the high corrosivity of the water collected by a surface intake, which had resulted in a large number of failures and low water quality, due to the presence of corrosion products.

To assess the effectiveness of protection and to control the optimum dose of the inhibitor dispensed, an automatic system of corrosion monitoring was used, together with an assessment of water corrosiveness based on measurements of physical and chemical properties of water.

Calcium polyphosphate, in the role of a non-toxic corrosion inhibitor, showed significant effectiveness as a anticorrosive and its results were fully noticeable after several years following the commencement of protection. Corrosion monitoring has shown that the effectiveness of inhibitor protection is highest in the summer season, when the water is characterised as being in its most corrosive form.

A reduction in the corrosion rate improves the quality of water and its chemical parameters fall within the standard range for water intended for consumption. The corrosion inhibitor action accelerates the formation of a layer limiting the corrosion rate. In this case, stable corrosion rates may be obtained after only the first year. In terms of the designing systems for monitoring corrosion in water systems, this is very important information as reliable results can be obtained for a long period after the launch of the system.