Juliusz Orlikowski

Comparative Electrochemical Analysis of the Passive Layer Cracking Process on Aluminum Alloys Performed by Means of DC and AC Techniques

In this paper the passive layer cracking process that occurs under tensile stresses and anodic polarization conditions on AA1050, AA5052, AA5056, and AA7005 aluminum alloys was examined by means of direct current (dc) technique, dynamic electrochemical impedance spectroscopy (DEIS), and acoustic emission (AE). Research revealed the advantage of DEIS and AE methods over the dc one. It was also possible to determine the exact moment of the passive layer cracking on investigated aluminum alloys.

Instantaneous Impedance Monitoring of Aluminum Alloy 7075 Corrosion in Borate Buffer with Admixed Chloride Ions

This study presents research capabilities of dynamic electrochemical impedance spectroscopy (DEIS) as a tool used for instantaneous online monitoring of corrosion processes on the example of aluminum alloy 7075. A borate buffer with admixed chloride ions in a quantity ranging from 0.05 mM to 25 mM was used to represent different types of corrosion attack. The surfaces of sample specimens were evaluated before and after the tests by means of scanning electron microscopy. DEIS was assisted in-situ by cyclic polarization and acoustic emission facilitating detection of corrosion attack.

The protection and monitoring of a distribution piping network for potable water supply

Purpose – 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. Design/methodology/approach – 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. Findings – 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...

Development of dynamic method for evaluation of inhibition efficiency on the example of 8-hydroxyquinoline

Abstract Selection of a proper inhibitor should be based on the evaluation of its mechanism and effective concentrations. Mechanism of inhibition usually has dynamic character due to changing physicochemical conditions of the environment and corroding metal surface. Most of actually used methods are stationary or contain assumptions which highly influences obtained values. Development of new dynamic method, based on modified EIS, allows excitation of the system by signal composed of galvanodynamic perturbation and AC signal as a set of 20 sinusoids. Such an approach allowed comparison of the obtained results by two simultaneous methods and verification of the selected electric equivalent circuit. Instant value of charge transfer resistance of mild steel exposed to industrial water with changing concentration of 8-Hydroxyquinoline in the system was determined.

Conducting composites as cable anodes in cathodic protection: a literature summary

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.