Volume 61 (2017): Edizione 3 (July 2017)

This work was focused on changes of corrosion behaviour influence of deformation. The This work focuses on changes in corrosion behaviour under the influence of deformation. The main purpose is to observe the changes caused by tensile stress. The experimental material used is steel 1.4301 and titanium GRADE 2. The measurements were carried out using a potentiostat, which measures potential changes over time and electric current. The electrolyte used was 3.5% NaCl. Corrosion properties, especially polarization resistance, corrosion potential and corrosion rate, were evaluated from the measurements. The results demonstrate the changing corrosion properties depending on deformation. The corrosion properties worsened as the deformation increased.

Tribological properties of Al-brass pipes of various producers were studied in different environments. The tested brasses have very similar chemical composition, but they differ in microstructure due to mainly by heat treatment after cold drawing. Microstructure as well as roughness of surface influence chemical and mechanical properties which are important in operating conditions. The experiments of tribological behavior were made in various environments, dry air, cooling treated water and 3.5 % solution of NaCl at room temperature 21 ± 2°C. The tribological tests were carried out on the Linear Tribometer at normal loading 5 N by the method ball on plate for the duration of 5500 s. The measured friction coefficients were evaluated by the program DIAdem and the diagrams were created from signal generated by software NSignal Express

The article is focused on the possibilities of ultrasound surfaces control on metallic materials by conventional ultrasonic techniques. Physical principles, types of ultrasonic waves to be used for surface control are described in the theoretical part. Three surface control techniques are listed in the experimental part of article. The first technique is a common control by angle ultrasonic probe with using transverse waves. The second technique is surface control by 30-70-70 creep waves and third techniques is surface testing by Rayleigh waves. Practical examples of ultrasonic testing for all techniques are illustrated. The conclusion of the article is devoted to the advantages and limitations of the individual testing methods.

The aim of this work is to describe and analyze corrosion problems and their solutions in oil, gas, and refining industry. Corrosion phenomena and factors influencing them are discussed. Corrosion control and monitoring methods are illustrated. Corrosion management plays vital role in the solving of corrosion problems. The results are summarized in new book of the author “Corrosion Problems and Solutions in Oil Refining and Petrochemical Industry” published by Springer in 2016.

This article is aimed at summarizing knowledge about copper and patina that is formed on the surface of copper. The article describes chemical processes in patina formation and explains the difference between natural and artificial patina, as well as some methods used in the investigation of patina such as XRD analysis, EIS analysis, Raman spectroscopy