In the article, the results electrochemical study of low-carbon boron steels B27 and 28MCB5 for the delivery state and some states after heat treatment were presented. Following this study the infl uence of heat treatment on the value of electrochemical potential and corrosion rate these steels in an environment of 3% NaCl was defi ned.

In the present work, we report results of investigations of conversion coatings obtaining on magnesium alloy AZ91D by means plasma electrolytic oxidation (PEO) method. Next, on modified alloy surface SiO2−Al2O3 coating was put on. Morphology of obtained coatings, their roughness and corrosion resistant are presented. It was found that coatings obtained by means PEO method and then tighten with ceramic coating show considerable increase of corrosion resistance.

High requirements (high corrosion resistance, frictional wear resistance, and good mechanical properties) for materials in many branches of modern industry can be fulfi lled, using surface engineering methods in particular, developed in recent years, hybrid processes – combining various surface treatments. The paper presents the results of corrosion resistance of nitrided layers with surface zone of nitides ε+γ' (Fe2-3N+Fe4N) on EN X38CrMoV5.1 (WCL) steel treated by chemical phosphating to produce a fine-crystalline and coarse-crystalline zinc phosphate zone and determine their effect on corrosion resistance. In order to determine the corrosion resistance of the composite layer the electrochemical impedance spectroscopy and potentiodynamic test methods were used. The obtained results are discussed in close correlation to the microstructure and morphology of produced layers.

This work presents the results of the influence of electrolytic hydrogenating on the mechanical and chemical properties for the chosen kinds of steal. It was proved that the electrolytic hydrogenating of carbon steels S195 and DC01 in the delivery conditions causes not only changes of the mechanical qualities and the resistance to corrosion, but most of all, it results in creating strong hydrogen galvanic cells.

The effect of the encapsulation of Nd12Fe77Co5B6 powder particles with NiP coating on the surface oxidation rate has been evaluated. The behavior of the composite magnet made of powder after biencapsulation with NiP/epoxyresin layers in solutions with different acidification was also discussed. Evaluation of corrosion resistance of bonded magnets from polarization curves measurements in acidic sulphate solutions (pH = 1 and 3) was carried out. The study showed that the coating of powder particles of NiP layer effectively inhibits the oxidation process of basic alloying elements and reduces the corrosion rate of the final bonded magnets.

The results of corrosion tests of AK64 aluminum alloy under heat-rejecting condition was compared in this article. In order to determine the effect of addition of glycerol to the coolant, on the corrosion resistance of alloy, tests were carried out in two variants. In the first, the corrosion solution was glycol – distilled water. In the second variant, the tests were carried out in a solution of glycol, glycerol and distilled water in a 1:1:2 ratio. Tests was carried out in accordance with the requirements of ASTM D4340 standard. The corrosion products were characterized by scanning electron microscopy and energy-dispersive x-ray spectroscopy. The impact of glycerol addition was studied also by the investigation of mass changes upon the corrosion test. Authors proved the best corrosion resistance of AK64 alloy in the glycol-glycerine-water solution.

The influence of concentration of purine (PU) and adenine (AD) on the corrosion of St3S (SW) carbon steel in acid chloride solution was studied. The inhibition efficiency increases with increase of concentration of both inhibitors. The values of standard free energies of adsorption prove the chemical adsorption of PU and AD according to Langmuir isotherm. The mechanism of formation the protective layer on the surface of the carbon steel was discussed.

The article presents the results of research on chromium-free Ti-containing conversion coatings. The coatings were deposited on zinc substrate from the solution consisted of: K2TiF6, H2O2, Mn(NO3)2, H3PO4 and a film-forming polymer – sodium polyacrylate. The effect of deposition conditions on their morphology (SEM) and corrosion resistance (DC polarization measurements, salt spray test) were investigated. The chemical composition of the coating and the chemical state of each element was determined by X-Ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The results of SEM analysis showed that with increasing deposition time the coating becomes more homogenous. XPS analysis showed that the coating is composed of: Mn, Zn, Ti, P, O and C. Moreover the organic additive is incorporated in the coating after deposition process. The thickness of the selected coating estimated from Auger depth profiling method was less than 100 nm. Coatings deposited from the proposed bath markedly increase the corrosion resistance of bare zinc substrate. The lowest corrosion current density value was recorded for the coating deposited in 60 s.

Unequivocal assessment of cathodic protection effectiveness has been for many years an unsolved technical problem in numerous real cases, e.g. in underground fuel tanks with cathodic protection systems using sacrificial anodes or steel pipelines in very good insulating coatings. In spite of application in such cases of simulating electrodes with the aim of eliminating the IR ohmic voltage drop in potential measurements, assessment has to be performed by an experienced cathodic protection specialist. In the paper the concept has been presented of a measurement device construction, with the aim of eliminating the mentioned drawbacks and allowing use by unqualified personnel.

The article presents the attempt to produce high silicon cast iron based on one-stage and two-stage production process. Based on literature data the unique very good properties of the material (especially resistance to corrosion) were highlighted. Also the issues related to the manufacturing process of casting the material on the basis of experimental work carried out both in industry and laboratory were raised.

In this paper, findings of the corrosion resistance of DC01 steel surface are described. The steel surface was modified with multilayer metallic coatings. Tests were conducted in corrosive medium – body fluids – artificial saliva and artificial blood – SBF. Material was subject to the standard process of the surface preparation before coatings putting. Applying the electrolysis method the multilayer protective layers of the following type were put on DC01 steel used in constructions of medical equipment: nickelnickel- chromium, nickel-chromium, nickel-copper and copper. Examinations included analysis of chemical composition of steel and hardness measurement of base. The structure of outer modified and non – modified layer was determined. Also microscopic metallographic observations, X-ray microanalysis were executed as well as corrosion resistance of particular coatings was determined. The surface modification with metallic coatings caused that the measured densities of corrosive currents of inspected samples evidence the correlation between the Rp value (polarizing resistance) and ikor (density of corrosive current). It was stated that the modification of DC01 steel surface with protective coating nickel-nickel-chromium shows the best anticorrosive properties in intensified corrosion conditions of artificial saliva, whereas in artificial blood the best results gave nickel-copper coating.

In this paper the results of corrosion tests for non-leaded brasses with variable content of tin and nickel were presented. The main aim was the qualitative description of the corrosion process in the dezincification favourable environment. The obtained results enabled the corrosion rate evaluation at different chemical composition of the alloy. Initial conclusions has been formulated on the relations between chemical composition, structure and the corrosion rate for investigated alloys.

In the study an inf uence of nitrided and carbonitrided layers produced by glow discharge method at the temperature of 400oC as well as carbon coating produced at a temperature of 370°C on martensitic steel AISI 420F (3H13 acc. to PN) on corrosion resistance and frictional wear resistance was investigated. Corrosion resistance of produced layers was examined by potentiodynamic method and impedance spectroscopy in 0.5 M water solution of NaCl. Examinations of layer and coating surface morphology and roughness were also made as well as an analysis of surface degredation resulting from corrosion examinations. Phase analysis of the produced diffusive layers was made with a use of X-ray diffractometer while examinations of carbon coating structure were made by Raman spectroscopy. Hardness measurements of the produced layers were also made and frictional wear resistance was tested by the "three rollers-cone" method under unit load of 600 MPa. Investigation results demonstrate a significant influence of nitrided and carbonitrided layers as well as carbon coatings produced in glow discharge conditions on corrosion resistance and frictional wear resistance of AISI 420F steel.

Paper presents the influence of preparation of the surface layer of steel on the nature of the Zn coating and its corrosion resistance. The abrasive blasting (shot and sand blasting) and the chemical treatment (and a multistage treatment – combination of these methods) have been applied in research. Next, the effect of thermal treatment of the material on the formation of Zn coating has been evaluated. Samples covered with quartz sand have been heated to temperature 250oC. Then, hot – dip Zn galvanizing process was performed in industrial conditions. Results of treatment were evaluated basing upon the following parameters: roughness, surface topography and corrosion resistance measured by potentio-dynamic method. Analysis was supplemented by metallographic observations. It was found that the best results of Zn coating were achieved after multistage surface treatment – mechanical combined with chemical.

Results of investigation of the influence of electropolishing, chemical passivation, and annealing of stents made of AISI 316L steel on their roughness and corrosion resistance determined by electrochemical methods are presented.

The work shows the influence of nitrogen, incorporated at the interface between the surface of magnesium alloy and SiO2 coating, on corrosion resistance of AZ91 magnesium alloys. Nitrogen was incorporated before the process of manufacture of protective layers by using the ultra-shallow implantation process of the high frequency plasma (13,56 MHz) in the reactor PECVD. During implantation process was used two types of plasma: N2 and NH3. Then, on each implanted sample was formed the protective coating by the plasma oxidation process or plasma deposition process. The obtained results have been compared with the reference sample. The corrosion properties of formed coatings was established on the basis of the analysis of the voltammetric curves. The lowest value of corrosion current density was obtained for the sample with coating formed in the plasma deposition process connected with N2 plasma implantation process (ikor = 2,36 μA/cm2). The lowest value of pitting corrosion (the largest difference of potentials: the potential of corrosion-resistant Ekor and potential of pitting corrosion Epit) was observed for samples,which the coating produced by plasma oxidation process connected with NH3 plasma implantation process.