Poznań University of Technology, Institute of Chemistry and Technical Electrochemistry, ul. Berdychowo 4 60-965 Poznań
Poznań University of Technology, Institute of Chemical Technology and Engineering, ul. Berdychowo 4 60-965 Poznań
PPUH Autopart Jacek Bąk sp. z o.o. ul. Kwiatkowskiego 2A 39-300 Mielec
Institute of Non-Ferrous Metals Division in Poznań ul. Forteczna 12 61-362 Poznań
The paper presents the influence of bisulfate and sulfate ionic liquids additives on the intensity of the corrosion process of PbCaSn alloys. These types of lead alloys are used for grids production by expanded metal technology. Ionic liquids used in presented study contained alkylpyridinium and alkylimidazolium cations. Electrolyte consisted of 37% sulfuric acid with 5 mg cm-3 of particular ionic liquid. Experimental procedure included analysis of potential changes, corrosion current density and polarization resistance determined by DC and AC methods. It has been shown that in the case of bisulfate ionic liquids containing both alkylpyridinium and alkylimidazolium cations, corrosion potential shifts about 200 mV in the direction of more positive values. Moreover, sudden reduction of the corrosion current density and an increase of polarization resistance in values relative to the initial ones have taken place. Analogical effects were not observed for sulphate ionic liquids. The results of the research are creating new perspectives for improvement of the lead-acid batteries performance based on ionic liquids.
Keywords: corrosion, lead acid battery, lead alloys, ionic liquids
2018, Vol. 61, nr 2, s.30-35
Institute of Precision Mechanics, Warsaw, Poland
The paper presents the results of studies of composite layers with nickel matrix and dispersed phase in the form of: alumina oxide (Al2O3) and graphite (Cgraphite) produced by electrodeposition on steel substrate. Three variants of composite layers were produced: Ni/Al2O3, Ni/Cgraphite, Ni/Al2O3/Cgraphite and for comparison purpose a nickel layer was also produced. Alumina oxide and graphite powders were used as dispersion phases. The dispersed phases were characterized by scanning electron microscopy (SEM) and Raman spectroscopy for graphite powder. The results of investigations of the structures of the produced layers with SEM, EDS, and results of Vickers hardness measurements as well as results of corrosion tests using electrochemical potentiodynamic method are presented. Damage characteristics after corrosion studies were obtained using a light microscope.
Keywords: Al2O3, graphite, nickel layers, electrodeposition, hybrid composite layers
2018, Vol. 61, nr 2, s. 36-39
West Pomeranian University of Technology, Szczecin, Faculty of Maritime Technology and Transport
Heat recovery in refinishing spray booths is more and more popular. It is realized with cross recuperators. Despite cleaning the air from overspray particles, sediments of paint are accumulating on fins of the recuperator. The increasing sediment causes the resistance for airflow and heat transfer resistance. This article presents the results of the experiment of analysis of thermal conductivity of sediments. Analyzed samples were collected from the commercially working spray booth. The main goal of the experiment was preliminary assessment of thermal conductivity of overspray sediments.
Keywords: paint overspray sediments, spray booth, heat recovery, thermal conductivity
2018, Vol. 61, nr 2, s. 40-42
Faculty of Civil Engineering, Silesian University of Technology, Gliwice
Institute of Ceramics and Building Materials, Department of Refractory Materials, Gliwice
Complex modernization of building works were carried out in industrial building of unemployed coal mine. Some problems with salt efflorescsnces took place after putting new elevation materials and internal wall plasters. In order to find the reasons of the efflorescences, samples of bricks and mortars were taken and subjected to physical and chemical examinations. Additionally X-ray diffraction analyses were made. Masonry mortars appeared to be less porous and tighter in comparison to bricks. Chemical analyses proved the formation of sulphates and carbonates, having their main source in new mortars sticking new bricks built into. In order to control the efficiency of protective operations of plasters attention were focused into capillary properties among of selected reference materials. The tests proved their resistance in spite of substantial differences in theirs structure in comparison to typical large porous renovation plasters.
Keywords: mortar, plasters, salt efflorescences, pore structure
2018, Vol. 61, nr 2, s. 43-47
CORROSION PROTECTION IN PRACTICE
Repairs of reinforced concrete bridge constructions damaged by chloride corrosion. Part 2
Diagnostyka i Naprawy Konstrukcji, Warszawa
Ways to repair reinforced concrete bridge structures damaged as a result of chloride corrosion of reinforcement are discussed. The most common causes of failure of repair are specified. Recommendations to avoid failures of repair are given.
Part 1 concerns overpass 11T on Marymoncka – Słowackiego Streets over Line T in Warsaw. Part 2 concerns Estakada 26T in Modlińska junction, leading to Jagiellońska Street to the Stefan Grot-Rowecki Bridge in Warsaw.
Keywords: concrete bridges, chloride corrosion, reinforcement corrosion, protection against corrosion of reinforcement, concrete repair
2018, Vol. 61, nr 2, s. 48-51