Purpose The thermal spraying technique of High-Velocity Oxygen Fuel (HVOF) coating was used to deposit coatings of an alloy composed of Ni-based substrates on stainless steel AISI 304. The aim of this study was to determine the mechanical properties such as hardness and bond strength that these coatings have when the spray distance is varied, as well as the microstructure and phases formed during the thermal spray process. Design/methodology/approach The coatings were applied by HVOF and characterized by scanning electron microscopy, image analysis, X-ray diffraction, microhardness and bond strength to analyze the mechanical properties. Findings The microstructure of the coatings showed low porosity, oxide content and interface contamination in the substrate–coating interface, without the presence of unmolten particles. The microhardness values reached 600 HV for the three spray distances used and the bond strength values reached over 55 MPa. Practical implications The use of coatings on aircraft components is growing dramatically owing to the high costs of advanced materials and the growing lifecycle requirements for high-performance systems, which are taken into account because of the variety of coatings and complexity of environmental factors. Originality/value The originality of this study lies in the development of new coating materials for the manufacture and protection of various turbine components. The value is based on the development of materials and processes to be used to manufacture them.

In the last decades, there have been many researches on the use of ethanol as biofuel, detecting corrosion processes in storage systems, including systems in bioethanol-gasoline blends. This research analyzes the phenomena that occur when exposing the API 5L X-52 steel under stress conditions and presenting the analysis to the susceptibility of the Stress Corrosion Cracking (SCC). The preparation of the test specimens was carried out under the NACE standard TM0177-05, with the results obtained and using the McIntyre diagram the susceptibility of the steel to the SCC was determined; depending on the ductility parameters. The type of fault present in each specimen was identified by Scanning Electron Microscopy (SEM). Under the experimental conditions of the present work, it has concluded that the API 5L-X52 steel exposed in the different study means is not susceptible to Stress Corrosion Cracking.

The objective of this study is to evaluate the effect of adding water at different concentrations (0.5%, 5% and 10%) in ethanol-95% gasoline and 85% (% V) of ethanol in addition to a white medium on the Corrosion Under Stress (CBT) for API 5L X52 steel, typically used in the transportation of hydrocarbons. The tests were performed at a constant rate of extension in a CERT machine at a nominal strain rate of 10-6 s-1. CERT test of simultaneous manner, using the technique of monitoring Electrochemical Noise potential noise and current noise wherein the fluctuations have correspondence with the dissolution of the material. Additionally, it is noted that evidence less in% (V) of the water present is less effective and secondary cracks in the samples analyzed for CBT test results cyclic polarization curves show no tendency to SCC.

The alternative use of ethanol as a biofuel, or total or partial substitute for fossil fuels, has a significant effect when blend with ethanol-gasoline, this addition of gasoline increases the octane number and reduces CO2 emissions from cars. In this study, water concentrations (0.5 and 5%) were used in 10, 85 and 95% (% V) ethanol blends, using the electrochemical linear polarization resistance (LPR) technique in steel pipe API-5L X52. As complementary techniques, pH and conductivity were monitored before and after each test. The objective of this research is to measure the effect of water on the corrosion rate of the ethanol blends. As a result, it was obtained that the solutions with higher water concentration had the highest value of corrosion rate, as well as localized corrosion damage in both cases, which was corroborated by scanning electron microscopy (SEM).

Corrosion problems occur in the petroleum industry in at least three general areas: production, transportation and storage, and refinery operations. In spite of Internal corrosion of product pipelines can be controlled with coatings and inhibitor. The various aggressive agents shall be determined through monitoring of the physical and chemical characteristics of the fluid in contact with the system under study, providing aggressive conditions thereof. The most important elements to be determined are: Gases dissolved in water and gas (H2S, CO2 and O2), Bacteria sulfate-reducing, Chlorides, pH. The aim of this work is make the characterization of the fluid and determinate the corrosivity of them in a transportation pipeline. The results show us the scale of priorization of them as well as a results of the gravimetric techniques.