DIAMOND LIKE CARBON (DLC) COATING ON CARBON STEEL WITH PLASMA TECHNIQUES FOR GAS PIPES

A study about coating on carbon steel by plasma technique aims to determine the variation of time and pressure on the hardness and corrosion strength of a material. The material used in this research was carbon steel with carbon chest of 0.245%. This carbon steel was a plasma technique process with a temperature of 300oC and various pressure variations, such as 1.2 mbar; 1.4 mbar; 1.6 mbar; 1.8 mbar; And 2.0 mbar. The highest hardness was found at 1.8 mbar pressure, which was 161.7 VHN. Then set with a temperature of 300oC and a pressure of 1.8 mbar and a time variation, which were 1 hour; 1.5 hours; 2 hours; 2.5 hours; 3 hours. The largest hardness value was obtained at 3 hours with a hardness value of 161.7 VHN. Then the corrosion test obtained the optimum value at 2 hours with a corrosion value of 0.69 mpy. This was because on the surface of carbon steel there was a layer of Diamond Like Carbon (DLC).

Corrosion Resistance and Mechanical Properties of Carbon Steel under a High Temperature Pressurized Water

The long-term corrosion strength properties for the carbon steels under pressurized water atmosphere have been investigated, in the conjunction with the detailed analysis of their microstructures. The corrosion test for carbon steels was carried out at the temperature of 200°C under a water pressure of 10 MPa. The corrosion test samples were maintained up to 50 weeks in the tube shaped reactor. The mechanical strength and the microstucture of carbon steels suffered from the long term corrosion test were evaluated by SEM, XRD and tensile test. The weight loss of carbon steel by the corrosion test was also examined. The tensile strength of carbon steels decreased with the increase of corrosion time under a pressurized water atmosphere, accompanying the creation of severe corrosion damages like stress corrosion crack.

Complex Carbon-Mineral Sorbents from Common Clay

Carbon/mineral complexes are materials with surfaces covered partially or totally by carbon materials contains. They have high industrial potential uses as material adsorbents and ceramic filters. The objective of this work is to evaluate the corrosion strength in acid and alkaline solutions, and the adsorption capacity of methylene blue of some materials prepared in the LMPSol. The compositions were prepared with an industrial common clay named “taguá” and organic and inorganic additives from industrial residues up to 50%. The corrosion test was performed in water at 60°C and in aqueous solutions of HCl and NaOH at room temperature, with mass losses measured after 15 days. The samples were pressed manually and heated at different temperatures: 110°C, 350°C and 500°C. The performed tests were transverse flexural strength, porosity and water absorption.