Papers by Keyword: Pre-Film

Abstract: An environment-friendly pre-film for carbon steel was obtained by using seawater with cerium salt. The influencing factors of cerium salt pre-film were discussed through orthogonal experiments, and the optimum processing parameters were confirmed. Then morphology, composition, the forming process and corrosion resistance of the pre-film were investigated. Analysis by digital microscope showed that the cerium salt pre-film was a blue uniform coating. EDS images displayed that the pre-film consisted of Ce, O and Fe, the major component of the protective layer was a mixture of Ce oxide, Ce hydroxide and Fe hydroxide. The results of electrochemical potentiodynamic polarization and gravimetric measurements indicated that the cerium salt pre-film provided effective protection to the substrate of carbon steel.

Abstract: With the advance of the exploration and development technology, the corrosion problem in oil and natural gas industries has attracted more and more attention due to the appearance of H2S, CO2 and other corrosion medium in the oilfields. 20G steel was used as materials of the gas pipeline in P5 gas field. Corrosion failure of the gathering pipeline of No. 03 well was found in 2009. Therefore, the inhibitor CT2-4 was suggested to be used in the field. The anti-corrosion technology was discussed based on weight loss and electrochemical methods. According to the corrosion environment, the inhibition rate of CT2-4 is higher than 85% when its dosage is more than 125mg/L. The corrosion rate is decreased below 0.076 mm/a. The electrochemical results discover CT2-4 is a mixed-type inhibitor. In order to promote the anti-corrosion efficiency, the pre-film was investigated also. It shows the amount of prefilming and prefilming time are 1250 mg/L and 4h.

Abstract: An update and the latest results on molten metal atomization using a Pressure-Gas- Atomizer will be given. This atomizer combines a swirl-pressure atomizer, to generate a liquid hollow cone film and a gas atomizer to atomize the film and/or the fragments of the film. The paper is focused on powder production, but this atomization system is also applicable for deposition purposes. Different alloys (Sn, SnCu) were atomized to study the characteristics of the Pressure- Gas-Atomizer. The powders produced were analyzed by laser diffraction and image processing. Among other parameters, the molten metal mass flow (~140 – 200 kg/h), the gas mass flow and the atomizer design were varied. The results include the effects of these variances on particle size and particle shape.