TPT May 2014

Technology News

Coating for intricate components HARDIDE Coatings, a specialist in advanced surface coating technology, has developed a new surface engineering technology to protect both internal and external surfaces of components from wear, erosion and acidic corrosion. Using advanced tungsten-carbide based coatings, the company provides engineered solutions to the challenge of increasing critical component lifetime.

Using low temperature chemical vapour deposition (CVD), the coatings can be applied to a wide range of metallic substrates and complex geometries. This is an important development for the tube and pipe industry as the coating could be highly beneficial for small sections of critical components and small diameter pipework. This is particularly true for high-risk areas of systems where problems of abrasion occur, reducing the life of pipes, elbows, pumps, valves, separators and casings. Use of Hardide coatings can increase the lifetime of critical components. CVD coatings are crystallised from the gas phase atom-by-atom, producing a conformal coating that can coat internal and external surfaces and complex shapes. CVD takes place in a vacuum chamber reactor at a temperature of approximately 500°C. The coatings are a metallic tungsten matrix with dispersed nano-particles of tungsten carbide typically between one and ten nanometres in size. Dispersed tungsten carbide nano-particles give the material enhanced hardness that can be controlled and tailored to give a typical range of hardness of between 1,100 and 1,600Hv and, with some types of

Combustion tube being pre-treated for Hardide coating

Hardide coating, up to 3,500Hv. Abrasion resistance is claimed to be up to 12 times better than hard chrome or 500 times better than Inconel. Nano-structured materials are known to possess toughness, crack and impact resistant features. For example, Hardide-Thas proven this bywithstanding 3,000 microstrain deformation without any damage; this deformation will crack or chip most other thick hard coatings. Other key properties include resistance to acids (including H 2 S) and the absence of porosity. The highly mobile reaction products fill pores and defects in the coating as it grows. The porosity, measured as the difference between theoretical and actual material density, is less than 0.04 per cent while the coating completely covers the substrate without any through pores starting from less than 1 micron thickness. Unlike sprayed tungsten carbide, Hardide does

not use cobalt, which can be affected by acids. This is especially important for processing sour oil. A number of Hardide coating variants are offered to solve problems such as severe wear, corrosion or galling. Applications range from topside to downhole including mud pumps, metering, control and shut-off valves, centrifugal and axial pumps, as well as bends, liners, elbow joints and flanges. The coatings can also be used for fracking and drilling tools including mud driven hydraulic parts, rotors, stators and drive parts for turbo-drilling tools. Other successful applications include ejector pumps and combustion tubes for bio-fuel applications.

Hardide Coatings Ltd – UK Fax: +44 1869 353831 Email: info@hardide.com Website: www.hardide.com

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M ay 2014