Engineers from Sheffield Hallam University are using laser deposition technology to produce Alloy 625, a high-strength material used in the flanges of offshore oil pipelines to stop them corroding.
The researchers — from the university’s Materials and Engineering Research Institute (MERI) — say the method not only reduces material costs by up to 85 per cent, but also cuts down on the amount of nickel used, resulting in a more environmentally friendly production process.
Prof Alan Smith and Dr David Clegg, together with knowledge transfer associate Chunjun Li, are developing the process with Rotherham-based Evenort, a manufacturer of flanges and other pipeline products for the oil and gas industry that have to be machined to tight tolerances from highly alloyed corrosion-resistant materials.
Smith said: ‘We are developing an Alloy 625 process that will give the necessary corrosion resistance but at greatly reduced manufacturing cost. By using laser deposition technology we can clad the flanges with a suitably thick corrosion-resistant layer but, given the complex shape of these products, this is not a straightforward process.
‘The cladding is carried out on the inside surfaces of tubes using powder metallurgy and laser deposition. The savings in terms of materials cost has been estimated to be between 50 and 85 per cent depending on the complexity of the product.’
Smith said this also has an environmental benefit, because far fewer precious metals are required in the manufacturing process.
Craig McKay, general manager for Evenort, added: ‘By applying a laser-deposited section of Alloy 625 to the wetted surfaces of the product, the amount of the costly alloy in the component is much reduced.
‘Flanges produced in this way are therefore cheaper and quicker to market. The savings get bigger as the nominal size of the pipeline increases, so this would be particularly suitable for large-diameter applications such as oil pipelines.’