A super-duplex stainless steel grade developed for subsea umbilicals, Alleima's latest addition to the range is SAF 3007
With its safe, lighter and stronger avatar, the new tube is an upgrade from the company's current offering, SAF 2507. The heightened features along with a corrosion resistance capacity makes it especially effective in harsh deepwater environments.
Elaborating on the features of this offshore-specific offering, John Tokaruk, global product manager for umbilical tubing at Alleima, said, “As the market leader in umbilical steel tubing, we often get requests for a material matching SAF 2507 in reliability, but with reduced costs, improved fatigue life and enhanced pressure handling. SAF 3007 (UNS S83072) accomplishes all this with a ‘less is more’ approach. Thinner tube walls, thanks to its superior strength and fatigue properties, results in lower cost per meter. It offers the excellent corrosion resistance of SAF 2507, and a similar microstructure, as well as simplified welding due to thinner walls.”
“To enhance the performance of SAF 2507, we fine-tuned the chemical composition. As a result, SAF 3007 features additional chromium at 30%, reduced molybdenum at 1% and, for the first time, Alleima introduces tungsten at 3.4% to the duplex family of tube alloys. The inclusion of tungsten in preference to molybdenum maintains the corrosion resistance after welding, which is crucial for the umbilical application. Taken together, these properties are ideal for ‘dynamic umbilicals’ that are floating and twisting below the ocean surface with high stress in chloride-rich environments,” said Charlotte Ulfvin, senior researcher at the company.
