The NanoSteel Company, a leader in nano-structured steel materials design, has had its Super Hard Steel® (SHS) weld alloy selected by Trimay Wear Plate Ltd to provide wear protection within the steel piping of a concrete slick line at an underground mine in Northern Canada. NanoSteel said that its “superior wear performance has been proven to provide a x30 wear rate improvement over the previous solution.” Combined with Trimay’s unique casing design, this project represents the second line with an identical configuration developed for the customer and will be installed during the first quarter of 2014.
The slick line is a 600 m vertical borehole system of 9 5/8 in diameter casing used for delivering concrete to backfill mined out sections and reinforce rock walls so the next ore body segment can be mined safely. It consists of NanoSteel clad API L80 grade steel casing and Trimay’s proprietary threaded joint system. In its initial installation, thickness loss for the NanoSteel cladding was measured at 0.9 mm, after delivering 120,000 m3 (288,000 t) of concrete over 30 months of service. With this demonstrated wear rate of 320,000 t delivered per mm of thickness loss, the coated pipe has provided a x30 improvement over the previous solution – an uncoated API L80 bare casing with a wear rate of 10,500 t/mm. Service life for the system is projected to achieve full “life of mine” duration, exceeding 19 years.
“The high hardness and toughness properties provided by our weld overlay result in the improved wear performance for this application,” said Tom Santos, Vice President and General Manager of Coatings. “Because of this, a slick line clad with our material eliminates several replacement cycles for a life of mine solution.” Trimay’s Doug Fraser, General Manager, added, “For this vertical slick line application, Trimay’s casing design provides significant time and cost savings at installation. Compared to casing lines with welded flange connections, our threaded joint system connected by a zero-differential coupling can be fitted in the field more than x70 faster and allow a smaller diameter borehole to be drilled at a lower cost.”