July 2011 / Volume 63 / Issue 7|
Longus Tool Vita
By Alan Richter, Editor
Long tool life, as the headline states in Latin, benefits every metalcutting application, but especially flying saw ones cutting welded tube in which the machine is already running at the maximum parameters, according to Richard Otter, R&D for ICO Surface Coatings Inc., a division of saw blade manufacturer Tru-Cut Saw Inc. That’s because stopping the operation to change a blade is expensive, he noted.
Courtesy of ICO Surface Coatings
The sawing machine clamps onto a welded tube and travels with the tube to cut it to a specific length, from about 10 ' to 40 ', depending on the customer’s requirements, Otter explained. Stopping the sawing mill can cause $1,000 of scrap steel tubing because of what is called “open seam,” where the rolled steel has not been welded to form the finished product. “If the customer can run the mill longer without tooling changes, this will reduce the amount of scrap tubing they have to recycle and increase profits,” he said.
To increase circular saw blade life 30 to 50 percent vs. the company’s standard multilayer AlTiN coatings, ICO developed ViTA-Nano, a nanocomposite physical vapor deposition coating. “Vita is Latin for life, so this is our extended life coating,” Otter said.
He noted that unlike a multilayer coating in which the coating is deposited in individual steps, the new coating’s four targets (titanium, aluminum titanium, chrome and silicon) are deposited simultaneously. “The cathodes are all turned on at one time,” Otter said.
The ViTA-Nano coating reportedly extends tool life for all carbide tools. “We’ve seen really good adhesion between carbide and this new coating, whereas with HSS the coating seems to be a little bit too hard and has a tendency to flake off,” Otter added.
Compared to AlTiN’s hardness of 3,600 HV, the new coating is 4,500 HV, the company reports. In addition, ViTA-Nano withstands a maximum temperature of 2,200° F vs. 1,650° F for AlTiN, and the former has a 0.45 friction coefficient while AlTiN’s is 0.5. The reduced friction coefficient helps a blade run longer, Otter noted.
In a test sawing 24"×24 "×0.286"-thick, X70-grade oil country tubular goods steel (TGS) with a minimum yield strength of 70 ksi and a minimum tensile strength of 82 ksi, an AlTiN-coated Tru-Cut Saw blade produced 180 cuts (3,879 sq. in.) before failing because of broken teeth. The tests of three sets of ViTA-Nano-coated blades showed tool life increases of 30, 37 and 47 percent before teeth broke: 232 cuts (4,999 sq. in.), 246 cuts (5,301 sq. in.) and 264 cuts (5,689 sq. in.).
For more information about ICO Surface Coatings, Brunswick, Ohio, call (330) 225-3939 or visit www.icosurface coatings.com.
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