Welders Can Breathe Easier with Chromium-Free Alloy, Research Suggests
"We came up with an alloy that is compatible with stainless steel from a corrosion perspective, and a welding process that results in high quality welds,” said John Lippold, professor of materials science and engineering at Ohio State University.
A new alloy designed to lessen welders’ risk of breathing toxic fumes on the job has been developed by two Ohio State University engineers. The alloy is a welding “consumable”—the material that melts under the welder’s torch to fill the gap between parts that are being joined.
Gerald Frankel and John Lippold, professors of materials science and engineering, invented the alloy to aid military and commercial welding personnel who work in tight spaces. Researchers said welds made with the new consumable during tests proved as strong and corrosion-resistant as welds made with commercial stainless-steel consumables. When melted, however, the new alloy did not produce fumes of hexavalent chromium, a toxic form of the element chromium which has been linked to cancer.
Stainless steels contain chromium, but the researchers determined that the consumable alloy that joins stainless-steel parts together doesn’t have to contain the metal. They noted that the use of the new alloy essentially eliminates hexavalent chromium in the welding fumes.
The university has three issued U.S. patents and a pending European patent application covering a series of alloys—based on nickel and copper but with no chromium—all of which can be used with standard welding equipment. The engineers estimated that it would cost five to 10 times more than standard welding consumables, depending on metal prices.
Frankel said that the high cost of the alloy would be justified in situations where ample ventilation may be impossible.
“We came up with an alloy that is compatible with stainless steel from a corrosion perspective, and a welding process that results in high quality welds,” Lippold said. “It is a drop-in replacement for stainless-steel consumables welders use now.”
In the laboratory, the researchers performed electrochemical tests to optimize the composition for corrosion resistance. They also performed mechanical tests of the weld joint to test the alloy’s strength. The new alloy’s performance was comparable to standard commercial welding consumables for stainless steel.
Frankel and Lippold have begun further testing of their alloy with Euroweld Ltd., a manufacturer of specialty welding materials headquartered in Mooresville, N.C. They are also working on ways to lower the cost of the consumable. The university will license the alloy and its applications for commercial development.
The Strategic Environmental Research and Development Program—a partnership of the Department of Defense, the Environmental Protection Agency, and the Department of Energy—funded this research.