Researchers found that decoupling stress and corrosion in the intergranular cracking of noble alloys would help in eliminating premature failures in engineered structures.
A team of researchers at Arizona State University studied the causes of premature failure of metal structures, including bridges, aircraft, and nuclear power generating plants. They found that intergranular stress-corrosion cracking (SCC) is due to the concurrent occurrence of a tensile stress and corrosion, and could be controlled by decoupling stress and corrosion independently.
The findings was published in the journal Nature Materials on September 10, 2018, the research is titled: “Decoupling the role of stress and corrosion in the intergranular cracking of noble alloys.” The research was supported by the U.S. Department of Energy. The project work on this kind of stress corrosion problem was in operation since the last 30 years. However, this present findings would help the scientists to get a new view on designing alloys to avoid stress corrosion-induced failure.
The team examined the alloys at extreme high temperature and gave a new paradigm that challenges the conventional viewpoint. They observed that concurrent presence of stress and a corrosive environment is not necessary condition for stress-corrosion cracking. The researchers marked that stress-corrosion cracking can happen even if the corrosion occurs before the metal getting exposed to stress. The project was trialed using a laboratory model silver-gold alloy, as it shares the same behavior as that of stainless steel and nickel-base alloys used in nuclear power plants.
The researchers believe that their result would help in identifying new alloys that are resistant to corrosion, which could be used as replacement parts in existing plants and other applications.