The corrosion of steel-based mechanical equipment is a common and everyday occurrence in the CPI. Since the beginning of the 20th century, stainless steel has been used for its resistance to corrosion.
During fabrication and operation, many stainless steel components are exposed to high mechanical loads that create high strains in the material. This may result in the failure of the components at unexpectedly low loads in the presence of corrosive agents.
Grain boundaries play a key role for the combined mechanical and corrosion properties of a stainless material. They serve as sinks for the segregation of impurities that can cause corrosion. The challenge of studying real polycrystalline systems is enormous.
Recently is has been shown that brilliant, high energy x-ray synchrotron radiation can be used to study the local grain structure of a polycrystalline material, including the local stain rate and individual grain orientation under external stress.
The detail of this work is reported in Science, July 18, vol. 321, pp. 349-350 and pp. 382-384. This work is likely to lead to a clearer understanding of stress corrosion cracking and to the development of more corrosion resistant alloys.
Prepared by:
Emory Ford
MTI Associate Director