By using carbon particles which are more than an order of magntude smaller than what is typically used to add to steel of researchers at the National Institute for Materials Science in Tsukuba Japan have produced a much stronger steel
By adding just 0.002% carbon to martensitic steel that already contains 9% chromium, Sawada and colleagues were able to increase the time-to-rupture at 923 Kelvin by a factor of 100 over the strongest creep-resistant steel currently available (which contains about 0.08% carbon).
Under constant low-stress loading, and over extended time periods, many materials undergo creep, a permanent deformation that is particularly marked at elevated temperatures. Incorporation of fine particles into metals and alloys, also called dispersion strengthening, is used to impart creep-resistance at high temperatures. A team from Japan's National Institute for Materials Science, Tsukuba, has developed a dispersion strengthening technique that incorporates nanometre-scale carbonitride particles into a martensitic stainless steel (a chromium-containing steel hardened by heat treatment) for improved creep performance.
|Share |||Randall Parker, 2003 July 28 12:52 PM Materials Advances|