June 1, 2003 — Researchers at ORNL in collaboration with the Caterpillar Technical Center have developed a new modified cast austenitic stainless steel with significantly more high-temperature performance, durability and reliability than the common commercial grade of that stainless steel - and at the same cost per pound as cast stainless steel. Called CF8C-Plus, development of the new cast steel was driven by the need for more performance and reliability in high-temperature exhaust components for advanced diesel engines for heavy-duty truck applications. However, it is also directly applicable to critical or structural components in a wide range of other applications, including marine diesel engines, industrial gas turbines, microturbines, automotive gasoline engines, natural gas reciprocating engines and advanced, large land-based gas turbines or steam turbines. The new steel was developed by "engineered microstructures," a unique, rapid and practical ORNL alloy design method, derived from using more that 20 years of nanoscale microstructural/microcomposition data from the analysis of the roles of all the various alloying elements in the multitude of complex precipitate phases that form in stainless steels and alloys at high temperatures. This new steel resists failure during creep, mechanical fatigue and especially thermal fatigue, at up to 850C, a 200-degree improvement in performance and reliability over the common grade of such cast steel.