Corrosion Resistant, Ultra-High Strength, High Toughness Steel

"Current state-of-the-art ferrous products do not provide the desirable combination of ultra-high strength, high toughness as well as good corrosion resistance. For the carrier-based aircraft components, there is the urgent need for such an alloy.Currently that need is met by very-high strength steel with good fracture toughness that is chromium electroplated for good corrosion resistance. However, the process of chromium electroplating is expensive and it uses chemicals that are known humancarcinogens. The current project aims at developing a novel ferrous alloy (using powder metallurgy approach) that would exhibit ultra-high strength, good toughness, and good corrosion resistance without electroplating. The new alloy will develop thedesired property combination through the application of several metallurgical principles such as ultra-fine precipitation of intermetallic compounds, use of chromium to impart corrosion resistance and produce a carbon-free Fe-Ni-Cr type martensiticstructure, ausaging and maraging-type heat treatments to improve strength, solid solution strengthening, and additional strengthening though the inclusion of a small volume of ultra-high hardness precipitates. The success in the project will provide DoDwith a novel stainless steel having ultra-high strength, good toughness, and corrosion resistance properties, with applications in numerous defense and commercial sectors. The successful completion of this p