Development of Castable High-Strength Stainless Steel

QuesTek Innovations has applied its Materials by Design^® approach to develop its Ferrium^® PH48S^TM castable stainless steel. The processing of the alloy has been optimized to enable a good combination of strength, toughness, and corrosion resistance in cast components (~200-220 ksi yield strength, ~220-240 ksi ultimate tensile strength, ~80-90 ksi•√in fracture toughness, salt fog performance similar to PH15-5). The alloy was invented under a United States Marine Corps Small Business Innovation Research grant for application to suspension components of the Expeditionary Fighting Vehicle. Additional test data, including fatigue results, have been developed for application to aerospace components as part of an Air Force-funded project. A review of the design of PH48S, highlights of the current demonstration components, and the properties across cast plates of various section thicknesses will be presented. This versatile alloy enables designers to reduce costs and piece-count through integral designs with high performance.