This report presents information on the physical metallurgy, chemical composition, mechanical and physical properties, corrosion resistance, fabrication, and cleaning of several of the newer high-strength stainless steels. The alloys covered include one semiaustenitic precipitation-hardenable stainless steel, PH14-8Mo, and the following martensitic precipitation- hardenable stainless steels: PH13-8Mo, 15-5PH, Custom 455, AM-363, AM-362, and AFC-77. Also included is 17-4PH as a sheet and strip product.

Research and development in the field of high-strength stainless steels appears to be directed along two principal paths: (1) the development of alloys with improved strength properties and (2) the accumulation of information on the properties and physical metallurgy of existing alloys so that they may be used more effectively. By and large, the development of new alloys is being carried out by the stainless-steel producers, while the accumulation of property data for the most part is being undertaken on Government contracts. (Author).

Fracture-toughness testing using principles of fracture mechanics has developed to the point where it can be used as a basis for selection of materials, for estimating limiting design stresses assuming the presence of small flaws, and for analyzing failures. Current methods of measuring plane-stress and plane-strain fracturetoughness parameters are presented in this report. The specimens include center-cracked, edge-cracked, single-edge-cracked, surface-cracked, and notched round bars, which are subjected to tensile loading, and notched bars for bend tests. The different types of specimens permit evaluating sheet, plate, bar stock, and forgings as well as material from failed structures. Application of fracture-toughness parameters to design of high-strength structures is reviewed for both static and fatigue loading. Consideration of the fracture-mechanics concepts in design should lead to fewer problems with brittle fracture in high-strength structures. (Author).