ABSTRACT

Ultrahigh strength steels are designed to be used in structural applications where very high loads are applied and often where high strength-to-weight ratios are required. In addition, they must also possess good ductility and toughness. The latter properties have been historically measured by tensile ductility, namely, percent elongation and reduction of area, and by impact resistance or energy absorbed in a notched impact test. However, in recent years the property of fracture toughness has become a significant factor in the acceptance of steels for critical highperformance structural applications.