Fracture Toughness and Stress Corrosion Characteristics of High Strength Maraging Steel

摘要

The effect of heat treatment on the tensile, fracture toughness, and stress corrosion properties of a high strength maraging steel (nominal composition 16.3 Ni-12.87 Co-4.98 Mo-0.78 Ti) is described. A maximum ultimate tensile strength of 323 ksi, combined with a fracture toughness of 62 ksi sq root of in. was achieved. This strength level appears to be the maximum which can be achieved in maraging type steels without decreasing the crack tolerance below that of currently used high strength low alloy steels. Reversion to austenite did not improve either the fracture toughness or stress corrosion resistance relative to completely martensitic microstructures with equivalent strength. (Author)