The fracture toughness of a ferrous maraging alloy containing manganese

A Fe-20 pet Co-15 pet Mn-5 pet Mo maraging alloy has been found to exhibit low toughness and brittle fracture throughout its response to age-hardening. Inter granular embrittlement associated with segregation of manganese and with residual oxygen (15 to 300 ppm) in the early stages of aging was replaced by brittle inter-lath separation as aging progressed, the latter mode being associated with intermetallic precipitation and, possibly, the presence of finely-dispersed austenite.