The mechanical properties of stainless maraging steels

Abstract

1. Maraging Cr−Ni−Mo−Ti steels with around 1% Ti have good ductility and are not susceptible to cracks at high strength levels. These steels are not susceptible to slow fracture in water on prolonged application of static loads close to the ultimate strength and have a high resistance to low-cycle fatigue. In the quenched condition, with the strength ∼100 kg/mm2, the steels have a high impact toughness down to −253°C. 2. Cr−Ni−Mo−Ti steels can be substantially hardened by cold working and aging. The ultimate strength of the steel deformed 50% is equal to that of the quenched steel and the strengthening created by cold working and aging of uncold-worked quenched steel. At higher deformation the effect of aging increases. After cold working and aging the susceptibility to cracking is low at a strength up to 200 kg/mm2. 3. To ensure fairly high mechanical properties the carbon content of maraging Cr−Ni−Mo−Ti steels should be ≤0.03%, and the nickel content should be as high as possible while keeping the steel in the martensitic class.