Abstract
Tensile properties and resistivity changes during isothermal aging have been investigated on Fe-Ni-Al maraging steels with and without about 0.4% molybdenum. Nickel content was varied from 10 to 17.5%, and aluminum contents were about 1.5 and 2.5%.
Cellular precipitation was found to be completely suppressed by the addition of 0.4% molybdenum. When cellular precipitation progressed, strength decreased with the increase in ductility (reduction of area). Ductility tended to increase by the rise in aging temperature, or by lengthening aging time. However, it was found that the increase in ductility became difficult with the increase in aluminum content or with the decrease in nickel content. The lack in ductility was considered to be connected with the difficulty to cross-slip.
