Abstract
Thermomechanical treatments for improving tensile strength of 18% Ni maraging steels have been investigated. The thermomechanical treatments applied to the 210kg/ mm2 and 245kg/mm2 grades maraging steels include a) cold rolling and aging, b) cold rolling in preaged conditions with and without subsequent re-aging at about 500°C.
Increases in strength produced by cold rolling and aging are given as a function of the reduction in thickness. The tensile strength in the transvers direction reaches to a peak and then decreases because of the drop in elongation.
The increase in strength produced by cold rolling in the pre-aged conditions is small. However, the tensile strength is greatly increased by the subsequent re-aging. The tensile strength in the transverse direction is remarkably improved by a thermomechanical treatment including preaging at 500°C, cold rolling, and re-aging at about 500°C.
