Tensile Properties of 245 kgf/mm² Grade 18Ni Steel Maraged after Ausaging

Abstract

A study has been made on the precipitation behavior in the austenite region of an 18Ni 245kgf/mm² grade maraging steel. Because of relatively high titanium content, considerable precipitation-hardening is observed in ausaging. Tensile properties of the maraging steel preaged in the austenite region and maraged have also been investigated. The considerable increase in maximum tensile strength after an isothermal maraging is found in the maraging steel preaged in the austenite region. The maraging steel preaged at 550°C shows high tensile properties with good ductility after maraging. However, the maraging steel preaged at 600°C and maraged is less ductile because of relatively coarse precipitates formed at the austenite grain boundaries.