Influence of reverted austenite on static and dynamic mechanical properties of a PH 13-8 Mo maraging steel

Maraging steels are martensitic hardenable steels exhibiting an excellent combination of high strength and adequate toughness. Beside the intermetallic precipitates, reverted austenite, formed during aging, is a decisive microstructural constituent. Static tensile tests showed a pronounced influence of its phase fraction on mechanical properties. Reverted austenite also exhibits a distinctive effect on dynamic properties which were investigated on a split-Hopkinson-pressure-bar. However, reverted austenite is not mechanically stable during external loading and transforms back to martensite. This behavior was investigated by in situ X-ray diffraction using synchrotron radiation. Here, a decreasing phase fraction of austenite with increasing strain was observed. Furthermore, a change of the stability of revered austenite with aging time was noticed.