• Seisenbacher, Benjamin
• Hofinger, Matthias
• Landefeld, Andreas
• Schnitzer, Ronald
• Leitner, Harald
• Ognianov, Miloslav
• Turk, Christoph

Abstract

<p>Dual hardening steels reach their well-balanced mechanical properties in terms of strength and toughness through the combination of secondary hardening carbide and intermetallic particle precipitation. This characteristic profile makes them well suited for hot-work applications. In this study, out-of-phase thermomechanical fatigue tests, recreating operating conditions present during hot-work applications, were performed on a dual hardening steel and a 5% Cr martensitic hot-work tool steel. Via high resolution analysis utilizing atom probe tomography and transmission electron microscopy, the behaviour of the different precipitate populations under combined thermal and mechanical loading conditions were compared. Coarsening of the different precipitates and partial dissolution of the intermetallic compounds was observed. It could be shown that with rising maximum fatigue test temperature, the dual hardening steel reaches an increased lifetime caused by its higher tempering resistance.</p>

Topics

• compound
• phase
• strength
• carbide
• fatigue
• transmission electron microscopy
• precipitate
• precipitation
• intermetallic
• atom probe tomography
• hot-work steel
• tempering