Oxidation and Corrosion Effects on Thermal Fatigue Behaviour of Hot Work Tool Steel X38CrMoV5 (AISI H11)

Pascal Lamesle (1) , Mehdi Salem (1) , Sabine Le Roux (1) , Gilles Dour (1) , Farhad Rezai-Aria (1)

1 CROMeP - Centre de Recherche Outillages, Matériaux et Procédés

Effects of atmosphere and specimen geometry on thermal fatigue (TF) crack initiation and propagation in a low Si content hot work tool steel X38CrMoV5-47HRC were investigated. The TF specimen’s geometry enhances the uni-axial TF loading conditions. A high frequency induction heating (3 to 4 MHz) is used. A new TF rig, working under air and/or inert atmosphere with reduced PO2 has been set up. The reduction of PO2 results in localized oxidation sites. Whatever geometry and atmosphere conditions, TF cracks initiate exclusively in the oxide layers. Damage mechanisms are environment dependant. Under laboratory air, parallel macroscopic cracks initiate perpendicular to the hoop stress. Under argon and nitrogen, SEM surface observations show that initiated cracks coalesce by zigzagging along crystallographic paths between non-oxidized zones. In-depth crack propagation mechanism is mainly trans-granular. TF crack initiation life under air and in presence of Fe-Al intermetalllics is decreased in comparison to inert atmosphere.

Mots clés: Oxidation; Intermetallic; Tool steel; Isothermal fatigue; Thermal fatigue; Environmental effect; Intermetallics; Crack initiation; Crack propagation

Domaines: Sciences de l'ingénieur [physics]

Pascal Lamesle, Mehdi Salem, Sabine Le Roux, Gilles Dour, Farhad Rezai-Aria. Oxidation and Corrosion Effects on Thermal Fatigue Behaviour of Hot Work Tool Steel X38CrMoV5 (AISI H11). 7th International symposium on high-temperature corrosion and protection of materials, May 2008, Les Embiez, France. pp.789 - 796, ⟨10.4028/www.scientific.net/MSF.595-598.789⟩. ⟨hal-01685068⟩