Effect of aluminizing and oxidation on the thermal fatigue damage of hot work tool steels for high pressure die casting applications

Mehdi Salem (1) , Sabine Le Roux (1) , Gilles Dour (2) , Pascal Lamesle (3) , Karim Choquet (1) , Farhad Rezai-Aria (1)

1 ICA - Institut Clément Ader
2 WorleyParsons
3 IRT M2P - Institut de recherche technologique Matériaux Métallurgie et Procédés

The interaction between thermal fatigue and aluminizing and/or oxidation is investigated using an experimental approach based on decoupling of mechanisms. Virgin and pre-aluminized steel specimens are tested in air and nitrogen between 100 and 650 °C. Homogeneous uniaxial micro-crack network forms on the oxidised or pre-aluminized surface in air, with a better resistance to micro-cracking for the intermetallic coating. The propagation of the micro-cracks is delayed in nitrogen, whilst no evidence of micro-cracking is observed on the virgin specimen. The premature cracking of the steel depends on the formation of the superficial micro-crack network, and the crack propagation is assisted by oxidation.

Mots clés: Corrosion; Intermetallics; Cracks; Tool steel; Thermal fatigue

Domaines: Matériaux; Mécanique des matériaux [physics.class-ph]

Mehdi Salem, Sabine Le Roux, Gilles Dour, Pascal Lamesle, Karim Choquet, et al.. Effect of aluminizing and oxidation on the thermal fatigue damage of hot work tool steels for high pressure die casting applications. International Journal of Fatigue, 2019, 119, pp.126-138. ⟨10.1016/j.ijfatigue.2018.09.018⟩. ⟨hal-01898697⟩