Effect of cast iron microstructure on adherence of an epoxy protection

Alexandre Freulon (1) , Anh Truc Trinh (2) , Jacques Lacaze (1) , Benoît Malard (1) , Ke Oanh Vu (2)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 Institute for Tropical Technology

To study the influence of the microstructure of cast iron on the adhesion of an epoxy coating, ferritic, pearlitic and austempered samples were prepared in as-received, polished and oxidized states. A pull-off test (dry adhesion) was performed before immersing in water while the cross-cut test was made after 24 days of exposition in distilled water (wet adhesion). X-rays were combined with optical microscopy (LOM) and scanning electron microscopy (SEM) for surface analysis. The adhesion of the epoxy coating on the cast iron surface firstly depends on the roughness of the surface; polished samples showed high adherence by comparison with as-received samples. On the oxidized samples, the surface oxide significantly improves the adhesion of the coating in both dry and wet states for all three sample microstructure. The presence of carbide in the structure was observed to decrease adherence.

Mots clés: Spheroidal graphite cast iron; pearlitic; ferritic; ADI; epoxy coating; adhesion

Domaines: Matériaux

Alexandre Freulon, Anh Truc Trinh, Jacques Lacaze, Benoît Malard, Ke Oanh Vu. Effect of cast iron microstructure on adherence of an epoxy protection. International Journal of Cast Metals Research, The, In press. ⟨hal-03054007v1⟩