As cast high silicon ductile irons with optimised mechanical properties and remarkable fatigue properties

Urko de La Torre (1) , Aitor Loizaga (1) , Jacques Lacaze (2) , Jon Sertucha (1)

1 Azterlan - Centro de Investigación Metalúrgica
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

The present work shows a comparative study regarding the mechanical properties of 25 as cast ferritic ductile iron alloys, nine of them with silicon contents higher than 3·00% and carbon contents lower than 3·60%. In a first step, different carbon equivalent values have been used in order to analyse the effect of this parameter on the mechanical properties. After this comparative analysis, the composition ranges C = 3·30–3·40 wt-% and Si = 3·75–3·80 wt-% have been selected as the most proper ones to optimise the tensile and impact properties among the high silicon ductile iron alloys. Finally, a second study was carried out to compare the tensile and fatigue properties of the optimised high silicon alloy with the corresponding ones obtained from an EN GJS 400-18-LT grade alloy with low silicon content. Although the room temperature impact values obtained from the high silicon ductile iron are lower than 6 J cm−2, the measured fatigue limit of this alloy (358 MPa) is clearly higher than the one obtained from the low silicon cast iron (170 MPa). A discussion about the benefits and advantages of the high silicon alloy is included.

Mots clés: Ductile irons; High silicon; Mechanical properties; Fatigue properties

Domaines: Matériaux; Matériaux

Urko de La Torre, Aitor Loizaga, Jacques Lacaze, Jon Sertucha. As cast high silicon ductile irons with optimised mechanical properties and remarkable fatigue properties. Materials Science and Technology, 2014, vol. 30 (n° 12), pp. 1425-1431. ⟨10.1179/1743284713Y.0000000483⟩. ⟨hal-01179619⟩