Ductile IRON

Ductile casting, alloys of steel, carbon and silicon was invented in 1943. Contrary to gray iron, wherein the graphite appears in the form of graphite flakes, in ductile iron they appear in the form of nodules. This helps eliminate the risk of cracks, so it is a lot more resistant than gray iron. In addition to keeping the traditional properties of gray iron, that’s to say, resistance to shrinkage, easy to cast, resistance to scoring and galling, machining qualities and resistance to fatigue, ductile casting qualities include: high tensile strength, shock resistance, high fluidity and extendable qualities. Its popularity comes from the fact that its properties are competitive with several types of steel, with the added advantage of having much lower fabrication costs.

Microstructure of ductile casting

Grades of ductile iron available from fonderie laroche
According to astm-a-536 standards
Type Tensile strength (PSI) Yield strength Elongation percent Hardness (Brinell) Typical microstructure
65-45-12 65 000 45 000 12 149 – 229 Ferritic
80-55-06 80 000 55 000 6 179 – 255 Ferritic & Pearlite
100-70-03 100 000 70 000 3 229 - 302 All Pearlite

Equivalence according to foreign standards
Type DIN 1693 DIN EN 1563 ISO 1083
65-45-12 - - -
80-55-06 GGG-50 EN-GJS-500-7U 500-7
100-70-03 GGG-70 EN-GJS-700-2U 700-2