MORA FONDERIE - Cast iron castings


Fonderie Mora GavardoProductionLarge CastingsCast IronQualityEcology & Environment

Gray irons

Their name comes from the gray look of the fracture. They have structures with a ferrite-perlitic matrix, in which irregular graphitic flakes that break up the continuity of the matrix are scattered. The mechanical properties of gray irons depend on the chemical composition of the alloy as well as on the average thickness of the castings.

Name

Mechanical properties

Casting’s average thickness in mm

3.5-7.5

7.5-15.0

15-30

30-50

G15

Tensile strength
(N/mm2)

210

150

130

-

Hardness (HB)

225

185

165

-

G20

Tensile strength
(N/mm2)

260

200

150

120

Hardness (HB)

235

205

175

155

G25

Tensile strength
(N/mm2)

310

250

210

160

Hardness (HB)

250

220

195

180

G30

Tensile strength
(N/mm2)

-

300

270

210

Hardness (HB)

-

235

215

205

G35

Tensile strength
(N/mm2)

-

350

320

270

Hardness (HB)

-

255

235

220



Ductile graphitic cast iron

It represents the completion of the studies carried out to find casting and treatment methods which could modify the graphite, turning the flake form into a nodular or a spheroid one, not to stop the continuity of the cast iron matrix, and thus getting rid of the first cause of the cast iron shortness. Another feature of the ductile cast iron is its good machinability, which is higher than for the steel and the common cast iron at the same hardness level one. The cast ability of this cast iron is definitely higher than that of the malleable iron and that of the steel, also allowing very complicated castings. Its atmospheric corrosion resistance is 5 times higher than the carbon steel one. Its oxidation resistance is much better than the flake graphitic iron one.

The application fields of this type of cast iron are:

Ductile cast iron

Classic applications

EN-GJS-400

Seal castings, compressor bodies, valves, cylinders, pump bodies, connecting rods,
high temperature applications with the maximum toughness, applications needing
high heat resistance…

EN-GJS-500

Applications in which a perlitic structure and a high tensile strength is requested…

EN-GJS-600

Gears, cams, bearings, pistons, crankshaft, pulleys…

The nodular cast irons mechanical features are:

Name

Mechanical features

Casting’s average thickness in mm

S<30

30<60<td

60<200<td

EN-GJS-350

Tensile strength
(N/mm2)

350

330

320

Hardness (HB)

<160

EN-GJS-400

Tensile strength
(N/mm2)

400

390

370

Hardness (HB)

140-200

EN-GJS-450

Tensile strength
(N/mm2)

450

430

400

Hardness (HB)

160-210

EN-GJS-500

Tensile strength
(N/mm2)

500

450

420

Hardness (HB)

170-230

EN-GJS-600

Tensile strength
(N/mm2)

600

600

550

Hardness (HB)

190-250

EN-GJS-700

Tensile strength
(N/mm2)

700

700

660

Hardness (HB)

240-310