Mechanical properties of gray cast iron

The cooling rate during solidification and during the following phase transformations has a significant influence on the material’s strength as well as on its hardness. The values, given in the table below, refer to separately cast samples with a diameter of 30mm.

 

Mechanical properties of separately cast samples (30 mm diameter)

Mechanical properties

Material No.

HT-150

HT-200

HT-250

HT-300

HT-350

Microstructure

ferr./pearl

pearlitic

Tensile strength

Rm/Mpa

150-250

200-300

250-350

300-400

350-450

Proof stress

Rp0.1/MPa

98-165

130-195

165-228

195-260

228-285

Elongation at fracture A/%

0.3-0.8

0.3-0.8

0.3-0.8

0.3-0.8

0.3-0.8

Compression strength

δdb /MPa

600

720

840

960

1080

Compression yield point

δd0.1/MPa

195

260

325

390

455

Bending strength

δdB/MPa

250

290

340

390

490

Shear strength

δaB/MPa

170

230

290

345

400

Torsional strength

TtB/MPa

170

230

290

345

400

Modulus of Elasticity

E/(k MPa)

78-103

88-113

103-118

108-137

123-143

Poisson ratio μ

0.26

0.26

0.26

0.26

0.26

Bending fatigue strength

δbW/MPa

70

90

120

140

145

Fatigue limit under reversed tension-compression stresses

δzdW/MPa

40

50

60

75

85

Fracture toughness

KIC/MPa3/4

320

400

480

560

650