GB 9439 HT300 Gray Cast Iron is suitable for manufacturing castings with high bending stress and high air tightness.
This material grade is good for heavy machine beds, gears, large engine crankshafts and cylinder bodies, high pressure cylinders, rolling mill blocks, etc.
The example of Chemical analysis of GB 9439 HT300 Grey Cast Iron(mass fraction)(%)
Grade |
Thickness
/mm |
C |
Si |
Mn |
P
≤ |
S
≤ |
HT300 |
<30
30~50
>50 |
2.9~3.2
2.9~3.2
2.8~3.1 |
1.4~1.7
1.2~1.5
1.1~1.4 |
0.8~1.0
0.9~1.1
1.0~1.2 |
0.15
0.15
0.15 |
0.10
0.10
0.10 |
Please notice, the chemical composition can not be taken as material quality inspection standard. In all standards, the chemical composition is just for reference. The grey iron foundries could adjust their composition according to their own production condition and experience, as long as they could guarantee to meet the mechanical properties, which is the only inspection standard.
Mechanical properties of separately cast samples (30 mm diameter) of GB 9439 HT300 Gray Cast Iron
Mechanical properties |
Material No. |
HT-300 |
Tensile strength Rm/Mpa |
300-400 |
Proof stress Rp0.1/MPa |
195-260 |
Elongation at fracture A/% |
0.3-0.8 |
Compression strength δdb /MPa |
960 |
Compression yield point δd0.1/MPa |
390 |
Bending strength δdB/MPa |
390 |
Shear strength δaB/MPa |
345 |
Torsional strength TtB/MPa |
345 |
Modulus of Elasticity E/(k MPa) |
108-137 |
Poisson ratio μ |
0.26 |
Bending fatigue strength δbW/MPa |
140 |
Fatigue limit under reversed tension-compression stresses δzdW/MPa |
75 |
Fracture toughness KIC/MPa3/4 |
560 |
GB 9439 HT300 Grey Iron Castings Hardness:
Grey iron grade |
Hardness grade |
Hardness Range HBS |
Metallography |
HT300 |
H235 |
210~260 |
Pearlite(Inoculated Cast Iron) |
China GB 9439 HT300 Equivalent Grades:
Country |
Standard |
Material Grade |
|
ISO |
ISO 185 |
GRADE300 |
|
USA |
ASTM A48 |
CLASS 40, CLASS 45 |
|
Germany / Austria |
DIN 1691 |
GG30 |
|
European |
EN 1561 |
EN-GJL-300 |
|
Japan |
JIS G5501 |
FC300 |
|
Italy |
UNI 5007 |
G30 |
|
France |
NF A32-101 |
FGL300 |
|
UK |
BS 1452 |
300 |
|
Spain |
UNF |
FG30 |
|
Belgium |
NBN 830-01 |
FGG30 |
|
Australia |
AS 1830 |
T300 |
|
Sweden |
SS 14 01 |
O130 |
|
Norway |
NS11 100 |
SJG300 |
|
