GB 9439 HT350 is a gray cast iron with high strength and high wear resistance.
Its strength and wear resistance are better than other grades. However, it has a large tendency of white opening and poor casting performance, so it needs manual aging treatment after casting. Suitable for high stress (σω<49MPa), unit pressure between friction surfaces ≥ 1.96Mpa, and required to maintain a high degree of air tightness parts.
The common application for GB 9439 HT350 Gray Cast Iron:
Under high load, wear and high air tightness important casting, such as heavy machine tools, shears, presses, automatic lathe bed, frame, high-pressure hydraulic parts, piston rings, force larger gear, cams, bushings, large engine crankshaft, cylinder block, cylinder liner, cylinder head, etc.
The example of Chemical analysis of GB 9439 HT350 Grey Cast Iron(mass fraction)(%)
Material No. |
Wall thickness
/mm |
C |
Si |
Mn |
P
≤ |
S
≤ |
HT-350 |
<15
15~30
30~50
>50 |
2.9~3.2
2.8~3.1
2.8~3.1
2.7~3.0 |
1.4~1.7
1.3~1.6
1.2~1.5
1.1~1.4 |
0.9~1.2
1.0~1.3
1.0~1.3
1.1~1.4 |
0.15 |
0.12 |
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 HT350 Gray Cast Iron
Mechanical properties |
Material No. |
HT-350 |
Tensile strength Rm/Mpa |
350-450 |
Proof stress Rp0.1/MPa |
228-285 |
Elongation at fracture A/% |
0.3-0.8 |
Compression strength δdb /MPa |
1080 |
Compression yield point δd0.1/MPa |
455 |
Bending strength δdB/MPa |
490 |
Shear strength δaB/MPa |
400 |
Torsional strength TtB/MPa |
400 |
Modulus of Elasticity E/(k MPa) |
123-143 |
Poisson ratio μ |
0.26 |
Bending fatigue strength δbW/MPa |
145 |
Fatigue limit under reversed tension-compression stresses δzdW/MPa |
85 |
Fracture toughness KIC/MPa3/4 |
650 |
GB 9439 HT350 Grey Iron Castings Hardness:
Grey iron grade |
Hardness grade |
Hardness RangeHBS |
Metallography |
HT350 |
H255 |
230~280 |
Pearlite(Inoculated Cast Iron) |
China GB 9439 HT350 Equivalent Grades:
Country |
Standard |
Material Grade |
|
ISO |
ISO 185 |
GRADE350 |
|
USA |
ASTM A48 |
CLASS 50 |
|
Germany / Austria |
DIN 1691 |
GG35 |
|
European |
EN 1561 |
EN-GJL-350 |
|
Japan |
JIS G5501 |
FC350 |
|
Italy |
UNI 5007 |
G35 |
|
France |
NF A32-101 |
FGL350 |
|
UK |
BS 1452 |
350 |
|
Spain |
UNF |
FG35 |
|
Belgium |
NBN 830-01 |
FGG35 |
|
Australia |
AS 1830 |
T350 |
|
Sweden |
SS 14 01 |
O135 |
|
Norway |
NS11 100 |
SJG350 |
|
