Grey Cast Iron (Gray iron) is so called because
of the color of the fracture face. It contains 1.5-4.3% carbon
and 0.3-5% silicon plus manganese, sulphur and phosphorus. It is
brittle with low tensile strength, but is easy to cast.
The all data in this document is referred to Chinese standard of
GB/T 9439-1988.
Single Casting Specimen Tensile Strength Property
Gray iron
grade |
Single
specimen
Tensile Strength
σb≥/Mpa
|
Gray iron
castings |
Wall
thickness/mm |
Tensile
strength
σb≥/Mpa
|
HT100 |
100 |
>2.5~10
>10~20
>20~30
>30~40 |
130
100
90
80 |
HT150 |
150 |
>2.5~10
>10~20
>20~30
>30~40 |
175
145
130
120 |
HT200 |
200 |
>2.5~10
>10~20
>20~30
>30~40 |
220
195
170
160 |
HT250 |
250 |
>4.0~10
>10~20
>20~30
>30~50 |
270
240
220
200 |
HT300 |
300 |
>10~20
>20~30
>30~50 |
290
250
230 |
HT350 |
350 |
>10~20
>20~30
>30~50 |
340
290
260 |
Castings Attached Specimen Tensile Strength
Property
Gray iron
grad |
Wall
thickness
/mm |
Tensile
strength σb≥/Mpa
|
Tensile
strength (reference)
σb≥/Mpa |
Attached
test coupon |
Attached
test block |
φ30mm |
φ50mm |
R15mm |
R25mm |
HT150 |
>20~40
>40~80
>80~150
>150~300 |
130
115
-
- |
-
(115)
105
100 |
120
110
-
- |
-
-
100
90 |
120
105
90
80 |
HT200 |
>20~40
>40~80
>80~150
>150~300 |
180
160
-
- |
-
(155)
145
135 |
170
150
-
- |
-
-
140
130 |
165
145
130
120 |
HT250 |
>20~40
>40~80
>80~150
>150~300 |
220
200
-
- |
-
(190)
180
165 |
(210)
190
-
- |
-
-
170
160 |
205
180
165
150 |
HT300 |
>20~40
>40~80
>80~150
>150~300 |
260
235
-
- |
-
(230)
210
195 |
(250)
225
-
- |
-
-
200
185 |
245
215
195
180 |
HT350 |
>20~40
>40~80
>80~150
>150~300 |
300
270
-
- |
-
(265)
240
215 |
(290)
260
-
- |
-
-
230
210 |
285
255
225
205 |
Grey Iron Castings’ other mechanical property
Grade
|
Compressive
Strength
σbc/MPa |
Shearing
Strength
τb/Mpa |
Impact
Testing
αKV/(J/cm2) |
Safe Range
of
stress
σ-1/MPa |
Modulus of
Elasticity
Ε/GPa |
HT150 |
500~700 |
150~250 |
- |
60~90 |
70~90 |
HT200 |
600~800 |
200~300 |
2~5 |
80~90 |
80~110 |
HT250 |
800~1000 |
250~350 |
4~8 |
100~140 |
100~130 |
HT300 |
1000~1200 |
300~450 |
7~10 |
120~160 |
120~140 |
HT350 |
1100~1300 |
350~500 |
9~11 |
140~180 |
130~160 |
Grey Iron Castings Hardness
Grey iron
grade |
Hardness
grade |
Hardness
Range
HBS |
Metallography
|
HT100 |
H145 |
≤170 |
Ferrite |
HT150 |
H175 |
150~200 |
Ferrite +
Pearlite |
HT200 |
H195 |
170~220 |
Pearlite |
HT250 |
H215 |
190~240 |
Pearlite |
HT300 |
H235 |
210~260 |
Pearlite(Inoculated Cast
Iron) |
HT350 |
H255 |
230~280 |
Pearlite(Inoculated Cast
Iron) |
Gray Iron Casting heat treatment
Casting Unit
Weight
kg |
Starting
Temperature
/οC |
Heating
Speed
/(οC/h) |
Preservation
temperature |
Heat
Preservation
Time
/h |
Cooling
Speed
/(οC/h) |
Final
Temperature
/οC |
Cast iron |
Low alloy
cast iron |
Simple
castings |
<200 |
≤200 |
≤100 |
500~550 |
550~570 |
4~6 |
30 |
200 |
200~2500 |
≤200 |
≤80 |
500~550 |
550~570 |
6~8 |
30 |
200 |
>2500 |
≤200 |
≤60 |
500~550 |
550~570 |
8 |
30 |
200 |
Precision
Castings |
<200 |
≤200 |
≤100 |
500~550 |
550~570 |
4~6 |
20 |
200 |
200~2500 |
≤200 |
≤80 |
500~550 |
550~570 |
6~8 |
20 |
200 |
Gray Iron Casting, no any standard mentioned
the chemistry composition, so we only suggest the following
chemistry based on actual production.
Grade |
Wall
Thickness
/mm |
C |
Si |
Mn |
P ≤ |
S ≤ |
HT100 |
- |
3.4~3.9 |
2.1~2.6 |
0.5~0.8 |
0.3 |
0.15 |
HT150 |
<30
30~50
>50 |
3.3~3.5
3.2~3.5
3.2~3.5 |
2.0~2.4
1.9~2.3
1.8~2.2 |
0.5~0.8
0.5~0.8
0.6~0.9 |
0.2
0.2
0.2 |
0.12
0.12
0.12 |
HT200 |
<30
30~50
>50 |
3.2~3.5
3.1~3.4
3.0~3.3 |
1.6~2.0
1.5~1.8
1.4~1.6 |
1.7~0.9
0.8~1.0
0.8~1.0 |
0.15
0.15
0.15 |
0.12
0.12
0.12 |
HT250 |
<30
30~50
>50 |
3.0~3.3
2.9~3.2
2.8~3.1 |
1.4~1.7
1.3~1.6
1.2~1.5 |
0.8~1.0
0.9~1.1
1.0~1.2 |
0.15
0.15
0.15 |
0.12
0.12
0.12 |
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 |
Grey Cast Iron Compare
Index |
County |
Grey iron
grade |
1 |
China |
- |
HT350 |
HT300 |
HT250 |
HT200 |
HT150 |
HT100 |
2 |
Japanese |
- |
FC350 |
FC300 |
FC250 |
FC200 |
FC150 |
FC100 |
3 |
USA |
NO.60 |
NO.50 |
NO.45 |
NO.35/NO.40 |
NO.30 |
NO.25 |
NO.20 |
4 |
Russia |
CЧ40 |
CЧ35 |
CЧ30 |
CЧ34/ CЧ25 |
CЧ18/ CЧ20/
CЧ21 |
CЧ15 |
CЧ10 |
5 |
Germany |
GG40 |
GG35 |
GG30 |
GG25 |
GG20 |
GG15 |
GG10 |
6 |
Italy |
- |
G35 |
G30 |
G25 |
G20 |
G15 |
G10 |
7 |
France |
HGL400 |
FGL350 |
FGL300 |
FGL250 |
FGL200 |
FGL150 |
- |
8 |
England |
400 |
350 |
300 |
260 |
180/220 |
150 |
100 |
9 |
Poland |
Z140 |
Z135 |
Z130 |
Z125 |
Z120 |
Z115 |
- |
10 |
India |
FG400 |
FG350 |
FG300 |
FG260 |
FG200 |
FG150 |
- |
11 |
Romania |
FC400 |
FC350 |
FC300 |
FC250 |
FC200 |
FC150 |
- |
12 |
Spanish |
- |
FG35 |
FG30 |
FG25 |
FG20 |
FG15 |
- |
13 |
Belgium |
FGG40 |
FGG35 |
FGG30 |
FGG25 |
FGG20 |
FGG15 |
FGG10 |
14 |
Australia |
T400 |
T350 |
T300 |
T260 |
T220 |
T150 |
- |
15 |
Sweden |
O140 |
O135 |
O130 |
O125 |
O120 |
O115 |
O110 |
16 |
Hungary |
OV40 |
OV35 |
OV30 |
OV25 |
OV20 |
OV15 |
- |
17 |
Bulgaria |
- |
Vch35 |
Vch30 |
Vch25 |
Vch20 |
Vch15 |
- |
18 |
ISO |
- |
350 |
300 |
250 |
200 |
150 |
100 |
19 |
COPANT |
FG400 |
FG350 |
FG300 |
FG250 |
FG200 |
FG150 |
FG100 |
20 |
Taiwan
(China) |
- |
- |
FC300 |
FC250 |
FC200 |
FC150 |
FC100 |
21 |
Holland |
- |
GG35 |
GG30 |
GG25 |
GG20 |
GG15 |
- |
22 |
Luxemburg |
FGG40 |
FGG35 |
FGG30 |
FGG25 |
FGG20 |
FGG15 |
- |
23 |
Austria |
- |
GG35 |
GG30 |
GG25 |
GG20 |
GG15 |
|
24 |
Europa-Norm |
|
EN-GJL-350 |
EN-GJL-300 |
EN-GJL-250 |
EN-GJL-200 |
EN-GJL-150 |
|
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