Grey Cast Iron Property and Chemical Composition
Grey Cast Iron (Gray iron castings) is so called because of the colour of the fracture face. It contains 1.5-4.3% carbon and 0.3-5% silicon plus manganese, sulfur and phosphorus. It is brittle with low tensile strength, but is easy to cast.
The all data in this documents is referred to Chinese standard of GB/T 9439-1988. Qingdao Casting Quality Ind write all materials from handbook.
grey cast iron composition.pdf
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 Grade |
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
|
Gray Iron Grade |
Hardness Grade |
Hardness Range HB |
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/οC |
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 |
