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GB 9439 HT200 Grey Iron Castings Hardness, applications, chemical analysis and mechanical properties.
Characteristics of GB 9439 HT200 Gray Cast Iron:
High strength cast iron, pearlitic base, good strength, abrasion resistant, heat resistance and vibration reduction. The casting performance is good, and manual aging treatment is needed.
Applications of GB 9439 HT200 Gray Cast Iron:
1. Important castings in general machinery manufacturing, such as cylinders, gears, frames, beds and surfaces of metal cutting machines; Etc.
2. Cylinder blocks, cylinder heads, pistons, brake wheels, coupling discs and piston rings for gasoline and diesel engines of automobiles and tractors.
3. It has the joint construction of measuring planes, such as: marking plates, v-shaped irons, flat rulers, horizontal instrument frames, etc.
4. Hydraulic cylinders, pump bodies, valve bodies under medium pressure of 7.85mpa and pump shells and containers requiring certain corrosion resistance, such as pump bodies, pump covers, impellers, etc. of submersible sewage pumps.
5. Circumferential velocity > 12 ~ 20 m/s pulley and other listed items conform to the conditions of the parts.
6. Parts to be surface-hardened.
The example of Chemical analysis of GB 9439 HT200 Gray Cast Iron (mass fraction)(%)
Grade |
Thickness
/mm |
C |
Si |
Mn |
P
≤ |
S
≤ |
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 |
As for normal grey iron, the chemical composition is not important comparatively. The iron foundries could adjust the compositions according to their experience as long as they could meet the physical and mechanical requirements.
Mechanical properties of separately cast samples (30 mm diameter) of GB 9439 HT200 Gray Cast Iron:
Mechanical properties |
Material No. |
HT-200 |
Tensile strength Rm/Mpa |
200-300 |
Proof stress Rp0.1/MPa |
130-195 |
Elongation at fracture A/% |
0.3-0.8 |
Compression strength δdb /MPa |
720 |
Compression yield point δd0.1/MPa |
260 |
Bending strength δdB/MPa |
290 |
Shear strength δaB/MPa |
230 |
Torsional strength TtB/MPa |
230 |
Modulus of Elasticity E/(k MPa) |
88-113 |
Poisson ratio μ |
0.26 |
Bending fatigue strength δbW/MPa |
90 |
Fatigue limit under reversed tension-compression stresses δzdW/MPa |
50 |
Fracture toughness KIC/MPa3/4 |
400 |
GB 9439 HT200 Grey Iron Castings Hardness:
Grey iron grade |
Hardness grade |
Hardness Range HBS |
Metallography |
HT200 |
H195 |
170~220 |
Pearlite |
Alternative names:
Gray Cast Iron HT200 (GB 9439), GG20 (DIN 1691), EN-GJL-200 (EN 1561), GRADE 200 (ISO 185), CLASS 30 (ASTM A48), FC200 (JIS G5501), G20 (UNI 5007), FGL200 (NF A32-101), 180 (BS 1452), 200 (BS 1452), 220 (BS 1452), FG20 (UNF), FGG20 (NBN 830-01), T200 (AS 1830), T220 (AS 1830), O120 (SS 14 01), SJG200 (NS11 100) |
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