Grey cast iron products by sand mould casting process and CNC machining.
Grey cast iron is named after the gray color of the fracture it forms. The gray cast iron is used for housings where the stiffness of the component is more important than its tensile strength, such as internal combustion engine cylinder blocks, pump housings, valve bodies, electrical boxes, counter weights and decorative castings. Grey cast iron's high thermal conductivity and specific head capacity are often exploited to make cast iron cookware and disc brake rotors.
A typical chemical composition to obtain a graphitic microstructure is 2.5 to 4.0% carbon and 1 to 3% silicon by weight. Graphite may occupy 6 to 10% of the volume of grey iron. Silicon is important to making grey iron as opposed to white cast iron, because silicon is a graphite stabilizing element in cast iron, which means it helps the alloy produce graphite instead of iron carbides; at 3% silicon almost no carbon is held in chemical combination with the iron.
The graphite takes on the shape of a three-dimensional flake. In two dimensions, as a polished surface will appear under a microscope, the graphite flakes appear as fine lines. The tips of the flakes act as preexisting notches; therefore, it is brittle. The presence of graphite flakes makes the Grey Iron easily machinable as they tend to crack easily across the graphite flakes. Grey iron also has very good damping capacity and hence it is mostly used as the base for machine tool mountings.
Gray Cast Iron Mechanical Properties
Item according to DIN EN 1561
Measure
Unit
EN-GJL-150
EN-GJL-200
EN-GJL-250
EN-GJL-300
EN-GJL-350
EN-JL 1020
EN-JL 1030
EN-JL 1040
EN-JL 1050
EN-JL 1060
Tensile Strength
Rm
MPA
150-250
200-300
250-350
300-400
350-450
0.1% Yield Strength
Rp0,1
MPA
98-165
130-195
165-228
195-260
228-285
Elongation Strength
A
%
0,3 – 0,8
0,3 – 0,8
0,3 – 0,8
0,3 – 0,8
0,3 – 0,8
Compressive Strength
σdB
MPa
600
720
840
960
1080
0,1% Compressive Strength
σd0,1
MPa
195
260
325
390
455
Flexural Strength
σbB
MPa
250
290
340
390
490
Schuifspanning
σaB
MPa
170
230
290
345
400
Shear Stress
TtB
MPa
170
230
290
345
400
Modules of elasticity
E
GPa
78 – 103
88 – 113
103 – 118
108 – 137
123 – 143
Poisson number
v
–
0,26
0,26
0,26
0,26
0,26
Brinell hardness
HB
160 – 190
180 – 220
190 – 230
200 – 240
210 – 250
Ductility
σbW
MPa
70
90
120
140
145
Tension and pressure change
σzdW
MPa
40
50
60
75
85
Breaking Strength
Klc
N/mm3/2
320
400
480
560
650
Density
g/cm3
7,10
7,15
7,20
7,25
7,30
Sand casting uses green sand (moist sand) or dry sand to form the molding systems. The green sand casting is the oldes casting process used in history. When making the mold, the patterns made of wood or metal should be produced in order to form the hollow cavity. The molten metal then pour into the cavity to form the castings after cooling and solidification. Sand casting is less expensive than other casting processes both for mold development and unit casting part. The sand casting, always mean the green sand casting (if no special description). However, nowadays, the other casting processes are also use the sand to make the mold. They have their own names, such as shell mold casting, furan resin coated sand casting (no bake type), lost foam casting and vacuum casting.
Sand Casting Capabilities at RMC Foundry
Description
Molding by Manual
Molding by Automatic Machines
Max size of Castings
1,500 mm × 1000 mm × 500 mm
1,000 mm × 800 mm × 500 mm
Casting Weight Range
0.5 kg - 1,000 kg
0.5 kg - 500 kg
Annual Capacity
5,000 tons - 6,000 tons
8,000 tons - 10,000 tons
Casting Tolerance
On Request or Standard (ISO8062-2013 or GB/T 6414-1999)
Molding Materials
Green Sand, Resin Coated Sand
Casting Metal & Alloys
Gray Iron, Ductile Iron, Cast Steel, Stainless Steel, Al Alloys, Brass, Bronze...etc.
The Advantages of Sand Casting:
✔ Lower Cost due to its cheap and recyclable mold materials and simple production equipment.
✔ Wide range of unit weight from 0.10 kg to 500 kgs or even bigger.
✔ Various Structure from simple type to complex type.
✔ Suitable for production requirements of various quantity.
Tolerance That Sand Castings Achieve:
The casting tolerances are divided into Dimensional Casting Tolerances (DCT) and Geometrical Casting Tolerances (GCT). Our foundry would like to talk with you if you have special request on the required tolerances. Here in the following are the general tolerances grade we could reach by our green sand casting, shell mould casting and no-bake furan resin sand casting:
✔ DCT Grade by Green Sand Casting: CTG10 ~ CTG13
✔ DCT Grade by Shell Mold Casting or Furan Resin Sand Casting: CTG8 ~ CTG12
✔ GCT Grade by Green Sand Casting: CTG6 ~ CTG8
✔ GCT Grade by Shell Mold Casting or Furan Resin Sand Casting: CTG4 ~ CTG7
Metal & Alloys Grade for Sand Casting Processes
Metal & Alloys
Popular Grade
Gray Cast Iron
GG10~GG40; GJL-100 ~ GJL-350;
Ductile (Nodualar) Cast Iron
GGG40 ~ GGG80; GJS-400-18, GJS-40-15, GJS-450-10, GJS-500-7, GJS-600-3, GJS-700-2, GJS-800-2
Austempered Ductile Iron (ADI)
EN-GJS-800-8, EN-GJS-1000-5, EN-GJS-1200-2
Carbon Steel
C20, C25, C30, C45
Alloy Steel
20Mn, 45Mn, ZG20Cr, 40Cr, 20Mn5, 16CrMo4, 42CrMo,
40CrV, 20CrNiMo, GCr15, 9Mn2V
Stainless Steel
Ferritic Stainless Steel, Martensitic Stainless Steel, Austenitic Stainless Steel, Precipitation Hardening Stainless Steel, Duplex Stainless Steel
Aluminium Alloys
ASTM A356, ASTM A413, ASTM A360
Brass / Copper-based Alloys
C21000, C23000, C27000, C34500, C37710, C86500, C87600, C87400, C87800, C52100, C51100
Standard: ASTM, SAE, AISI, GOST, DIN, EN, ISO, and GB
If you have any questions on sand casting grey cast iron, Cast Iron and Cast Steel. We will give the professional answers to your questions.