Grey Cast Iron Sand Casting Part

19 Mar.,2024

 

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.