What is Ductile Iron?

Ductile iron is also known as spheroidal graphite iron, ductile cast iron. The inner structure occurs as spheroids, so it is sometimes referred to as spheroidal graphite. It is a durable, fatigue-resistant metal. The ductile iron was invented in 1943, First patented in 1948. Ductile iron and cast iron have contrasting physical properties caused by differences in their microstructures. The carbon contained in ductile iron is held in the form of nodules. This unique microstructure causes ductile iron to withstand bending and shock loading better than cast iron.

What is Ductile Iron made from?

Ductile iron is mainly made from pig iron.

Pig iron refers to the crude iron that’s produced by smelting ore in a blast furnace. It is about 90% iron with high carbon content. Its chemical properties are very stable. Using a blast furnace, the pig iron is melted down and has carbon forced into the material beyond its normal capacity. Silicon, sulfur, and manganese help the excess carbon from the spherical graphite nodules as the metal cools in its cast. This process creates a durable, wear-resistant metal.

Ductile Iron Advantages

The ductile iron provides advantages for designers:

  • Easily to be cast and machine.
  • Excellent strength to weight ratio.
  • Lower cost than steel.
  • Great castability and machinability.

Ductile iron provides a designer with an exceptional combination of toughness, low-cost manufacturing and reliability.

Ductile Iron Properties

There are several matrices found within ductile iron. The most common graphite microstructure is below. The unique microstructure of each metal can cause its physical properties

  • Ferrite: a pure, ductile, flexible iron with little strength. This matrix has poor wear resistance, but high impact resistance and good machinability.
  • Pearlite: a mechanical mixture of ferrite and iron carbide (Fe3C). It is hard, with moderate ductility. It has high strength, good wear resistance, moderate impact resistance, and good machinability.
  • Pearlite/Ferrite: a structure consisting of a mixture of pearlite and ferrite. The most common matrix for commercial grades of ductile iron.

World Ductile Iron Grades List

1ChinaQT400-18QT450-10QT500-7QT600-3QT700-2QT800-2QT900-2
2JapanFCD400FCD450FCD500FCD600FCD700FCD800—
3USA60-40-1865-45-1270-50-0580-60-03100-70-03120-90-02—
4RussiaB Ч 40B Ч 45B Ч 50B Ч 60B Ч 70B Ч 80B Ч 100
5GermanyGGG40—GGG50GGG60GGG70GGG80—
6ItalyGS370-17GS400-12GS500-7GS600-2GS700-2GS800-2—
7FranceFGS370-17FGS400-12FGS500-7FGS600-2FGS700-2FGS800-2—
8England400/17420/12500/7600/7700/2800/2900/2
9PolandZS3817ZS4012ZS5002ZS6002ZS7002ZS8002ZS9002
10IndiaSG370/17SG400/12SG500/7SG600/3SG700/2SG800/2—
11Romania————FGN70-3——
12SpainFGE38-17FGE42-12FGE50-7FGE60-2FGE70-2FGE80-2—
13BelgiumFNG38-17FNG42-12FNG50-7FNG60-2FNG70-2FNG80-2—
14Australia400-12400-12500-7600-3700-2800-2—
15Sweden0717-02—0727-020732-030737-010864-03—
16HungaryGǒV38GǒV40GǒV50GǒV60GǒV70——
17Bulgaria380-17400-12450-5, 500-2600-2700-2800-2900-2
18ISO400-18450-10500-7600-3700-2800-2900-2
19COPANT—FMNP45007FMNP55005FMNP65003FMNP70002——
20China TaiwanGRP400—GRP500GRP600GRP700GRP800—
21HollandGN38GN42GN50GN60GN70——
22LuxembourgFNG38-17FNG42-12FNG50-7FNG60-2FNG70-2FNG80-2—
23AustriaSG38SG42SG50SG60SG70——

What is Ductile Iron Usage?

Because of ductile iron strength and malleability, it is used widely in many different industries. Including

  • Pipes and pipe fittings.
  • Automotive industry engine connecting rods, cylinders, crankshafts, truck axles, and gears
  • Machine Parts, machine frames, and cable drums.

When you are looking for a strong, stable material that can withstand tough conditions over a long period of time, ductile iron will be a great choice

Common Ductile Iron Grades used in JC Casting

While there are many different ductile iron specifications, JC CASTING foundries routinely offer 3 common grades;

PHYSICAL AND MECHANICAL PROPERTIES

ASTM A536, GRADE 60-40-18

ASTM A536, GRADE 65-45-12

ASTM A536, GRADE 80-55-06

Tensile Strength, min, psi

60,000

65,000

80,000

Tensile Strength, min, MPa

414

448

552

Yield Strength, min, psi

40,000

45,000

55,000

Yield Strength, min, MPa

276

310

379

Elongation in 2 in. or 50 mm, min %

18

12

6

Density lb/in3

0.256

0.256

0.256

Density g/cm3

7.1

7.1

7.1

Melting Temperature (Degrees F)

2,100 – 2,190

2,100 – 2,190

2,100 – 2,190

Melting Temperature (Degrees C)

1,150 – 1,200

1,150 – 1,200

1,150 – 1,200

Compressive Strength Ksi

429

429

429

Compressive Strength MPa

2960

2960

2960

UNS

F32800

F33100

F33800

Custom Ductile Iron Casting Services

JC Casting Foundry is a Ductile Iron Casting manufacturer and supplier in China. Get a quote details on our service to meet your projects. Email us: info@jccasting.comF

FAQ

Iten Cast iron Ductile iron
Durability Cast iron is a strong material that can handle higher pressures. Ductile iron also has impressive structural integrity. It can handle high pressures and temperatures without flinching.  
Price Lower more expensive 
 Cast iron is brittle and it breaks when bent.Ductile iron can be bent without breaking.
 Cast iron is not flexibleDuctile iron is flexible,
ApplicationsCast iron is mainly seen in the construction industry.Ductile iron is mainly used in the automobile industry such as trucks, tractors and oil pumps.
difference between Ductile Iron and Cast Iron Table
Itemductile iron Grey iron
Physical property


 higher tensile strength and yield strength, elongation rate.
more durable, reliable and tough.		has good abrasive resistance and cast ability.

lower tensile strength and elongation.
Production process

more complex and difficultSimple process
Microstructure
has many graphite ballshas many graphite flakes
ApplicationCasting parts for machinery, tractors, trucks, automotiveStove parts, boiler parts, machinery bases
lower prices
Casting ProdcutsDuctile iron castings are the products. Ductile iron is just a material.Grey iron castings are the products. Grey iron is just a material.