What is ductile iron made from – Manufacturing composition of Ductile Iron

What components is ductile iron made from

What components is ductile iron made from? What are the detailed proportions of its composition? What is the symbol for ductile iron? Which standards are the grades of ductile iron named after? Let's find out the details with HOA BINH GROUP in the article below.

*Note: Details on the composition ratios of common ductile iron grades are provided at the end of the article

See more:

>> What is the difference between ductile iron and gray iron?

>> What is the density of cast iron?

What is ductile iron?

Ductile Iron in English is "Ductile Iron".

"Ductile Iron is the type of cast iron with the most condensed graphite structure in the form of nodules (Spheroidal graphite due to modification with elements like Mg, Ce, and rare earth elements). Therefore, ductile iron has the highest strength among graphite cast irons."

Which is better: ductile iron or gray iron?

Ductile Iron is stronger and has better impact resistance than Gray Iron.

Microstructure of ductile iron and gray iron

Therefore, although ductile iron is more expensive than gray iron. Because *ductile iron is made from more expensive raw materials*. It is actually a more economical choice than gray iron. Because castings made of ductile iron are often lighter at the same size and design. So, overall, castings made from ductile iron have better quality, and the price difference is not significant, sometimes even cheaper.

What components is ductile iron made from?

Ductile iron is made from: C: 3 – 3.6%; Si: 2 – 3%; Mn: 0.5 – 1%; Ni < 2%; Mg: 0.04 – 0.08%; P £ 0.15%; S £ 0.03% and some other components.

Different compositions and casting techniques will produce ductile iron with different grades.

What are the grades of ductile iron?

Ductile iron grades depend on the evaluation standard.

• According to the Japanese JSC standard:

  FCD 450-10, FCD 500-7, FCD 600-3, FCD 700-2.

• According to standard 1659 – 75:

  GC45-5, GC40-10. The ductile iron symbol consists of 2 parts: the letters indicating the type of iron: GC, and the next two numbers indicating the tensile strength and relative elongation.

• According to US standards:

  • According to the SAE standard, there are the following iron grades: D4018, D4512, D5506, D7003 where the first two digits indicate values in ksi, and the latter two digits indicate values in %
  • According to the ASTM standard, we have the following iron grades: 60-40-18, 65-45-12, 80-55-06, 100-7–3, 120-90-2. The numbers sequentially indicate the minimum values of yield stress, tensile stress, and % elongation.

• Russian standard:

  CЧ10, CЧ15,.. . (Symbol CЧ) pronounced Che-che indicates cast iron. Iron grades with medium strength, σb = 150 – 200MPa, with a relatively coarse ferrite – pearlite lamellar matrix such as CЧ 20, CЧ25 are used for components subjected to light loads and less wear such as gearbox casings, machine bodies, flanges, sumps, and water pipes.

• According to Vietnamese standards:

  • According to the BS EN 124 standard, there are common iron grades such as: FCD 500-7. In which, the values are sequentially shown as the load-bearing force and tensile strength. The tensile strength of grade FCD 500-7 is >= 500 MPa and the corresponding elongation is 7%
  • According to the TCVN 5016-1987 standard, we have the characteristic iron grade: Grade GC45-5, where the 2 values shown are the mechanical tensile strength >=400 MPA and the elongation is 5%

Below, HOA BINH GROUP provides you with the *composition* of *ductile iron grades* according to the **ASTM** standard.

According to this standard, the *ductile iron grade is **[ASTM A536].***

What is ductile iron grade ASTM A536 80-55-06 made from?

Ductile Iron grade ASTM A536 80-55-06 is ductile iron with a microstructure primarily composed of pearlitic. Below are the typical technical specifications for GC Grade 80-55-06.

(HOA BINH ductile iron manhole covers and drain grates belong to this iron grade)

Ductile iron grade ASTM A536 80-55-06 is made from the following components in these ratios:

Physical and mechanical properties of ASTM A536 80-55-06

General properties of ductile iron made from the above components:

The impact properties of cast iron depend on the microstructure. If impact testing is required for the engineering design, consider using a fully ferritic ductile iron with higher % elongation. The ISO 1083 standard specifies Charpy values for low-temperature applications.

Advantages of ductile iron made from these components:

Ductile iron is easy to cast and machine. Ductile iron has great vibration damping properties and good corrosion resistance.

In addition, ductile iron made from the above components has high strength and large weight-to-strength ratio. And it can be manufactured at a much lower cost than steel. This is partly because the raw materials used to cast ductile iron are cheaper than those for steel.

Tip: When considering converting from fabrication to casting, ductile iron should be used for the reasons listed above (castability, machinability, close to steel strength, and good cost).

Applications of ductile iron:

Ductile iron is applied in the manufacturing of: brakes, gearboxes, frames, oil and gas components, pump parts, compressor parts, mining components, winch components, wind power, and other applications.

These ductile iron grades are also commonly used for municipal castings such as: Ductile iron manhole covers, Ductile iron drain grates, Ductile iron curb inlets.

Hopefully, the article on "What is ductile iron made from" has partially helped you gain more information about this type of iron. We hope this is useful to you.