JC Casting - Ductile Iron Casting

Ductile iron is also known as ductile cast iron, Spheroidal Graphite Iron. It essentially is an iron-carbon alloy. The carbon content in cast iron is greater than 2%. Ductile Iron contains spheroidal (nodular) shaped graphite. It is higher strength than Gray Iron. weighs about 10% less than steel for the same section size.

Ductile Iron castings are produced for applications requiring strength, toughness, good machinability, and low cost. So important elements like silicon, manganese, sulfur, phosphorus, etc. can be added to the cast iron. That changes the structure and properties of the resulting alloys.

Ductile cast iron (also called spheroidal graphite cast iron or nodular cast iron) has been widely used as the main industrial material in place of high-grade cast iron. Although most varieties of cast iron are comparatively brittle, ductile iron castings are much more ductile due to the inclusion of nodular graphite.

Ductile Iron Castings Microstructure

Ductile iron, also referred to as nodular cast iron or spheroidal graphite iron, has an unusual combination of properties obtained because the graphite occurs as spheroids rather than flakes as in gray iron. This mode of solidification is obtained by adding a very small but specific amount of magnesium to molten iron. The allowable content of minor elements that can interfere with the graphite spheroid formation in the base iron is severely restricted. The added magnesium reacts with the sulfur and oxygen in the molten iron and changes the way the graphite is formed.

• high strength, ductility and wear resistance. These qualities allow for a much higher tensile and yield strength as well as a lower damping capacity.
• low melting point, good fluidity and machinability. superior castability and machinability.
  excellent strength to weight ratio.
  Ductile iron casting cost is lower than steel castings.
• Compared to grey iron casting, ductile iron has much more impact and fatigue resistance
• Near net shape, ductile iron investment castings provide the design engineer with the best combination of part design, surface hardening ability, elasticity modulus, corrosion resistance, and strength versus weight ratio.

Ductile iron castings have many useful characteristics and cost-effective alternatives to other ferrous alloys. Additionally, ductile irons are widely used in numerous industries including:

Aerospace
Manufacturing
Agriculture
Automotive

Due to their increased strength and ductility, Ductile Iron Casting products:

• Valve Bodies
• Compressor Valves
• Couplings
• Sprocket Wheels
• Hydraulic Valves & Cylinders
• Structural Brackets
• Rollers
• Cable Drums
• Frames
• Pumps
• Crankshafts
• Camshafts
• Exhaust Manifolds
• Machine frames
• Flanges
• Hubs
• Gear Boxes