What is the microstructure of white cast iron?
The microstructure of white CI contains massive cementite (white) and pearlite. White cast iron derives its name from the white, crystalline crack surface observed when a casting fractures. Most white cast irons contain less than 4.3% carbon, with low silicon contents to inhibit the precipitation of carbon as graphite.
How is white cast iron formed?
White cast iron is formed when the carbon in solution is not able to form graphite on solidification. White cast irons are hard and brittle; they cannot easily be machined. They are unique in that they are the only member of the cast iron family in which carbon is present only as a carbide.
What is hardening of cast?
In hardening gray iron, the casting is heated to a temperature high enough to promote the formation of austenite, held at that temperature until the desired amount of carbon has been dissolved, and then quenched at a suitable rate.
Why does white cast iron appear white?
Corrosionpedia Explains White Cast Iron White cast iron displays white colored cracks when it fractures due to carbide impurities. The carbon content within the cast iron precipitates large molecules that increase its hardness and durability.
What are the advantages of GREY cast iron?
Advantages of Gray Cast Iron
- Low Cost.
- Good Vibration/Damping Capability.
- Excellent Compressive Strength.
- Ability to Withstand Thermal Cycling.
- Tensile Strength.
- Deformation Resistance.
- Low Melting Point.
- Oxidation Resistance.
What is the microhardness of white cast iron?
The microstructure of Pearlitic white cast iron is shown above. The pearlitic structure can, also, be possible with a high concentration of alloy. With a variation of solidification processes and composition, microhardness and microstructure of Pearlitic white cast iron may vary.
What is the process of case hardening wrought iron?
The wrought iron, with nearly no carbon in it, was very malleable and ductile but not very hard. Case-hardening involves packing the low-carbon iron within a substance high in carbon, then heating this pack to encourage carbon migration into the surface of the iron.
What makes white cast iron so hard and brittle?
White iron is extremely hard and brittle. The answer lies in its microstructure. The microstructure consists of a thick continuous network of carbides embedded in the Pearlitic or martensitic matrix. This carbide network is extremely hard and resists any plastic deformation. This is the main reason for white cast iron to be hard and brittle.
How are case depth and hardness related in induction hardening?
written in terms of hardness . Induction hardening specification s usually call out a surface hardness and effective case depth, with the as- sumption that the hardness correlates to the properties needed in the com- ponent. However, for a given mate- rial, the hardness correlates with other material properties only for a partic-