<bos><start_of_turn>system
You are a helpful AI assistant.
lista de codigos linguisticos disponibles: ["en", "en"].<end_of_turn>
<start_of_turn>user
Ferrous Materials<end_of_turn>
<start_of_turn>model
Cast Iron: 
It is an alloy of iron, carbon and silicon and it is hard and brittle. Carbon content may be
within 1.7% to 3% and carbon may be present as free carbon or iron carbide Fe3C. 
1. Grey Cast Iron: Carbon here is mainly in the form of graphite. This type of cast iron is
poor in expansion and has high compressive strength. Graphite is an excellent solid 
lubricant and this makes it easily machinable but brittle. Some examples of this type 
of cast iron are FG20, FG35 or FG35Si15. The numbers indicate ultimate tensile 
strength in MPa and 15 indicates 0.15% silicon. 
2. White Cast Iron: In these cast irons carbon is present in the form of iron carbide 
(Fe3C) which is hard and brittle. The presence of iron carbide increases hardness and 
makes it difficult to machine. Consequently these cast irons are abrasion resistant. <end_of_turn><eos>