What are the basic structures of iron carbon alloys?
The symbol is A. The stable austenite has a temperature of 727 DEG C, when the solubility of carbon is 0.77%, the strength, hardness and plasticity of austenite are very good, which is the organization required for high temperature forging or rolling of most steels.Cementite: a metallic compound of iron and carbon with a carbon content of 6.69%. The formula Fe3C is expressed in symbolic Cm. High hardness, poor plasticity, hard and brittle, the number of cementite increases, strength and hardness increase, while plasticity decreases.
Ferrite: a solid solution in which carbon is dissolved in alpha -Fe, called ferrite. The symbol is Fe. Ferritic carbon content is very low, at 727 degrees of 0.0008%, and its mechanical properties similar to pure iron, strength and hardness is not high, plasticity and toughness good.Austenite: a solid solution in which carbon is dissolved in gamma -Fe, called austenite.
Pearlite: a mixture of ferrite and cementite, expressed in P. Microscopically, the cementite and the ferrite lamellae alternate with each other. Under equilibrium conditions, the carbon content of pearlite is 0.77%, and its strength is high. The plasticity, toughness and hardness of pearlite are between cementite and ferrite.A mixture of austenite and cementite at high temperatures, expressed in Le. Its mechanical properties are similar to those of cementite, with high hardness and poor plasticity.Ferrite, austenite and cementite are the basic phases of iron carbon alloy in the five kinds of structures.
