presentation- iron carbon diagram

8/12/2019 Presentation- Iron Carbon Diagram

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In the physical sciences , a phase is a region of space (a thermodynamicsystem ), throughout which all physical properties of a material areessentially uniform. [1] Examples of physical properties include density ,index of refraction , and chemical composition. A simple description is that aphase is a region of material that is chemically uniform, physically distinct,and (often) mechanically separable. In a system consisting of ice andwater in a glass jar, the ice cubes are one phase, the water is a secondphase, and the humid air over the water is a third phase. The glass of the

jar is another separate phase.The term phase is sometimes used as a synonym for state of matter . Also,the term phase is sometimes used to refer to a set of equilibrium statesdemarcated in terms of state variables such as pressure and temperatureby a phase boundary on a phase diagram . Because phase boundariesrelate to changes in the organization of matter, such as a change fromliquid to solid or a more subtle change from one crystal structure toanother, this latter usage is similar to the use of "phase" as a synonym forstate of matter.

What Is PhasePhase (matter) , is state of matter
http://en.wikipedia.org/wiki/Physical_sciencehttp://en.wikipedia.org/wiki/Thermodynamic_systemhttp://en.wikipedia.org/wiki/Thermodynamic_systemhttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Refractive_indexhttp://en.wikipedia.org/wiki/State_of_matterhttp://en.wikipedia.org/wiki/Phase_diagramhttp://en.wikipedia.org/wiki/Phase_(matter)http://en.wikipedia.org/wiki/Phase_(matter)http://en.wikipedia.org/wiki/Phase_diagramhttp://en.wikipedia.org/wiki/State_of_matterhttp://en.wikipedia.org/wiki/Refractive_indexhttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Thermodynamic_systemhttp://en.wikipedia.org/wiki/Thermodynamic_systemhttp://en.wikipedia.org/wiki/Physical_science


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0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0

1000

1600

1400

1200

800

600

400

200

0

T e m p e r a

t u r e

i n C

910C-Ac31147C

Ac1-727C

1495C

1539C

2.11

0.022

0.008

0.8

4.3

0.1

0.54 0.18

L + Austenite

- Ferrite

Austenite ( ) Liquid Iron+ Cementite

Ledeburite + Cementite

Ledeburite + Cementite

Austenite + Cementite+ Ledeburite

Ferrit e

+Pearlite

Pearlite+

CementitePearlite + Cementite

+ Ledeburite

1 0 0

% P

e a r l

i t e

1 0 0 %

L e

d e

b u r i

t e + Fe3C

+ Liquid Iron + -Fe

-Fe

+ -Fe

Eutectic Point

Peritectic Point

Eutectoid PointSteel Cast Iron

Carbon %


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It is also known as (g ) gamma-iron,which is an interstitial solid solution ofcarbon dissolved in iron with a facecentered cubic crystal (F.C.C) structure.Average properties of austenite are:

Tensile strength 150,000 psi.

Elongation 10 % in 2 in gagelength.

Hardness Rockwell C 40

Toughness High

Austenite is normally unstable at roomtemperature. Under certain conditions it ispossible to obtain austenite at roomtemperature.

Austenite ( Y Iron)


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It is also known as (a ) alpha -iron,which is an interstitial solid solutionof a small amount of carbon dissolvedin iron with a Body Centered Cubic(B.C.C.) crystal structure. It is thesoftest structure on the iron-iron

carbide diagram. Average propertiesare:

Tensile Strength 40,000 psi

Elongation 40 % in 2 in gage length

Hardness Less than Rockwell C 0 or lessthan Rockwell B 90.

Toughness Low

Alfa Ferrite


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It is the eutectoid mixture containing0.83 % Carbon and is formed at 723C

on very slow cooling. It is very fineplatelike or lamellar mixture of ferriteand cementite. The structure ofpearlite includes a white matrix(ferritic background) which includesthin plates of cementite. Average

properties are:

Toughness Low

Tensile

Strength

120,000 psi

Elongation 20 % in 2 in gage length

Hardness Rockwell C 20 or BHN 250-300

Pearlite


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It is the eutectic mixture of austenite and cementite. Itcontains 4.3 % Carbon and represents the eutectic of

cast iron. Ledeburite exists when the carbon content isgreater than 2 %, which represents the dividing line onthe equilibrium diagram between steel and cast iron.

Ledeburite ( Y +Fe 3C) or (P + Fe 3C)


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(d ) DELTA IRON:

Delta iron exists between 1401 and 1495 C . It may exist incombination with the melt to about 0.50 % Carbon, incombination with austenite to about 0.18 % Carbon and in asingle phase state out to about 0.10 % carbon. Delta iron hasthe Body Centered Cubic (B.C.C) crystal structure and ismagnetic.

presentation- iron carbon diagram

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