Cementite is a chemical compound of carbon with iron and is known as iron carbide fe3c. Fcc has larger interstitial positions mechanical properties. Fe3c iron carbide called cementite because it is hard. It is used for drainage culverts, roofing, and ducts etc. Some special alloys can exist in more than one phase at the same temperature. The ironcarbon diagram there are two ironcarbon equilibrium diagrams.
The ironiron carbide fefe 3c phase diagram ferrite. Methods used to distinguish between freeferrite and freecementite 6. Introduction to the ironcarbon equilibrium diagram 2. Introduction to the fefe3c equilibrium diagram phases in fefe3c. Iron carbon phase diagram with detailed explanation. The part of ironcarbon alloy system diagram between pure iron and an interstitial compound, iron carbide fe3c, containing 6.
Free cementite is found in all steel containing more than 0. The fec phase diagram is a fairly complex one, but we will only consider the steel part of the diagram, up to around 7% carbon. Trick to remember iron carbide diagram for any exam duration. In their simplest form, steels are alloys of iron fe and. It increases with increase in carbon % as reflected in fec equilibrium diagram. It should first be pointed out that the normal equilibrium diagram really represents the metastable equilibrium between iron and iron carbide cementite. In fact, the compound iron carbide decomposes into iron and carbon graphite. Equilibrium phase diagrams show the regions of existence and the composition of equilibrium phases, as a function of the components present in the system. In general, littleattention is given to theapplication of phase diagrams to multicompo nent solid state systems. Iron carbon equilibrium diagram complete discussion with interview questions if you have an doubt then please write in the comment box. The ironcarbon equilibrium diagram total materia article. Bcc cementite fe 3c eutectic, peritectic, eutectoid iron, ferrite c iron carbon diagram provides a valuable foundation on which to build knowledge of both plain carbon and alloy steels in their immense variety. The ironiron carbide equilibrium diagram practical maintenance.
Compulsory,2 marks will be given from this iron carbon diagram theory in any exam. The iron iron carbide fefe3c phase diagram in their simplest form, steels are alloys of iron fe and carbon c. Ironcarbon phase diagram explained with graphs fractory. With frame as pdf go to science of welding steel go to 8. Martensite non equilibrium bct phase from quench of. It may be noted that though it is called as equilibrium diagram, it is not a true equilibrium diagram, since equilibrium implies no change of phase with time. Cementite is a metastable phase, which decomposes to graphite if given long periods of time. If the percentage of the carbon is in the range of 0 to 2. The ironiron carbide equilibrium diagram cast iron steel. Ironcementite diagram is not a true equilibrium diagram, since equilibrium means no change of phase with time, however long it may be.
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