1. Wrought Iron

2. Introduction
Wrought iron is a mechanical mixture of very pure iron and a silicate slag.
Wrought iron is a ferrous material, aggregated from a solidifying mass of pasty particles of highly refined metallic iron with which a minutely and uniformly distributed quantity of slag is incorporated without subsequent fusion.

3. Chemical composition C – 0.02% - 0.03% P – 0.05% - 0.25%
Mn – Nil-0.02%
Slag – 0.05%-1.50%
Iron - Balance

4. Properties W.I is never cast.
Shaping is accomplished by hammering pressing and forging.
High ductility
Can be forged and Welded.
Ultimate tensile strength of W.I. can be increased considerably by cold working followed by a period of aging.
W.I. possesses a high resistance towards the corrosion.
W.I. possesses the property of recovering rapidly from overstrain, which enables it to accommodate sudden and excessive shocks without permanent injury.

5. High resistance towards fatigue.
Property
Value
Ultimate tensile strength [psi (MPa)]
34,000–54,000 (234–372)
Ultimate compression strength [psi (MPa)]
Ultimate shear strength [psi (MPa)]
28,000-45,000 ( )
Yeild point [psi (MPa)]
23,000–32,000 (159–221)
Elongation, % in 200 mm
18-25
Modulus of elasticity (in tension) [psi (MPa)]
28,000,000 (193,100)
Melting point [°F (°C)]
2,800 (1,540)

6. Uses and Application
Building Construction: Underground services lines and electrical conduit. Soil, waste, vent and downspout piping.
Public Works: Bridge railings, blast plates, drainage lines, and troughs, sewer outfall lines, weir plates, sludge tanks and lines.
Industrial: Condenser tubes, unfired heat exchanges, acid and alkali process lines, skimmer bars.
Rail road and marine: Diesel exhaust and air brake piping, ballast and brine protection plates, hull and deck planting, tanker heating coils etc.
Others : Gas collection hoods, coal handling equipment, cooling tower and spray pond piping.

7. Cast Iron

8. ORE
Blast Furnace
PIG IRON
CUPOLA FURNACE
CAST IRON

9. White CI Grey CI CAST IRONS Ductile CI Malleable CI Alloy CI
Malleabilize
Grey CI
CAST IRONS
Stress concentration at flake tips avoided
Ductile CI
Good castability  C > 2.4%
Malleable CI
Alloy CI

10. Gray Cast Iron
Gray cast iron is characterized by its graphitic microstructure, which causes fractures of the material to have a gray appearance.
It is the most commonly used cast iron and the most widely use cast material base on weight.
Most cast irons have a chemical composition of 2.5 to 4.0% carbon, 1 to 3% silicon, and the remainder is iron.
Gray cast iron has less tensile strength and shock resistance than steel.
Its compressive strength is comparable to low and medium carbon steel.

11. Gray Cast Iron
A low cost material that can be used for many purposes

12. Characteristics:
Gray Iron basically is an alloy of carbon and silicon with iron.
It is readily cast into a desired shape in a sand mould.
It contains % C, %Si, 0.4-1%Mn, 0.15% P and 0.10% S.
It is marked by the presence of flakes of graphite in a matrix of ferrite, pearlite and austenite.
Graphite flakes occupy about 10% of the metal volume
Length of flakes may vary from 0.05 mm to 0.1 mm
When fractured, a bar of Gray Cast Iron gives gray appearance

13. Gray iron possesses lowest melting point of the ferrous alloys.
G.C.I. possesses high fluidity and hence it can be cast into complex shapes and thin sections.
It possesses machinability better than steel.
It has higher resistance to wear
It possesses high vibration damping capacity
Gray iron has low ductility and low impact strength as compared with steel.
G.C.I. has a solidification range of 2400 – 2000°F
It associates low cost combined with hardness and rigidity.

14. G.C.I. possesses high compressive strength
G.C.I. possesses excellent casting qualities for producing simple and complex shapes.

15. Application Machine tools and structures (bed, frame and details)
Gas or water pipes for underground purpose
Manhole covers
Cylinder blocks and heads for I.C. engines
Tunnel segments
Frames for electric motors
Ingot moulds
Sanitary Wares
Piston Rings

16. Malleable Cast Iron
Malleable iron: dark graphite rosettes (temper carbon) in an –ferrite matrix

17. Malleable Cast Iron
Malleable iron starts as a white iron casting, that is then heat treated at about 900 °C (1,650 °F).
Graphite separates out much more slowly in this case, so that surface tension has time to form it into spheroidal particles rather than flakes.
In general, the properties of malleable cast iron are more like mild steel

18. Characteristics:
M.C.I. is one which can be hammered and rolled to obtain different shapes.
M.C.I. is obtained from the hard and brittle white iron through a controlled heat conversion process.
(i) A ferritic M.C.I. has Ferrite matrix
(ii) A pearlitic M.C.I. has pearlite matrix
(iii) An alloy M.C.I. contains chromium and nickel and possess high strength and corrosion resistance.
4) M.C.I. possess high yield strength.
5) High young’s modulus and low coefficient of Thermal expansion.

19. Malleable Iron Pearlitic Matrix Ferritic Matrix Ferrite (White)
Graphite (black)
Pearlite (grey)
Partially Malleabilized Iron  Incomplete Ferritizing Anneal
Ferritic Matrix
Ferrite (White)
Graphite (black)
10 m
Fully Malleabilized Iron  Complete Ferritizing Anneal

20. 6) Good wear resistance and vibration damping capacity.
7) Can be used from – 60 to 1200°F
8) Solidification range of °F
9) Low moderate cost.
10)M.C.I. contains 2-3% C, % Si, % Mn, 0.15% P and 0.10% S.

21. Application Automotive Industry Rail Road Agricultural implements
Electrical line Hardware
Conveyor chain links
Gear case
Universal joint yoke
Rear axle banjo housing
Automotive crankshaft.

22. Spheroidal Cast Iron
Nodular (ductile) iron: the dark graphite nodules are surrounded by an -ferrite matrix.

23. Spheroidal Cast Iron
Nodular or ductile cast iron. Tiny amounts of magnesium or cerium added to these alloys slow down the growth of graphite precipitates by bonding to the edges of the graphite planes.
Along with careful control of other elements and timing, this allows the carbon to separate as spheroidal particles as the material solidifies.
The properties are similar to malleable iron, but parts can be cast with larger sections.

24. Characteristics:
Unlike long flakes as in G.S.I., graphite appears as rounded particles, or nodules or spheroids in N.C.I.
Ductile cast iron possesses very good machinablity.
Soft annealed grades of S.C.I. can be turned at very high feeds and speeds.
The properties of S.C.I. depend upon the metal composition and the cooling rate.
Spheroidal or Nodular or Ductile C.I. contains 3.2%-4.2% C, 1.1%-3.5% Si, 0.3% - 0.8% Mn, 0.08% P and 0.2% S.
It possesses excellent damping capacity, casteblity and wear resistance.

25. Mechanical Properties of SG Iron

26. Application Paper industries machinery I. C. engines
Power transmissions equipment
Farm implements and tractors
Earth moving machinery
Valves and fittings
Steel mills rolls and mill equipment
Pipes
Pumps and compressors

27. White Cast iron
White iron: the light cementite regions are surrounded by pearlite, which has the ferrite–cementite layered structure.

28. White cast iron
With a lower silicon content and faster cooling, the carbon in white cast iron precipitates out of the melt as the metastable phase cementite, Fe3C, rather than graphite.
The cementite which precipitates from the melt forms as relatively large particles, usually in a eutectic mixture, where the other phase is austenite (which on cooling might transform to martensite).
It is difficult to cool thick castings fast enough to solidify the melt as white cast iron all the way through.
However, rapid cooling can be used to solidify a shell of white cast iron, after which the remainder cools more slowly to form a core of grey cast iron.

29. Characteristics:
W.C.I. derives its name from the fact that its freshly broken surface shows a bright white fracture.
Unlike gray iron, W.C.I. has almost all its carbon chemically bonded with the iron- as iron carbide, Fe3C which is very hard and brittle constituent.
W.C.I. possesses excellent abrasive wear resistance.
W.C.I. under normal circumstances is brittle and not machinable.
By using a fairly low silicon content, cast iron may be made to solidify as white iron.
W.C.I. casting can be made in sand moulds.
W.C.I. can also be made on the surface of a gray iron casting provided the material is of special composition.

30. If iron of proper composition is cooled rapidly, the free carbon will go in the combined form and give rise to white iron casting.
W.C.I. contains % C, 0.5 – 2.0% Si, % Mn, 0.18% P and 0.10% S.
The solidification range of W.C.I. is °F

31. Application For producing malleable iron casting
For manufacturing those component parts which require a hard and abrasion resistant material.

32. Thank you