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Ferro Silicon Magnesium Alloy is used for production of Spheroidal Graphite Iron. The presentation gives insight for Why S.G. Iron is used? and Application of FeSiMg alloy in the production of S.G. Iron.
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Master Alloy – FeSiMg a précis
What is steel and
Iron?
Steel Alloy ofFe & C
C = 0.2% to 2.1%
Iron Element
abundant in earths crust
Alloy of Fe, C & Si
Cast Iron
C = 1.7 to 4.3%Si = 0.5 to 3%
Iron-Iron Carbide diagram
Liquid
Austenite
a + Fe3C
d
g+ L
a + g
L + Fe3C
723˚C
910˚C
0% 0.8% ~2% ~3%
a
g + Fe3C
Carbon wt %
Tem
p C Cast IronSteel
Steel
Forms usedCables / Structures / Wires / Cutting Tools / Armor / Springs / Rails
Mild SteelHigh Carbon SteelLow Carbon SteelStainless SteelHigh Speed Steel
Cast Iron
Forms usedPipes / Machines / cylinder heads / cylinder blocks / gear boxes
GrayWhite
Malleable Ductile
What is SG iron?
Mechanical PropertiesCast Iron
ASTM A48 Class 25
Ductile IronASTM A395
Cast Steel
ASTM A216Grade WCB
Tensile Strength, Min psi
25,000 60,000 80,000
Yield Strength, Min psi Negligible 40,000 36,000
Elongation, Min % in 2” Negligible 12 – 18% 22 – 30%
Cost of Production Less Moderate High
Flakes to Nodules formation - addition of nodularizing elements like Mg/Ce
Cast Iron
S G Iron
Nodularizing – Mechanism Nodularizing is a simultaneous desulphurizing & deoxidizing
Mg + S= MgS --------- Desulphurization Mg + O = MgO ------- DeoxidationMg + Si + 3O = MgSiO3
2Mg + Si + 4O = Mg2SiO4
After this the growth of graphite proceed as nodules
Graphite
Orthorhombic Irregular shape
Increased under cooling
Spheroidal
As the solidification velocity increases with time the graphite flakes are converted to spheroids
After Mg Treatment
Production Process
SG Iron?
Sandwich Cover Process
Plunger Process
Inmould Process
Cored Wire Treatment Process
FeSiMg / Mg wire
Treatment ladle (covered)
Role of Alloying Elements- FeSiMg alloy
Mg
12
Magnesium allows to precipitate graphite in the form of nodules
RE
58
Rare earth reduces the negative effects of trace elements like Ar/Bi/Ti/Pb, forms intermetallic, also reduce sulphur
Ca
20
Reduces the reactivity of Mg and thus minimizing the fumes emission
Initiate the modification process by reacting with S and O forming sulfide and silicate phase
Role of Alloying Elements- FeSiMg alloy
Al
13
Aluminium in reduces undercooling and shrinkage tendency
Parameters for
FeSiMg alloy performance
Composition of FeSiMg
Alloy
Slag in Furnac
e
Alloy Cove
r
Ladle Design (D:H)
Time between
treatment and
pouring
Tapping Temp
Sulphur
content
Approximate Addition % of FeSiMg alloy
1.2High Ca&Re FeSiMg alloy
Very low Good 1:2 1 min 1460°C0.005
%
1.7Low Ca&Re FeSiMg alloy
High No 1:1 8 min 1500°C0.015
%
Parameters
Sources & Effect of impurities
Elements Effects Sources Max Limit %Lead Can reduce tensile Strength,
Promotes pearlitepaints, freecuttingsteels, nonferrous alloys,
0.002
Antimony Degenerate Graphite nodules white metal, solder, some pig irons
0.005
Bismuth Promotes carbides and undesirable graphite forms that reducetensile properties
Bismuth containingmolds and core coatings
0.002
Titanium Promotes undercooled graphite.
Some pig irons, steel scrap,
0.05
Aluminum Promotes hydrogen pinhole defects
ferrous alloys,inoculants, scrap
0.6
Present Market Potential & Minex Presence
64000MT/Year
30000MT/Year
14000MT/Year
World Casting Production Data
Top Casting Producers
Europe 12 million tons
Japan4.4 million tons
Russia4.2 million tons
China35.3 million tons
India7.4 million tons
Brazil2.3 million tons
North America9.6 million tons
China India US Japan Russia
5
10
15
20
Gray Iron Ductile Iron
Millio
n T
on
s
Gray Iron vs. Ductile Iron
65%
35%
ApplicationsSG Iron
Transmission Main
Housing
V-Rod Cylinder
Head
Grey Iron Spun Pipes
Sprocket Wheel
Flexible Coupling
Truck Crankshaft / Engine
Rolling Mill Rolls
Rail Clips and Clamps
Break Pads / Liners
Nuclear Fuel Containers
Low Pressure Turbine Casing
And Many More
excellent machining, dampening capacity
Good wear characteristics compressive Strength
And advantage in areas of cost
thankyou!