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!