pig-iron and Cast Iron-ITI-FITTER ONLINE NOTE

Introduction of pig-iron

i)- Metal which contain Iron as a Major  content  Are called ferrous metal.

ii)- There are different types of ferrous metal : (1) Pig Iron (2) Cast Iron (3) Wrought Iron and (4) Steel 

1)- Pig Iron:-   

(I) Pig Iron Is obtained by the chemical reduction of Iron ore. 

(Ii) The process of reduction of The Iron ore To Pig Iron Is Known as smelting .

(Iii) The raw materials required for Producing Pig Iron 

(A) Iron Ore (B) Coke (C) Flux

a)- Iron Ore:-

(I) The chief Iron Ores Used Are  : (A) Magnetite (B) Hematite (C) Limonite (D) Carbonate 

(Ii) The Separation Of Iron From Iron Is achieved By smelting It With Core and limestone In a blast furnace. 

(b)- Coke:- : 

(I) Core Is the fuel used to give necessary hit to carry on the reducing action .

(Ii) The carbon from the core In the form of carbon monoxide combines with the Iron Ore to reduce It to Iron. 

(c)- Flux:- :  

(I)  This Is The Mineral Substance Charged Into A Blast Furnace To Lower The Melting Point Off The Ore .

(Ii) Limestone Is The Most Commonly Used Flux In The Blast Furnace. 

Blast furnace  : 

(I) The Furnace Used For Smelting Iron Ore Is The Blast Furnace. 

(Ii) The Product Obtained From Smelting In The Blast Furnace Is Pig Iron. 

(Iii) The Main Part Of The Blast Furnace Ore 

(A) Thread (B) Stack (C) Bosh (D) Hearth  (E) Double Bell Charging Mechanism (F) Layers

(Iv) The Raw Materials Are Charged In Alternate Layers Of Iron Ore , Core And Flux In The Furnace By Means Of A Double Bell Mechanism. 

(V) The Hot Blast Is Forced Into The Furnace Through A Number Of Nozzles Called Layers 

(Vi) Iron Ore Melting Starting In Furnace 1000`C To 1700`C 

(Vii) The Iron And Slag Are To Catch To Separately At Different Intervals.

 Blast Furnace

 Note :- The Pig Iron Is, Therefore Refined And Re Melted And Used To Produced Other Varieties Of Iron And Steel.

2)- Cast Iron:-  

i)- Pig Iron Is Re Melted Is A Cupola For The Production Of Cast Iron And Molded  Into Required Shapes 

(Ii) Cast Iron Is An Alloy Of Iron, Carbon , Silicon 

(Iii) The Carbon Content  Ranges From 2% To 4% 

(Iv) It Is Produced By Cupola Furnace .

(V) Cupola Furnace Consist Pig Iron , Core , Limestone ,Steel scrap.

vi)- Steel scrap used in cupola furnace reduced the carbon contain.

CUPOLA FURNACE

Types Of Cast Iron:-  

(I) Grey Cast Iron  (Ii) White Cast Iron (Iii) Malleable Cast Iron (Iv) Nodular Cast Iron 

(I) Gray Cast Iron:- 

(i)  This Type Of Cast Iron Is Mostly Used For Casting .

(ii) Its Melting Point 1150`C To 1200`C. 

(Iii) It Can Be Used Any Type Of Parts.

(Iv) Its Tensile Strength 1250 Kg/Sq C.M 

(V) Its Compressive Strength 6250 kg/Sq C.M 

(Vi) Machine Bases Slide ways Are Made Of Cast Iron 

(Vii) Grey Cast Iron Has A Graphite Micro Structure 

(Viii) Its Colours Is Gray Because Its Mixed In Graphite Content 

2)- White Cast Iron:-

(I) White Cast Iron Is Very Hard And Bright 

(Ii) This Is Mainly Used In The Manufacturer Of Wrought Iron 

(Iii) It Is Four Mechanical Properties 

(Iv) It Is Not Easily To Cut 

(V) It Is Used For Rough Casting Like Main Hole Cover , Water Pipe , Electrical Fitting 

(Vi) Its Other Name Is Chiled Cast Iron 

(Vii)  White Cast Iron Cant Be Welded 

3)- Malleable Cast Iron:-  

i)- Malleable Cast Iron Is Produce From White Cast Iron By A Prolonged Hit Treatment Process About 30 Hours.

ii)- Malleable cast iron has increased ductility, tensile strength and toughness when compared with grey cast iron. 

4)- Nodular cast iron:- 

i)- It is also like malleable cast iron but it does not require heat treatment. 

ii)- It has good wear resistance and machinable. 

iii)- It has low melting point. 

iv)- Malleable and modular cast iron are mostly used for high tensile stress and impact loading machine parts casting.

v)- It is also called modular iron, ductile iron,spheroidal graphite iron.