Q1: What is Wrought Iron?
Ans: Wrought iron is a pure form of iron with very low carbon content.
It is soft, ductile, and easily workable.
Q2: State the uses of Wrought Iron.
Ans: The uses are:
- ➔ Chains and hooks
- ➔ Pipes and tubes
- ➔ Decorative items
- ➔ Agricultural tools
Q3: State the properties of Wrought Iron.
Ans: The properties are:
- ➔ High ductility
- ➔ Good corrosion resistance
- ➔ Tough and malleable
- ➔ Low carbon content
- ➔ Easily welded
Q4: State the composition of Wrought Iron.
Ans: The composition is:
- ➔ Iron (Fe): about 99%
- ➔ Carbon (C): less than 0.1%
- ➔ Slag: small amount
Q5: Briefly explain the manufacturing of Wrought Iron.
Ans: Wrought iron is manufactured from pig iron using a puddling furnace.
Impurities and excess carbon are removed by heating and stirring.
The metal is then shaped into bars.
Q6: What is a Puddling Furnace? What is it used for?
Ans: A puddling furnace is a type of furnace used to convert pig iron into wrought iron.
It removes carbon and impurities by heating and stirring the molten metal.
Q7: What is a Reverbratory Furnace? What is it used for?
Ans: A reverberatory furnace is a furnace where heat is reflected from the roof onto the material.
It is used for heating metals without direct contact with fuel.
Q8: What is a Single Puddling Furnace?
Ans: A single puddling furnace has one working chamber where the metal is processed.
It is used for small-scale production.
Q9: What is a Double Puddling Furnace?
Ans: A double puddling furnace has two working chambers.
It increases production and efficiency.
Q10: What are the Charges of Puddling Furnace?
Ans: The charges of Puddling Furnace are as follows:
- ➔ Pig Iron
- ➔ Hot Air
- ➔ Iron Oxide
Q11: Briefly explain the Charging of Puddling Furnace.
Ans: Charging is the process of adding pig iron and other materials into the furnace.
The materials are heated until they become semi-molten.
Q12: Briefly explain the Operation of Puddling Furnace.
Ans: In operation, the molten iron is stirred continuously.
Oxygen reacts with carbon and impurities to remove them.
The metal becomes pasty and forms lumps.
Q13: Briefly explain the Construction of Puddling Furnace.
Ans: The puddling furnace consists of a hearth, firebox, chimney, and working door.
Heat is reflected from the roof onto the metal in the hearth.
Q14: What is the melting temperature of Pig Iron?
Ans: The melting temperature of pig iron is about 1200<sup>o</sup>C to 1500<sup>o</sup>C.
Q15: What are Puddlers Candles?
Ans: Puddlers candles are bright flames formed during the burning of carbon in the furnace.
They indicate the removal of impurities.
Q16: What are Puddle Balls?
Ans: Puddle balls are lumps of semi-solid iron formed during the puddling process.
These are later worked into shapes.
Q17: What is Squeezing or Shingling?
Ans: Squeezing or shingling is the process of removing slag from puddle balls by hammering or pressing.
It improves the quality of wrought iron.
Q18: What are Merchant Bars?
Ans: Merchant bars are finished wrought iron bars produced after rolling.
They are used for commercial purposes.
Q19: What is Ductility?
Ans: Ductility is the property of a material to be drawn into thin wires without breaking.
Q20: What is Purity?
Ans: Purity is the degree to which a material is free from impurities.
Q21: What is Fettling?
Ans: Fettling is the process of repairing and preparing the furnace lining.
It ensures proper working of the furnace.
Q22: What is the purpose of Fettling?
Ans: The purpose is:
- ➔ To protect the furnace lining
- ➔ To maintain proper working condition
- ➔ To increase furnace life
Q23: What is the Finery Process?
Ans: Finery process is an old method of refining pig iron into wrought iron.
It removes carbon by oxidation.
Q24: What is the Bloomery Process?
Ans: Bloomery process is an ancient method of producing iron from ore.
It produces a spongy mass called bloom.
Q25: Why is a puddling Furnace called a “Puddling” Furnace?
Ans: It is called a puddling furnace because the molten metal is stirred (puddled) continuously.
This helps in removing impurities and improving quality.
