Q1: Define Ferrous Metals. Name some.
Ans: Ferrous metals are metals that contain iron as their main element.
Some examples are:
- ➔ Steel
- ➔ Cast Iron
- ➔ Wrought Iron
Q2: Define Non-Ferrous Metals. Name some.
Ans: Non-ferrous metals are metals that do not contain iron.
Some examples are:
- ➔ Aluminium
- ➔ Copper
- ➔ Zinc
- ➔ Lead
Q3: Briefly explain the welding of Ferrous Metals.
Ans: Welding of ferrous metals is generally easier because they contain iron and have good weldability.
However, proper temperature control is required to avoid cracks and distortion.
Q4: Briefly explain the welding of Non-Ferrous Metals.
Ans: Welding of non-ferrous metals is more difficult because they have lower melting points and high thermal conductivity.
Special techniques and care are required to avoid defects.
Q5: What is Pre-heating?
Ans: Pre-heating is the process of heating the metal before welding to a specific temperature to improve weld quality.
Q6: State the methods of Pre-heating.
Ans: The methods of pre-heating are:
- ➔ Blow pipe flame heating
- ➔ Electrical heating
- ➔ Furnace heating
- ➔ Mechanical heating
Q7: State any two purposes of Pre-heating.
Ans: The purposes are:
- ➔ To reduce cracking in welds
- ➔ To improve weld strength
Q8: Briefly explain Preheating with Blow Pipe Flame.
Ans: In this method, a blow pipe flame is used to heat the metal surface before welding.
It is simple and commonly used for small jobs.
Q9: What is Peening?
Ans: Peening is a process of hammering the welded metal to relieve internal stresses and improve strength.
Q10: Briefly explain the method of Peening.
Ans: In peening, the weld is lightly hammered while it is still hot.
This helps to reduce stress and prevent cracks.
Q11: What is Spot Heating?
Ans: Spot heating is a process of heating a small specific area of metal to control distortion or relieve stress.
Q12: Briefly explain the method of Spot Heating.
Ans: In spot heating, heat is applied to a small area using a flame.
The heated area expands and helps in correcting distortion.
Q13: Briefly explain the mechanical method of preheating.
Ans: In the mechanical method, heat is generated by mechanical means such as friction or external devices.
It is used when uniform heating is required.
Q14: Briefly explain Welding of Cast Iron.
Ans: Welding of cast iron is difficult due to its brittle nature and high carbon content.
Pre-heating and slow cooling are required to avoid cracks.
Q15: What is Cast Iron?
Ans: Cast iron is a ferrous metal that contains a high percentage of carbon, making it hard and brittle.
Q16: What is Grey Cast Iron?
Ans: Grey cast iron is a type of cast iron that has graphite flakes in its structure, giving it a grey appearance and good machinability.
Q17: What is Welding Flux?
Ans: Welding flux is a chemical substance used during welding to prevent oxidation and remove impurities from the weld area.
Q18: What is a Gas Welding Rod?
Ans: A gas welding rod is a filler metal used in gas welding to join two metal pieces together.
Q19: What is Flux?
Ans: Flux is a chemical substance used to clean and protect metal surfaces during welding or soldering.
It prevents oxidation and helps in smooth joining of metals.
Q20: What is Welding Flux?
Ans: Welding flux is a material used during welding to remove oxides and impurities from the metal surface and protect the weld from atmospheric contamination.
Q21: Name the flux used in the Welding of Aluminium?
Ans: The flux used in aluminium welding is:
Q22: What is Welding?
Ans: Welding is a process of joining two or more metal parts by heating them to a suitable temperature with or without pressure and filler material.
Q23: State the procedure of Welding.
Ans: The welding procedure is as follows:
- ➔ Clean the metal surface
- ➔ Set the welding equipment
- ➔ Strike the arc or ignite the flame
- ➔ Melt the base metal and filler rod
- ➔ Form the weld joint
- ➔ Allow it to cool properly
Q24: Briefly explain the welding of Aluminium and its alloys.
Ans: Welding of aluminium and its alloys is difficult because of oxide layer and high thermal conductivity.
Proper cleaning, correct flux, and controlled heat are required to get a good weld.
Q25: What is TIG Welding?
Ans: TIG welding (Tungsten Inert Gas welding) is a process that uses a non-consumable tungsten electrode and inert gas to produce a clean and strong weld.
Q26: What is MIG Welding?
Ans: MIG welding (Metal Inert Gas welding) is a process that uses a consumable wire electrode and shielding gas to join metals.
Q27: State any two uses of Filler Rod.
Ans: The uses are:
- ➔ To fill the gap between metal parts
- ➔ To strengthen the weld joint
Q28: Briefly explain the welding of Copper.
Ans: Welding of copper is difficult due to its high thermal conductivity.
Pre-heating and proper flux are required to avoid heat loss and ensure a strong weld.
Q29: State any four properties of Copper.
Ans: The properties are:
- ➔ High electrical conductivity
- ➔ High thermal conductivity
- ➔ Good corrosion resistance
- ➔ Ductile and malleable
Q30: State the methods used for the welding of Copper.
Ans: The methods are:
- ➔ Gas welding
- ➔ Arc welding
- ➔ TIG welding
- ➔ MIG welding
Q31: Briefly explain the construction of TIG Welding Machine.
Ans: A TIG welding machine consists of a power source, torch, electrode, shielding gas supply, and control unit.
It is designed to produce a stable arc using a tungsten electrode.
Q32: State the parts of TIG Welding Machine.
Ans: The parts are:
- ➔ Power supply
- ➔ Tungsten electrode
- ➔ Torch
- ➔ Gas cylinder
- ➔ Regulator
- ➔ Work clamp
Q33: State any four advantages of TIG Welding.
Ans: The advantages are:
- ➔ High quality weld
- ➔ Clean and neat appearance
- ➔ No slag formation
- ➔ Suitable for thin materials
Q34: State the disadvantages of TIG Welding.
Ans: The disadvantages are:
- ➔ High cost of equipment
- ➔ Requires skilled operator
- ➔ Slower process
- ➔ Not suitable for thick metals
Q35: What are TIG Torches?
Ans: TIG torches are tools used in TIG welding to hold the tungsten electrode and supply shielding gas to the welding area.
Q36: State the parts of TIG Torches.
Ans: The parts of TIG torches are:
- ➔ Tungsten electrode
- ➔ Nozzle
- ➔ Collet
- ➔ Gas lens
- ➔ Torch body
Q37: State the types of TIG Welding Torches.
Ans: The types are:
- ➔ Air-cooled torch
- ➔ Water-cooled torch
Q38: What is a TIG Unit?
Ans: A TIG unit is a complete welding system that includes power supply, torch, gas supply, and control system used for TIG welding.
Q39: What is Argon Gas?
Ans: Argon gas is an inert gas used in welding to protect the weld area from atmospheric contamination.
Q40: State the functions of Argon Gas.
Ans: The functions are:
- ➔ Protects the weld from air
- ➔ Prevents oxidation
- ➔ Stabilizes the arc
- ➔ Improves weld quality
Q41: What is a Shielding Gas Cylinder?
Ans: A shielding gas cylinder is a container used to store and supply protective gases like argon during welding.
Q42: What is Current Adjustment in TIG Welding?
Ans: Current adjustment in TIG welding is the process of setting the required current level to control heat and weld quality.
Q43: What is a GMAW?
Ans: GMAW (Gas Metal Arc Welding) is a welding process in which a consumable wire electrode and shielding gas are used to join metals.
It is also known as MIG welding.
Q44: State the components of GMAW Equipment.
Ans: The components are:
- ➔ Power source
- ➔ Wire feeder
- ➔ Welding gun
- ➔ Gas cylinder
- ➔ Control unit
Q45: What is a Welding Gun?
Ans: A welding gun is a device used in MIG welding to feed the electrode wire and direct the shielding gas to the weld area.
Q46: State the parts of a Welding Gun.
Ans: The parts are:
- ➔ Nozzle
- ➔ Contact tip
- ➔ Trigger
- ➔ Gas diffuser
- ➔ Cable
Q47: Name some Shielding gases.
Ans: Some shielding gases are:
- ➔ Argon
- ➔ Helium
- ➔ Carbon dioxide (CO2)
- ➔ Oxygen
Q48: Name the gas used for welding Mild Steel.
Ans: The gas commonly used for welding mild steel is:
Q49: What is Arc of MIG Welding?
Ans: The arc of MIG welding is an electric arc formed between the wire electrode and the workpiece, which produces heat to melt the metal.
Q50: What is Current Adjustment in MIG Welding?
Ans: Current adjustment in MIG welding is the setting of current level to control penetration, heat input, and weld quality.
Q51: State any four advantages of MIG Welding.
Ans: The advantages are:
- ➔ High welding speed
- ➔ Easy to operate
- ➔ Less spatter
- ➔ Good weld quality
Q52: State the disadvantages of MIG Welding.
Ans: The disadvantages are:
- ➔ Equipment is costly
- ➔ Not suitable for outdoor use (wind affects gas)
- ➔ Requires shielding gas
- ➔ Less portable
