Mig

Question 1

Define four health and safety risks that occur from Mig welding

Answer 1

Arc Eye
Burns
metal Fume Fever
Electric shock
Heat exhaustion
Asphyxiation

Question 2

Define four precautions that must be taken to overcome the risks mentioned in question one

Answer 2

Head shields fitted with appropriate filter lens
Protective clothing
Extraction and ventilation
Protective Clothing
Electrical insulation, fuses

Question 3

Define two types of fire extinguisher that are suitable for use with electric arc welding

Answer 3

Co2
Dry Powder

Question 4

Define the colour of the fire extinguishers for use with electric arc welding

Answer 4

Co2 - red with black (high voltage)
Dry powder - red with blue (low voltage)

Question 5

Define three hazards associated with arc radiation

Answer 5

Visible light
Ultraviolet
Infrared

Question 6

Define three effects from visible light ultra violet light and infrared

Answer 6

Visible light - glare / eye strain
Ultra violet - arc eye / skin burn
Infrared- heat and skin burns

Question 7

Define three precautions that must be taken to reduce the hazards of visible light, ultra violet and infrared.

Answer 7

Visible light - use screens, non reflective painted walls

Ultra violet- head shields fitted with appropriate filter lens

Infrared- protective clothing

Question 8

Define two types of gaseous welding fumes associated with Mig welding.

Answer 8

Carbon monoxide
Ozone
Nitrous oxide
Nitrogen dioxide
Oxides of nitrogen

Question 9

Define two types of power source used for Mig welding

Answer 9

Transformer/rectifier
Generator
Inverter

Question 10

In a workshop situation define five components of a typical Mig welding torch.

Answer 10

Body/handle
Neck
Connections
Contractor/Switch
Nozzle
Gas Diffuser/Ports
Electrode wire
Contact tip

Question 11

Define three types of shielding gas mixtures commonly used in Mig welding of carbon steels

Answer 11

Argon / Carbon Dioxide
Carbon Dioxide
Argon / Oxygen / Carbon Dioxide
Argon / Oxygen
Argon / helium / Oxygen / Carbon Dioxide

Question 12

Define three precautionary methods used for controlling the effects of distortion during Mig welding

Answer 12

Welding in Sequence Eg Staggering Welds
Tacking
Pre Bending
Clamping
Pre heating
Joint design eg asymmetrical Joints
Welding parts back to back

Question 13

Define two types of induction control that are used in Mig welding

Answer 13

Fixed
Stepped
Variable

Question 14

Define the function of an induction control used in Mig welding

Answer 14

Reduces spatter during dip transfer

Slows down the rate of rise in current during dip transfers short circuit

provides Increased arc stabilisation during spray transfer

Question 15

Define the function of a gas pressure regulator and a flow metre

Answer 15

Adjustment and setting of gas pressure to welding system

Adjustment and setting of gas flow rate for welding

Question 16

Define the units that are used for a regulator and flow metre

Answer 16

PSI (pounds per square inch)
LPM (Litres per minute)

Question 17

Define the mode of metal transfer most suited for the following applications:
Thin sheet butt welds
10mm thick tee fillet in flat position
6mm lap fillet in the verticals position

Answer 17

Dip / short circuit transfer
Spray Transfer
Dip/Short circuit Tranfer

Question 18

Define three workshop based destructive tests that can be used on a butt welded joint

Answer 18

Bend ( root face or side)
Nick break (fracture)
Macro Examination
Cupping test

Question 19

From the diagram determine the type of joint, welding Position and type of weld that can be used to weld this joint

Answer 19

Lap
Verticals
Fillet

Question 20

Define the welding symbols
l l
📐
V

Answer 20

Square butt
Fillet
Single Vee butt