2015 HL section B Question 5 (Welding) Flashcards
Outline two methods to prevent perosity occuring in welds
clean materials eliminate drafts and air eliminate moisture proper use of anti-spatter sprays/gels make sure gas tank isnt empty
compare the electrode used in MIG welding and the electrode used in TIG welding
MIG welding: The electrode is consumable
TIG Welding: The electrode is made from tungsten. It is non-consumable
Describe the carbruising flame flame used in oxy-acetylene welding
has an excess of acetylene. used for aluminium alloys
Suggest a suitable method to protect against each of the following when welding:
Electric shock
intense light from welding
Welding fumes
Electric shock: Make sure you’re using correct connectors and that there are no water spillages
Welding fumes: You could use an exhaust fan
Intense light from welding: You could use welding curtains or use a face mask
The Kart shown has a welded mild steel frame
Select a suitable welding process for joining the frame and outline one reason for your selection.
MIG welding because the MIG welding torch can move easily
Describe, in detail, the key principles of MIG welding
Consumable bare wire electrode is fed continuously into weld pool.
Argon creates a protective shield around the weld pool
Feed rate and flow of gas are set by the operator. This allows the operator to guide the torch along the weld once the arc is generated between the electrode and the work.
It does not produce a slag on the weld
Can be used on heavy plate and sheet metals
Using the following guidelines compare resistance seam welding and resistance spot welding: Electrode shape Principle of operation Weld joint Application
Electrode shape: In resistance seam welding the electrode is a wheel. In resistance spot welding the electrodes are cylindrical
Principle of operation: In resistance spot welding the pieces are fused together by a nugget. In resistance seam welding a stream of electrical pulse passes through the rollers and the weld joint
