Welding Process Principles Flashcards
7 cards from real CWI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Welding Process Principles flashcards as text
What is the purpose of using a 'backing bar' in a groove weld?
Answer: To support the molten weld pool and ensure complete root fusion
A backing bar (or backing strip) is placed behind the root of the joint to support the molten pool, prevent burn-through, and help achieve complete joint penetration.
Which transfer mode in GMAW is generally associated with the highest heat input and is used for thick materials in the flat position?
Answer: Spray transfer
Spray transfer operates at high voltage and current, producing a steady stream of fine droplets with high heat input, making it suitable for thick materials in the flat or horizontal position.
In GTAW, what is the effect of using pure argon shielding gas on an aluminum weld?
Answer: It provides cathodic cleaning action that removes the oxide layer
When welding aluminum with GTAW using AC, the electrode-positive half-cycle provides a cathodic cleaning action that breaks up and removes the refractory aluminum oxide layer.
What is 'arc blow' in SMAW, and when is it most commonly encountered?
Answer: Magnetic deflection of the arc; most common with DC on ferromagnetic materials near the end of a joint
Arc blow is caused by unbalanced magnetic fields in the workpiece deflecting the arc, and it most frequently occurs with DC welding on ferromagnetic steel, particularly near joint ends or heavy fixturing.
Which welding process deposits filler metal using the resistance heating of a wire electrode fed into a molten slag pool?
Answer: Electroslag welding (ESW)
Electroslag welding uses the electrical resistance of a molten slag pool to generate heat, melting both the consumable electrode and base metal as the weld progresses vertically.
What is the function of the 'nozzle' in a GMAW gun?
Answer: Direct shielding gas around the weld zone
The nozzle directs and concentrates the shielding gas flow around the arc and weld pool to protect them from atmospheric contamination.
A CWI observes that a GMAW weld has excessive porosity. Which process variable is MOST likely the primary cause?
Answer: Inadequate shielding gas coverage
Porosity in GMAW is most commonly caused by inadequate shielding gas coverage, allowing atmospheric nitrogen and oxygen to enter the weld pool and become entrapped as gas pores.