Welding Process Fundamentals 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 Fundamentals flashcards as text
What is the primary reason low-hydrogen electrodes must be stored in a rod oven?
Answer: To prevent moisture absorption, which can introduce hydrogen into the weld and cause cracking
Low-hydrogen electrode coatings readily absorb atmospheric moisture; hydrogen from this moisture dissolves in the weld pool and can cause hydrogen-induced (cold) cracking.
In electroslag welding (ESW), the primary heat source for melting is:
Answer: Resistance heating as current passes through the molten slag pool
ESW is not an arc process; once started, heat is generated by electrical resistance in the conductive molten slag pool through which the welding current passes.
What does 'arc blow' refer to in SMAW welding?
Answer: Deflection of the arc from its intended path due to magnetic forces in the workpiece
Arc blow occurs when stray magnetic fields in the base metal deflect the welding arc forward or backward, making it difficult to control the weld pool.
Which of the following base metal conditions most increases the risk of hydrogen-induced cracking (HIC)?
Answer: High carbon equivalent and high restraint
HIC risk increases with higher carbon equivalent (hardness), high hydrogen levels in the weld, and high restraint that prevents stress relief during cooling.
What is the purpose of a 'backing bar' in groove weld preparation?
Answer: To support the root pass and prevent burn-through, ensuring full penetration
A backing bar (backing strip) placed behind the root provides support for the first weld pass, allowing the welder to achieve full penetration without burning through.
In resistance spot welding (RSW), the weld nugget forms primarily due to:
Answer: Heat generated by electrical resistance at the faying surfaces as current passes through
In RSW, the highest resistance at the interface between the two workpieces generates concentrated heat that melts and fuses the metal into a nugget under electrode pressure.
What is meant by 'weld metal dilution' in a cladding or overlay application?
Answer: The proportion of base metal melted and mixed into the deposited weld metal
Dilution is the percentage of base metal mixed into the weld deposit; high dilution in overlay applications can degrade the chemical composition and corrosion resistance of the cladding layer.