Welding Processes & Techniques Flashcards
7 cards from real WCL 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 Processes & Techniques flashcards as text
What is 'spray transfer' in GMAW, and what shielding gas is required for it?
Answer: A stream of fine droplets axially transferred across the arc, requiring at least 80% argon in the shielding gas
Spray transfer produces a smooth stream of fine droplets across the arc and requires a shielding gas with at least 80% argon to achieve the transition current threshold.
Which document governs qualification of welding procedures and welders for most structural steel work in the US?
Answer: AWS D1.1 Structural Welding Code — Steel
AWS D1.1 is the primary structural welding code for steel in the US, governing WPS qualification, welder qualification, and inspection requirements.
What does 'PWHT' stand for, and what is its primary purpose in welding?
Answer: Post-Weld Heat Treatment; relieves residual stresses and tempers the HAZ after welding
PWHT (Post-Weld Heat Treatment) involves controlled heating and cooling of the completed weld to relieve residual stresses and improve HAZ toughness.
In SMAW, what does the last two digits of an electrode classification (e.g., E7018) indicate?
Answer: The type of coating and usable welding current
The last two digits of an SMAW electrode classification indicate the type of flux coating and the compatible welding current (AC, DC+, DC-).
What is the purpose of a 'root opening' (root gap) in a groove weld joint?
Answer: To allow access for the root pass to achieve complete joint penetration
The root opening provides space at the bottom of the groove so the welder can achieve complete joint penetration with the root pass.
Which discontinuity is most likely to occur when welding dissimilar metals with significantly different thermal expansion coefficients?
Answer: Cracking due to thermal stress mismatch
When dissimilar metals with different expansion rates are joined, differential thermal movement during heating and cooling creates stresses that can lead to cracking.
What is the function of the 'contactor' in a GMAW welding gun circuit?
Answer: It energizes the wire electrode only when the trigger is pulled, preventing accidental contact with live wire
The contactor is a safety switch that energizes the wire electrode only when the trigger is depressed, preventing the wire from being live when not welding.