Heat Input and Distortion Control Flashcards
7 cards from real Certified Welder practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Heat Input and Distortion Control flashcards as text
What is the correct formula for calculating heat input in welding?
Answer: (Amps × Volts × 60) / Travel Speed (in/min)
Heat input is calculated as (Amps × Volts × 60) / Travel Speed, expressed in joules per inch, representing total energy deposited per unit length.
What effect does increasing travel speed have on heat input when amperage and voltage remain constant?
Answer: Decreases heat input
Increasing travel speed reduces the time the arc dwells over a given area, depositing less energy per inch and thereby decreasing heat input.
Which type of distortion causes the ends of a welded plate to bow upward along its length?
Answer: Longitudinal bowing (camber)
Longitudinal bowing (camber) causes the ends of a welded plate to curve upward due to differential shrinkage along the long axis of the weld.
What is the primary purpose of preheating base metal before welding?
Answer: To reduce the risk of hydrogen-induced cracking by slowing the cooling rate
Preheating slows the cooling rate, allowing diffusible hydrogen to escape from the weld zone and reducing the risk of hydrogen-induced (cold) cracking.
What does interpass temperature refer to in a multi-pass weld?
Answer: The temperature of the weld bead before the next pass is deposited
Interpass temperature is the temperature of the previously deposited weld bead or base metal adjacent to the weld before the next pass is applied, and must be kept within specified limits.
High heat input in welding generally results in which of the following?
Answer: A larger heat affected zone and coarser grain structure
High heat input increases the size of the heat affected zone and promotes grain growth, producing a coarser microstructure that typically reduces notch toughness.
When voltage and travel speed are held constant in GMAW, which parameter most directly controls heat input?
Answer: Wire feed speed (which controls amperage)
In GMAW, wire feed speed directly controls amperage; since heat input = (Amps × Volts × 60) / Travel Speed, changing amperage is the primary lever when the other two variables are fixed.