Welding Process Principles Flashcards
6 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 6 Welding Process Principles flashcards as text
In Shielded Metal Arc Welding (SMAW), what is the primary function of the electrode's flux coating during the welding process?
Answer: To form a protective gaseous shield and a slag layer over the weld pool.
The flux coating on an SMAW electrode decomposes in the heat of the arc, producing a gaseous shield that displaces atmospheric oxygen and nitrogen, and also forms a layer of slag. Both the gas and slag protect the molten weld pool from contamination, ensuring the integrity of the weld.
A welding procedure requires a process with a non-consumable electrode and a separate filler metal to be added manually. Which of the following welding processes should be selected?
Answer: Gas Tungsten Arc Welding (GTAW)
Gas Tungsten Arc Welding (GTAW), also known as TIG, is unique among these options because it uses a non-consumable tungsten electrode to create the arc. Filler metal, when required, is added separately to the weld pool. The other processes listed all use consumable electrodes.
When using Direct Current Electrode Negative (DCEN) polarity, also known as straight polarity, what is the primary effect on the weld characteristics?
Answer: A higher deposition rate and less penetration.
In DCEN, electrons flow from the electrode (negative) to the workpiece (positive). This concentrates more of the arc's heat (approximately two-thirds) on the electrode, causing it to melt faster, which results in a higher deposition rate. Less heat is directed into the base material, leading to shallower penetration.
A construction project requires welding thick structural steel plates in an outdoor, windy environment. Which variation of the Flux-Cored Arc Welding (FCAW) process would be most suitable for this application?
Answer: Self-shielded (FCAW-S)
Self-shielded Flux-Cored Arc Welding (FCAW-S) is the most suitable choice. The flux inside the tubular electrode generates its own protective shielding gas, making it resistant to wind and eliminating the need for an external shielding gas cylinder, which would be impractical and ineffective in windy outdoor conditions.
Which of the following is a defining characteristic of the Submerged Arc Welding (SAW) process?
Answer: A blanket of granular flux covers the arc and weld pool.
The Submerged Arc Welding (SAW) process is characterized by an arc that is 'submerged' under a blanket of granular flux. This flux layer protects the molten weld from the atmosphere, prevents spatter, and insulates the weld, allowing for very high deposition rates and deep penetration. The arc is not visible during the operation.
Gas Metal Arc Welding (GMAW) is most commonly operated with which type of power source characteristic?
Answer: Constant voltage
GMAW typically uses a constant voltage (CV) power source. This characteristic creates a self-regulating or self-correcting arc length. If the arc length shortens, the current increases to burn back the wire faster. If the arc length increases, the current decreases, slowing the wire burn-off rate, thus maintaining a stable arc.