AWS Shielded Metal Arc Welding (SMAW) 5 — Questions and Answers
Question 1: What type of current is required for an E6010 electrode to operate correctly?
- AC only
- DCEN (DC electrode negative) only
- DCEP (DC electrode positive) only (Correct answer)
- Either AC or DCEP
Correct answer: DCEP (DC electrode positive) only
E6010 electrodes require DCEP (DC electrode positive, also called reverse polarity) to maintain a stable arc and achieve proper penetration.
Question 2: A welder is experiencing excessive spatter while using E7018 electrodes. Which adjustment would most likely resolve this issue?
- Increase amperage significantly
- Decrease amperage slightly (Correct answer)
- Switch to DCEN polarity
- Increase arc length
Correct answer: Decrease amperage slightly
Excessive spatter with E7018 is often caused by amperage that is too high; decreasing amperage slightly typically reduces spatter to acceptable levels.
Question 3: What is 'porosity' in a weld, and what is its most common cause in SMAW?
- Surface roughness caused by high travel speed; corrected by slowing down
- Gas pockets trapped in the solidified weld metal; often caused by contamination or moisture (Correct answer)
- Cracks along the weld centerline; caused by high sulfur content
- Incomplete fusion; caused by insufficient amperage
Correct answer: Gas pockets trapped in the solidified weld metal; often caused by contamination or moisture
Porosity consists of gas pockets (voids) trapped in the solidified weld metal, most commonly caused by contamination, moisture on the electrode or base metal, or too-long arc length.
Question 4: According to AWS standards, what does the 'E' in an electrode classification such as E7018 stand for?
- Electrode efficiency
- Arc energy
- Arc electrode
- Electric arc welding electrode (Correct answer)
Correct answer: Electric arc welding electrode
The 'E' in AWS electrode classifications stands for 'Electric arc welding electrode,' distinguishing it from other welding rods.
Question 5: When should preheat be applied to base metal before SMAW?
- Only when welding in freezing temperatures
- When welding high-carbon or alloy steels to reduce the risk of hydrogen cracking (Correct answer)
- Only when welding stainless steel
- Preheat is never required for SMAW
Correct answer: When welding high-carbon or alloy steels to reduce the risk of hydrogen cracking
Preheat slows the cooling rate, allowing hydrogen to escape and reducing the risk of hydrogen-induced cracking, particularly in high-carbon and alloy steels.
Question 6: What is the correct action if an E7018 electrode has been left out of the oven for more than 4 hours?
- Use them immediately to avoid further moisture absorption
- Discard them — they cannot be reconditioned
- Recondition them by re-baking at the manufacturer's recommended temperature and time (Correct answer)
- Store them at room temperature and use within 24 hours
Correct answer: Recondition them by re-baking at the manufacturer's recommended temperature and time
Low-hydrogen electrodes exposed to atmosphere beyond the allowable time limit can be reconditioned (re-baked) per AWS D1.1 and manufacturer guidelines to restore their low-hydrogen properties.
Question 7: What is 'stringer bead' technique in SMAW, and when is it preferred?
- A bead deposited with a wide weave motion; preferred for flat position only
- A narrow bead deposited with little or no side-to-side motion; preferred when low heat input is required (Correct answer)
- A bead deposited in reverse direction; preferred for thick materials
- A bead deposited in multiple passes simultaneously; preferred for production welding
Correct answer: A narrow bead deposited with little or no side-to-side motion; preferred when low heat input is required
A stringer bead uses little or no lateral movement, resulting in lower heat input, which is preferred for materials sensitive to heat distortion or when welding thin sections.
AWS Shielded Metal Arc Welding (SMAW) 5
What type of current is required for an E6010 electrode to operate correctly?