AWS Filler Metals & Consumables 5 — Questions and Answers
Question 1: An E6010 electrode is preferred over E6013 for pipeline root passes primarily because it:
- Produces less spatter
- Penetrates through mill scale and contamination with a stiff arc (Correct answer)
- Has a higher deposition rate
- Requires lower amperage settings
Correct answer: Penetrates through mill scale and contamination with a stiff arc
E6010 uses a high-cellulose sodium coating that produces a forceful, digging arc capable of penetrating contaminated or tight-fit root gaps.
Question 2: What is the maximum allowable moisture content for low-hydrogen SMAW electrodes stored out of the original hermetically sealed container, per AWS D1.1?
- No moisture limit if oven-dried before use
- They must be used within 4 hours or returned to oven at 250–300°F (Correct answer)
- They may be stored indefinitely at room temperature
- Moisture is only a concern for cellulosic electrodes
Correct answer: They must be used within 4 hours or returned to oven at 250–300°F
AWS D1.1 requires low-hydrogen electrodes exposed to atmosphere to be used within 4 hours or reconditioned in a holding oven at 250–300°F (121–149°C).
Question 3: Which AWS A5 specification covers filler metals for brazing?
- AWS A5.8 (Correct answer)
- AWS A5.1
- AWS A5.18
- AWS A5.36
Correct answer: AWS A5.8
AWS A5.8 covers filler metals for brazing and braze welding, including silver, copper, and aluminum-based alloys.
Question 4: A flux-cored wire marked 'E71T-8' is intended for use with:
- 100% CO2 shielding gas
- 75% Ar / 25% CO2 shielding gas
- No external shielding gas (self-shielded) (Correct answer)
- Argon-helium blends only
Correct answer: No external shielding gas (self-shielded)
The 'T-8' designation in AWS A5.20 identifies a self-shielded flux-cored electrode that generates its own shielding from the flux core.
Question 5: When selecting a filler metal for welding 4130 chromoly steel in aerospace applications, the H4 diffusible hydrogen designator means the weld metal hydrogen content must not exceed:
- 4 mL per 100 g of weld metal (Correct answer)
- 8 mL per 100 g of weld metal
- 16 mL per 100 g of weld metal
- 2 mL per 100 g of weld metal
Correct answer: 4 mL per 100 g of weld metal
The H4 suffix per AWS A4.3 limits diffusible hydrogen to a maximum of 4 mL per 100 g of deposited weld metal.
Question 6: Which factor most directly determines whether a SAW flux is classified as 'fused' or 'bonded'?
- The basicity index of the flux
- The method of manufacture (melted vs. agglomerated with binder) (Correct answer)
- The particle mesh size distribution
- The ratio of fluoride to oxide content
Correct answer: The method of manufacture (melted vs. agglomerated with binder)
Fused fluxes are produced by melting and solidifying ingredients, while bonded (agglomerated) fluxes are made by mixing dry ingredients with a liquid binder and then baking.
Question 7: In GTAW of titanium, why must the filler rod be kept within the inert gas shielding zone during welding?
- To prevent the rod from oxidizing and introducing oxygen or nitrogen contamination into the weld pool (Correct answer)
- To maintain consistent arc length
- To prevent the rod from cooling too quickly
- To avoid arc blow caused by the magnetic field
Correct answer: To prevent the rod from oxidizing and introducing oxygen or nitrogen contamination into the weld pool
Titanium is highly reactive at elevated temperatures; exposing the hot filler rod to air causes oxide and nitride pickup that embrittles the weld.
AWS Filler Metals & Consumables 5
An E6010 electrode is preferred over E6013 for pipeline root passes primarily because it: