AWS Metallurgy & Materials Flashcards
7 cards from real AWS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 AWS Metallurgy & Materials flashcards as text
What is the primary cause of hydrogen-induced cracking (HIC) in high-strength steel welds?
Answer: Diffusible hydrogen trapped in the heat-affected zone under tensile stress
HIC occurs when diffusible hydrogen becomes trapped in the HAZ or weld metal under tensile stress, causing delayed cracking.
Which crystal structure is associated with austenitic stainless steel at room temperature?
Answer: Face-centered cubic (FCC)
Austenitic stainless steels retain an FCC crystal structure at room temperature due to sufficient austenite-stabilizing elements like nickel.
In welding metallurgy, what does the term 'eutectic' refer to?
Answer: A specific alloy composition that melts and solidifies at a single temperature
A eutectic composition is the specific alloy mixture that has the lowest melting point and transforms directly between liquid and solid at a constant temperature.
What is the effect of increasing carbon content on the hardenability of steel?
Answer: Increases hardenability and lowers the Ms temperature
Higher carbon content increases hardenability (the ability to form martensite) while simultaneously lowering the martensite start (Ms) temperature.
Which type of corrosion is most commonly associated with sensitized austenitic stainless steel welds?
Answer: Intergranular corrosion
Sensitization causes chromium carbide precipitation at grain boundaries, depleting chromium and making the steel susceptible to intergranular corrosion.
What is the purpose of normalizing a steel weld joint after welding?
Answer: To refine the grain structure and relieve residual stresses by heating above the upper critical temperature and air cooling
Normalizing refines coarse grain structures in the HAZ and weld metal by austenitizing and allowing controlled air cooling.
Which alloying element is most effective at improving the creep resistance of steel used in high-temperature welded applications?
Answer: Molybdenum
Molybdenum significantly improves creep resistance by forming stable carbides and strengthening grain boundaries at elevated temperatures.