Material Evaluation and Selection Flashcards
7 cards from real API 510 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Material Evaluation and Selection flashcards as text
What does the P-number system in ASME Section IX primarily classify base metals by?
Answer: Weldability characteristics including chemistry and mechanical properties
P-numbers group base metals with similar weldability so that a single welding procedure qualification covers all materials in the same group.
Which document provides primary material traceability for ASME pressure vessel components?
Answer: Mill test report (MTR) linked to the material heat number
The MTR ties chemical and mechanical properties to a specific heat number, enabling direct traceability of material used in pressure-containing parts.
Positive Material Identification (PMI) using X-ray fluorescence (XRF) is most effective for verifying which material property?
Answer: Alloy composition of chrome-moly or stainless steel components
XRF reliably detects alloying elements such as chromium, molybdenum, and nickel, but has limited sensitivity for carbon due to its low atomic number.
Carbon steel pressure vessel components are generally limited to service below which temperature to avoid graphitization damage?
Answer: 850°F (454°C)
Graphitization—the transformation of iron carbides into graphite nodules—becomes a practical concern in carbon steel above approximately 850°F (454°C) during extended service.
Where are the allowable stress values for ASME pressure vessel materials published?
Answer: ASME Section II Part D
ASME Section II Part D contains the stress tables, physical property data, and other material information referenced by all ASME fabrication codes.
The carbon equivalent (CE) formula is primarily used to evaluate a steel's susceptibility to what condition?
Answer: Hydrogen-induced cracking and cold cracking in the weld heat-affected zone
Higher carbon equivalents indicate greater hardenability, increasing the risk of hard, brittle HAZ microstructures susceptible to hydrogen cracking during or after welding.
When original material documentation is unavailable for an in-service pressure vessel, what is the recommended first step per API 510?
Answer: Perform PMI testing to identify alloy content and assign an appropriate material grade
PMI verifies the material's actual composition, allowing the inspector to assign a code-recognized material specification and calculate a defensible MAWP.