Material Properties & Inspection Standards Flashcards

What does the term 'anisotropy' mean in the context of boilermaker materials?

Answer: Properties that vary depending on direction of measurement

Anisotropy describes materials whose mechanical or physical properties differ based on the direction in which they are measured.

Which ASME standard governs the inspection and testing of pressure vessels?

Answer: ASME Section VIII

ASME Section VIII, Division 1 and 2 cover the design, fabrication, and inspection requirements for pressure vessels.

The hardness of a material is best defined as its resistance to:

Answer: Permanent surface indentation or scratching

Hardness is the material's resistance to localized plastic deformation, typically measured by indentation tests like Rockwell or Brinell.

In NDT of boiler materials, what condition does 'hydrogen embrittlement' describe?

Answer: Loss of ductility due to hydrogen absorption into the metal lattice

Hydrogen embrittlement occurs when atomic hydrogen diffuses into metal, reducing ductility and increasing susceptibility to cracking.

What is the purpose of a Charpy impact test on boiler plate material?

Answer: Evaluate notch toughness and ductile-to-brittle transition temperature

The Charpy V-notch test measures how much energy a material absorbs during fracture, indicating toughness and the temperature at which it transitions from ductile to brittle behavior.

Under ASME Section V, which article specifically covers radiographic examination?

Answer: Article 2

ASME Section V, Article 2 provides the requirements and procedures for radiographic examination of welds and materials.

Which type of steel is most commonly used in high-pressure boiler drum construction due to its combination of strength and weldability?

Answer: Low-alloy chromium-molybdenum steel

Chromium-molybdenum low-alloy steels offer excellent high-temperature strength, creep resistance, and good weldability, making them ideal for pressure vessel and boiler construction.