| 1. What does the "H" suffix denote in a grade like P11H? | It denotes a grade with specified requirements for elevated temperature tensile properties. |
| 2. What is "ditch corrosion" in duplex stainless steel welds? | A severe form of localized corrosion that occurs in the HAZ, often appearing as a deep groove, related to improper phase balance or precipitation of harmful intermetallics. |
| 3. What is the main advantage of seamless pipe over welded pipe for high-pressure applications? | The absence of a longitudinal weld, which is a potential continuous line of weakness, theoretically provides more uniform strength characteristics around the circumference. |
| 4. What is the primary cause of "solidification cracking" (hot cracking) in welds? | The presence of low-melting-point eutectics (e.g., iron sulfides) that solidify last at grain boundaries, creating liquid films that tear apart under thermal contraction stresses-8. |
| 5. What key property does the Charpy V-Notch (CVN) impact test measure? | It measures the absorbed energy required to fracture a notched specimen, indicating the material's notch toughness and resistance to brittle fracture at the test temperature-1. |
