Common delivery conditions?
Hot-rolled (AR): Low cost, suitable for ≤16mm, room temperature and low pressure.
Normalized (N): Uniform grains, good toughness, suitable for thick plates/low temperature.
Controlled rolling (TMCP): Balances strength and toughness, commonly used for medium and thick plates.
Is flaw detection required?
Important structures require flaw detection:
UT (Ultrasonic Testing): Commonly used, Class I/II/III.
MT (Magnetic Particle Testing): Surface/near-surface defects. Pressure vessels often require 100% UT II grade.
What are the Z-direction properties?
Thickness-direction resistance to lamellar tearing, for welded joints in thick plates (>40mm):
Z15: Reduction of area ≥15%
Z25: ≥25%
Z35: ≥35%.
What temperatures below -100°C can it be used?
Q345D: -20℃ (commonly used low temperature)
Q345E: -40℃ (extremely cold regions).
How is the weldability?
Good, low carbon equivalent (Ceq≈0.42%), conventional welding rods (E50 series) are sufficient, but thick plates require preheating to prevent cracking.