Q345 High-Temperature Strength Changes?
A: Strength decreases slightly at ≤350℃; decreases significantly at ≥400℃; becomes unstable at ≥600℃, requiring fire protection.
Q345 Corrosion Protection Measures for Banks?
A: Indoor: Epoxy/Polyurethane anti-corrosion paint; Outdoor/Humid: Hot-dip galvanizing + sealing paint; Buried: Heavy-duty anti-corrosion + cathodic protection.
Q345 Corrosion Protection Key Points for Vaults/Underground Facilities?
A: High humidity/corrosive environments use Q345C/D/E + heavy-duty anti-corrosion; galvanized/epoxy steel reinforcement is used inside concrete to prevent chloride ion corrosion.
Q345 Service Life?
A: Normal environment + good corrosion protection: 50–100 years; Harsh environment: 20–30 years (requires regular maintenance).
How much more expensive is Q345 than Q235?
A: The unit price is 10-20% higher, but the usage is reduced by 15-30%, so the overall cost is close to or lower, and the safety redundancy is higher.