Q355D Fire Protection?
A: Same as ordinary steel structures: fire-retardant coating, fireproof board, cladding, meeting fire resistance limits of 1.5-3 hours.
Q355D Weather Resistance?
A: 20-30% higher than Q235; heavy-duty corrosion protection is still required in coastal/industrial areas.
Key Points for Weld Corrosion Protection?
A: Grind excess weld slag, remove rust to Sa2.5 grade, touch up paint before topcoat, no missed areas.
Q355D Service Life?
A: With proper corrosion protection, 50-100 years for building structures.
Q355D Acceptance Inspection Items?
A: Quality certificate (composition, mechanical properties, -20℃ impact)
Appearance, dimensions, surface defects
Mechanical property retest (yield strength, tensile strength, -20℃ impact)
Thick plates/critical components: UT flaw detection