: Remove only surface contaminants/loose scale without reacting with the substrate, so all core mechanical properties remain unchanged. Strict process control avoids substrate corrosion or strength loss.
SA2.5/SA3 sandblasting: The high-speed abrasive impact only acts on the outermost surface layer, not altering the substrate's internal structure or mechanical performance. It creates mild surface work hardening (improving wear resistance) and converts surface tensile stress to compressive stress, reducing stress corrosion cracking risk in salt spray environments.
: The thin inorganic accelerator layer (30-50μm) only forms a protective patina via surface chemical reaction, without penetrating the substrate or causing hydrogen embrittlement. It has zero impact on yield strength, toughness, weldability and secondary processability of Q355NHB.
: The thin organic sealer film (40-100μm) only covers the patina surface to block chloride ions, with no bonding to the steel substrate. It does not affect the steel's load-bearing capacity, thermal expansion/contraction or fatigue resistance within the service temperature range.
: Moderate grinding removes sharp burrs and surface oxide layers without reducing component cross-sectional area or load-bearing capacity. Rounding sharp edges eliminates stress concentration, which optimizes the fatigue resistance of components under dynamic loads (e.g., wind load) in coastal environments.
