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Chemical and Mechanical Properties of S355NL Steel Grade Spiral Steel Pipe
1、 Chemical composition
The chemical composition of S355NL spiral steel pipe complies with the European standard EN10025-3, with the following core elements and contents:
Carbon (C): 0.12%~0.20% (balance strength and weldability);
Silicon (Si): ≤ 0.50% (deoxidized and assisted strengthening);
Manganese (Mn): 1.00%~1.60% (core strengthening element, enhancing strength and toughness);
Phosphorus (P) and sulfur (S): both ≤ 0.030% (strictly limit impurities and reduce cold brittleness);
Alloy elements: containing trace amounts of niobium (Nb), vanadium (V), titanium (Ti), chromium (Cr ≤ 0.30%), nickel (Ni ≤ 0.30%), etc. (optimizing grain refinement and corrosion resistance).
2、 Mechanical performance
Basic performance (thickness related):
Yield strength (ReH):
Thickness ≤ 16mm: ≥ 355 MPa；
16~30mm：≥ 325 MPa；
≥30mm：≥ 295 MPa；
Tensile strength (Rm): 470~630 MPa;
Post fracture elongation (A5): ≥ 21%~24%.
Low temperature impact toughness:
-50 ℃ impact energy (V-notch): ≥ 27 J (ensuring stability in extremely low temperature environments);
Z-direction performance: Z15/Z25/Z35 grades can be selected (with a cross-sectional shrinkage rate of ≥ 15%/25%/35%, respectively, to prevent layer tearing).
Process performance:
Weldability: Supports arc welding, submerged arc welding, and gas shielded welding, with weld strength matching the base metal;
Processability: Easy to cut, bend, and shape, suitable for processing complex structures.
3、 Production and Standards
Execution standard: EN10025-3 (European standard normalized rolling fine grain steel);
Delivery status: normalizing or normalizing rolling (refining grain size and improving uniformity);
Testing requirements: Ultrasonic testing and X-ray re examination (weld quality).
4、 Application Fields
S355NL spiral steel pipe is suitable for high load and low temperature harsh environments:
Bridges and Buildings: Main beams of highways, railway bridges, and load-bearing structures of high-rise buildings;
Marine engineering: offshore platforms, ship decks, and low-temperature storage tanks;
Mechanical manufacturing: Heavy engineering machinery frames, mining equipment supports;
Energy facilities: Oil and gas pipelines and storage facilities in low-temperature areas (-50 ℃).
(Note: Specific parameters may be adjusted due to thickness, delivery status, and additional technical requirements.)
ADD：Chengnan Industrial Development Zone, Yanshan County, Hebei Province
Domestic phone number：0086-317-6689999
International call：0086-317-6165555
E-mail:9905791@qq.com
