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Q355B material steel pipe
Chemical composition and mechanical properties of Q355B spiral steel pipe material
1、 Chemical composition
Carbon (C): 0.14%~0.22%, or upper control limit ≤ 0.20%
Silicon (Si): ≤ 0.50%
Manganese (Mn): 1.20%~1.60%
Phosphorus (P): ≤ 0.035%
Sulfur (S): ≤ 0.035%
Alloy elements:
Chromium (Cr) ≤ 0.50%, nickel (Ni) ≤ 0.40%, molybdenum (Mo) ≤ 0.15%
Trace additions of vanadium (V), niobium (Nb), titanium (Ti), etc. to enhance performance
2、 Mechanical performance
Yield strength (Rp0.2): ≥ 355 MPa
Tensile strength (Rm): 470~760 MPa
Bending strength ratio (Rp0.2/Rm): ≤ 0.90 (controlling material plasticity)
Elongation (A): ≥ 21% (longitudinal specimen)
Impact toughness:
Impact energy at room temperature ≥ 34 J (longitudinal specimen)
Low temperature toughness (-20 ℃) requires additional testing according to the contract agreement
Manufacturing process:
Adopting spiral submerged arc welding (SAWH) process, the weld seam needs to pass non-destructive testing, TVRT radiographic testing, with a coverage rate of 100%
After welding is completed, a hydrostatic pressure test is required, and the test pressure shall be carried out according to the standard requirements
The residual height of the weld seam is ≤ 3.2mm, and there are no defects such as cracks or lack of fusion on the inner and outer surfaces.
3、 Other performance
Processing performance:
Suitable for cold bending, hot rolling, and controlled rolling and controlled cooling (TMCP) processes
After molding, the surface should be free of defects such as cracks and folds
Corrosion resistance:
The corrosion resistance of the substrate is average, and it needs to be combined with painting and 3PE anti-corrosion treatment to improve durability
Application scenarios:
Oil and gas transportation: medium and high pressure oil and natural gas pipelines
Building structure: bridges, load-bearing brackets for high-rise buildings
Mechanical manufacturing: construction machinery, vehicle structural components
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
