ASTM A53覆盖无缝和焊接的黑色和热浸镀锌钢管。The pipes are frequently ordered as follows: Type Black, HDG Manufacturing SMLS, ERW Grade A B Chemical compositions C Mn P S ≤0.25% ≤0.95% ≤0.05% ≤0.045% Cu Ni Cr Mo ≤0.4% ≤0.4% ≤0.4% ≤0.15% V ≤0.08% C Mn P S ≤0.3% ≤1.2% ≤0.05% ≤0.045% Cu Ni Cr Mo ≤0.4% ≤0.4% ≤0.4% ≤0.15% V ≤0.08% Mechanical properties Yield strength Tensile strength ≥205 MPa ≥330 MPa屈服强度拉伸强度≥240MPa≥415MPa […]