Q345B厚壁钢管无缝钢小口径厚壁钢管管的化学成分，Q345B无缝钢管现货 

Q345B无缝管C45#厚壁钢管:0.大口径厚壁钢管12-0.20S20#厚壁钢管i:0.20-0.60Mn:1.00-1.60P:≤0.040S:≤0.040Ni:≤0.30Cr:≤0.30Cu:≤0.20V:0.02-0.15Nb:0.015-0.06 Q345B无缝管C:0.12-0.20Si:0.20-0.60Mn:1.00-1.60P:≤0.040S:≤0.040Ni:≤0.30Cr:≤0.30Cu:≤0.20V:0.02-0.15Nb:0.015-0.06 

Q345B无缝钢管的化学成分，Q345B无缝钢管现货