管) tube 钢管 steel pipe 铸铁管 cast iron pipe 衬里管 lined pipe 复合管 clad pipe 碳钢管 carbon steel pipe 合金钢管 alloy steel pipe 不锈钢 stainless steel pipe 奥氏体不锈钢管 austenitic stainless steel pipe 铁合金钢管 ferritic alloy steel pipe 轧制钢管 wrought-steel pipe 锻铁管 wrought-iron pipe 无缝钢管 seamless (SMLS) steel pipe 焊接钢管 welded steel pipe 电阻焊钢管 electric-resistance welded steel pipe 电熔（弧）焊钢板卷管 electric-fusion (a