研究了桥梁建筑用耐候钢在含Cl-环境下表面锈层的腐蚀行为。结果表明,耐候钢组织由粒状贝氏体、针状铁素体以及准多边形铁素体组成。材料中的微量合金元素Mn可以降低腐蚀后期晶粒尺寸,促进α-FeOOH和γ-FeOOH相形成,提高材料表面锈层致密度。而Cu主要富集在锈层孔洞和缝隙处,能够改善表面锈层质量,提高耐候钢的抗腐蚀性。 The corrosion behavior of weathering steel for bridge construction on rust layer in Cl-containing environment was studied. The results show that the weathering steel consists of granular bainite, acicular ferrite and quasi-polygonal ferrite. The microalloying element Mn in the material can reduce the grain size at the late stage of corrosion, promote the formation of α-FeOOH and γ-FeOOH phase, and increase the density of rust layer on the surface of the material. However, Cu is mainly concentrated in voids and cracks in the rust layer, which can improve the quality of the surface rust layer and improve the corrosion resistance of the weathering steel.