耐候钢表面锈层稳定化研究现状

Research Status on Surface Rust Layer Stabilization of Weathering Steel

耐候钢表面形成的致密保护性锈层使其具有良好的抗大气腐蚀性能,经锈层稳定化处理后再使用是耐候钢最具有现实意义的使用方式。耐候钢表面锈层的组织结构、形成机理及过程、保护机理的研究,对于锈层稳定化处理技术和处理剂的开发具有基础性作用。首先,全面综述了近年来耐候钢表面锈层的研究进展,耐候钢经过基体铁的溶解、锈的还原、锈的再氧化等过程,形成了以Fe_3O_4、α-Fe OOH、无定形的羟基氧化物(FeO_x(OH),x=0~1)为主的连续致密内锈层,以β-FeOOH、γ-FeOOH为主的疏松多孔外锈层,内外锈层构成了耐候钢表面锈层。相较于普碳钢,耐候钢表面锈层具有连续致密、阳极钝化、离子选择性等特性,使得耐候钢具有良好的抗大气腐蚀性能。然后,归纳了目前国内外主要的锈层稳定化处理方法及其优缺点,主要有氧化物涂膜处理、氧化铁-磷酸盐系处理、喷丸+高温氧化处理等方法,但存在应用范围狭窄、有污染等问题。最后,基于合金元素在耐候钢中的作用提出了锈层稳定化处理剂组分的设计思路,并从应用范围、绿色环保、缩短稳定化周期等提出了耐候钢表面锈层稳定化处理剂研究的进一步建议。

The weathering steel has good resistance to atmospheric corrosion due to its compact and protective rust layer.It is the most practical way to reuse weathering steel after the rust-stabilizing treatment.The research on the structure,formation mechanism and process,and protection mechanism of the surface rust layer on weathering steel plays a fundamental role in the development of rust layer stabilization treatment and rust stabilizer.Firstly,the research progress of surface rust layer on weathering steel in recent years is reviewed.The weathering steel forms the compact inner rust layer with Fe3O4,α-FeOOH and amorphous oxyhydroxide(FeOx(OH),x=0~1)and the loose outer rust layer withβ-FeOOH andγ-FeOOH through the dissolution of the matrix iron,the reduction of rust,and the reoxidation of rust.The inner rust layer and the outer rust layer forms the surface rust layer on the weathering steel.Compared with carbon steel,the surface rust layer of weathering steel has the characteristics including continuous compactness,anode passivation and ion selectivity which provided the weathering steel with good resistance to atmospheric corrosion.Next,the rust layer stabilization treatment method at home and abroad and their advantages and disadvantages are summarized,mainly including oxide coating treatment,iron oxide-phosphate treatment,shot peening+high temperature oxidation treatment and so on,but there are still a few problems,including the narrow application range,pollution,etc.Finally,the design idea of the rust stabilizer composition based on the role of alloying elements in weathering steel is proposed,and the further suggestion for the study on the rust stabilizer of weathering steel is proposed from the scope of application,environmental protection,and shortening of the stabilization period.