输电铁塔耐候钢在不同大气环境下的腐蚀行为

为推广耐候钢在输电杆塔中的应用，试制了输电铁塔用高强高韧型耐候钢。该型钢具有优异的力学性能：屈服强度高达510 MPa，抗拉强度达568 MPa，总伸长率大于27.5%，-40 ℃低温冲击功在89~176 J。采用SEM、XRD、EIS等手段综合评价了输电铁塔耐候钢在4个不同地方的耐腐蚀性能，研究了耐候钢在不同大气环境中的腐蚀行为及其耐蚀机理。结果表明：输电铁塔耐候钢锈层电阻随暴晒时间增加而逐渐增大，锈层腐蚀产物主要由α-FeOOH、γ-FeOOH、Fe3O4及一些非晶态腐蚀产物组成。河北曹妃甸地区耐候钢保护性锈层最稳定，输电铁塔耐候钢适合在河北曹妃甸、北京良乡和福建永泰地区使用，暂不适合在福建平潭地区使用。

Corrosion Behavior of Transmission Tower Weathering Steel under Different Atmospheric Conditions

For application of weathering steel in transmission tower, a type of high strength and high toughness weathering steel is successfully developed for transmission towers, which has excellent mechanical properties with a yield strength of up to 510 MPa, a tensile strength of 568 MPa, a total elongation of greater than 27.5%, and the impact energy of 89 J~176 J under the low temperature of minus 40 ℃. The corrosion resistance of transmission tower weathering steel is evaluated comprehensively in four different atmospheric conditions by using SEM, XRD, EIS and other means. The corrosion behavior and mechanism of weathering steel in different atmospheric environments are studied. The results show that the rust resistance of transmission tower weathering steel increases gradually with increasing exposure duration. The rust corrosion product is mainly composed of α-FeOOH, γ-FeOOH, Fe3O4 and some amorphous corrosion products. Comparing with other weathering steels, the weathering steel used in Hebei Caofeidian region is most stable in protective rust layer. The transmission tower weathering steel is suitable for using in Hebei Caofeidian, Beijing Liangxiang and Fujian Yongtai regions, but temporarily not for Fujian Pingtan area.