G-355NH耐候钢在不同区域气候环境中的大气腐蚀行为研究

Corrosion Behaviors of G-355NH Weathering Resistant Steel in Different Regional Climate

依据我国不同地域的气候特征,选择4种典型区域进行大气暴露试验,结合实验室周期浸润试验,开展不同气候条件下耐候钢的大气腐蚀规律研究。结果表明:区域性气候显著影响G-355NH低合金高强耐候钢的大气腐蚀行为,不同区域的G-355NH耐候钢腐蚀速率初期差异较大,温度和湿度对腐蚀速率影响显著,但当大气暴露12个月后各区域的腐蚀速率基本相同。不同区域腐蚀锈层达到一定深度趋于稳定,可有效保护基体,其中沿海高温环境下锈层厚度最大,其余区域厚度基本一致。不同区域条件下腐蚀层均包含α-FeOOH、γ-FeOOH、Fe3O4等产物,在南部沿海气候特征下还会产生一定的β-FeOOH。

According to the climatic characteristics of different regions in China,four kinds of typical regions were selected for atmospheric exposure test,and the atmospheric corrosion behaviors of weathering steel under different regional climatic conditions were studied combining with the alternate immersion atmospheric corrosion test.Results showed that the regional climate significantly affected the atmospheric corrosion behavior of G-355 NH low alloy high strength weathering resistant steel.The corrosion rates of G-355 NH steel in four regions were different at the beginning,and the temperature and humidity had significant effects on the corrosion rate.However,the corrosion rates of all areas were almost the same after atmospheric exposure for 12 months.Corrosion rust layers in different regions reached a certain depth and tended to be stable,which could effectively protect the substrate.Among them,the thickness of the rust layer in the coastal high temperature environment was the highest,and those of other regions were similar.Moreover,the corrosion layers in different regions containedα-Fe OOH,γ-Fe OOH and Fe3 O4.Under the southern coastal climate characteristics,a certain amount ofβ-Fe OOH was also produced.