Q235B钢和含Cr耐候钢在文昌海洋大气暴露的锈层特征与耐蚀性

Rust Characteristics and Corrosion Resistance of Q235B steel and Cr-Bearing Weathering Steel in Wenchang Marine Atmosphere

采用腐蚀失重法、扫描电镜(SEM)、X射线衍射(XRD)、电子探针(EMPA)等技术研究了暴露在文昌海洋大气环境中的Q235B钢和3Cr钢的锈层特征和耐蚀性。结果表明:Q235B钢的腐蚀深度大于3Cr钢的;随暴露时间的延长,两种钢的腐蚀深度均增大,大气暴露时间为1.5a时,3Cr钢的相对腐蚀率明显下降。Q235B钢锈层存在较多裂纹,3Cr钢锈层致密,耐蚀性好。Q235B钢中Cl元素的富集降低了材料的耐蚀性,而3Cr钢中合金元素Cr富集在内锈层,Cl元素基本被阻滞在外锈层,提高了耐蚀性。

The rust layer characteristics and corrosion resistance of Q235 Bsteel and 3 Cr steel exposed to Wenchang marine atmosphere were studied by techniques such as corrosion weight loss method,scanning electron microscopy(SEM),X-ray diffraction(XRD)and electron micro probe(EMPA).The results show that the corrosion depth of Q235 Bsteel was greater than that of 3 Cr steel.The corrosion depth of both steels increased with the extension of exposure time.When the atmospheric exposure time was 1.5 a,the relative corrosion rate of 3 Cr steel decreased obviously.There were many cracks in the rust layer of Q235 Bsteel,and the rust layer of 3 Cr steel was dense and had good corrosion resistance.The enrichment of Cl in Q235 Bsteel reduced the corrosion resistance of the material,while the alloying element Cr in 3 Cr steel was enriched in the inner rust layer,and the Cl element was basically blocked in the outer rust layer,which improved the corrosion resistance of the material.