知识与财富的链接
目的 研究3种典型耐候钢在江津大气环境中暴晒1 a的初期腐蚀行为。方法 采用户外大气挂片、腐蚀质量损失、SEM、XRD、电化学等方法,研究Q355NH、Q460FRW、Q690的腐蚀速率、锈层形貌、锈层物相和锈层电阻,并与Q345碳钢进行对比。结果 耐候钢和碳钢在大气暴晒初期的腐蚀规律是一致的,Q355NH、Q460FRW、Q690和Q345碳钢的腐蚀速率分别为0.050 9、0.053 6、0.047 8、0.055 mm/a,Q690的腐蚀速率最小,约为碳钢的87%。耐候钢和碳钢的锈层都主要由α-FeOOH、γ-FeOOH和Fe2O3组成,耐候钢的锈层更致密,裂纹更少。Q355NH、Q460FRW、Q690的锈层电阻值分别为821.3、1 005、1 080?·cm2,碳钢为101.68?·cm2,耐候钢的锈层电阻值约为碳钢的10倍。Cr和Cu元素在耐候钢的锈层中富集明显。结论 耐候钢的腐蚀速率低于碳钢,3种耐候钢的耐蚀性顺序为Q690>Q355NH>Q460FRW。Cr和Cu元素在...
The work aims to study the initial corrosion behavior of 3 weathering steels exposed in Jiangjin atmospheric environment for 1 a. The corrosion rate, and the morphology, phase and resistance of the rust layer of Q355NH, Q460FRW, Q690 and carbon steel Q345 were investigated and compared by outdoor coupon, corrosion mass loss, SEM, XRD, electrochemistry and other methods. The results showed that corrosion law of weathering steel and carbon steel at the initial stage was consistent. The corrosion rate of Q355NH, Q460FRW, Q690 and Q345 was 0.050 9, 0.053 6, 0.047 8 and 0.055 mm/a respectively. The corrosion rate of Q690 was the lowest, which was about 87% of carbon steel. The rust layer of weathering steel and carbon steel were mainly composed of α-FeOOH, γ-FeOOH and Fe2O3. There were fewer cracks in the rust layer of weathering steel, which was more dense than carbon steel. The rust layer resistance of Q355NH, Q460FRW, Q690 and Q345 was 821.3, 100 5, 108 0 and 101.68 Ω.cm2. The rust layer resistance of weathering steel was about 10 times that of carbon steel. Chromium and copper elements were obviously aggregated in the rust layer of weathering steel. The corrosion rate of weathering steel is lower than that of carbon steel, and the order of corrosion resistance of three weathering steels is Q690>Q355NH>Q460FRW. Enrichment of chromium and copper elements in the rust layer promote the rust layer of weathering steel to be more dense, and have greater resistance and better protection.
