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1.
海洋大气暴露3年的碳钢与耐候钢表面锈层分析   总被引:12,自引:1,他引:11  
通过对碳钢与耐候钢在海南,青岛两地挂片4年的大气腐蚀速率测定,对挂片表面锈层结构的观察,以及对锈层的组成和合金元素分布和分析,结果表明,在海洋大气环境下,耐候钢相对于碳钢未表现出明显的抗大气腐蚀性能,耐候钢表面锈层由比较致密的片状内锈层和疏松外锈层组成,内锈层主要是α-FeOOH,外锈层是α-FeOOH,γ-FeOOH,Fe3O4,碳钢表面锈层是由α-FeOOH,γ-FeOOH,Fe3O4组成的疏松单层结构,在青岛挂片表面锈层中发现了Cl元素的均匀分布,在海南挂片锈层中含有S,Cl,Cr等元素的局部富集,分析了S,Cl,Cr三者在锈层中的作用。  相似文献   

2.
陈惠玲  陈淑会  魏雨 《腐蚀与防护》2006,27(10):496-498
对碳钢在1.0mmol/L NaHSO3和1.0mmol/L Na2SO4溶液中分别进行周期浸润复合加速腐蚀试验,对其锈层进行红外光谱(IR)和扫描电镜(SEM)分析。各锈层物相组成相似,都含有-γFeOOH、-αFeOOH、Fe3O4和δ-FeOOH或FeSO4.7H2O。NaHSO3溶液中生成的锈层较疏松,颗粒较大,腐蚀速度较快;Na2SO4溶液中生成的锈层致密,腐蚀速度较低。并用Ferrihydrite对形成-γFeOOH和-αFeOOH的促进作用解释了试验结果。  相似文献   

3.
表面涂层改性处理的耐候钢挂片在2年的海洋性大气环境下暴晒,其腐蚀率是原耐候钢挂片腐蚀率的1/6。采用偏光、红外吸收、X射线衍射及EPAM对挂片锈层结构和组成进行了分析,发现碳钢、耐候钢表面锈层主要由γ-FeOOH、α-FeOOH及Fe3O4组成。α-FeOOH趋向在钢铁表面分布。改性涂层处理可以加速耐候钢表面生成保护性致密锈层,该锈层中富集有大量Cr,而碳钢挂片、裸露耐候钢挂片、涂层耐候钢挂片表面疏松锈层中没有Cr的富集。  相似文献   

4.
一种碳钢在模拟潮湿环境中腐蚀机理的探讨   总被引:1,自引:0,他引:1  
用IR、XRD和SEM分析对碳钢在湿热交替、室温下的干湿交替和吸附膜存在的室温干湿交替环境中的腐蚀实验产生的锈层进行了研究.确定了该锈层分为两层,外层是颗粒较小的γ-FeOOH,内层为Fe3O4及少量的α-FeOOH;提出FeOH+可吸附在Ferrihydrite(Fe5HO8·4H2O)表面促使其溶解并转化为γ-FeOOH和α-FeOOH;并解释了其原因.  相似文献   

5.
采用电化学阻抗方法,研究了在紫外光辐照下带锈层碳钢的腐蚀电化学行为,探究了紫外光所致的锈层光电催化效应及其对碳钢腐蚀的影响。结果表明,紫外光辐照能引发锈层光电催化反应,促使电极的腐蚀加速;锈层由γ-FeOOH外锈层和Fe2O3与Fe3O4内锈层组成,但它们在光电催化中的作用仍待研究。长期腐蚀过程的电化学阻抗谱图表明,带锈低碳钢电极的腐蚀比裸电极的大,随时间延长锈层逐步增厚引起光电催化效应强度增大,促进基体电极腐蚀程度增加;锈层积累42 d达到一定厚度时,随时间延长锈层促进基体电极腐蚀程度减缓,引起光电催化效应的强度会趋于一个稳定值。  相似文献   

6.
姜杉  王瑞珍  侯清宇  苏航 《热加工工艺》2012,41(18):72-75,79
采用人工海水对含有相同基本成分的C钢和添加了0.95%Cr元素的Cr钢进行120h的流动冲刷腐蚀试验.利用SEM和XRD等方法研究了Cr元素对普碳钢锈层的形貌、物相构成及相对含量的影响.结果表明,经冲刷腐蚀以后,含Cr钢的腐蚀质量损失小于C钢的.对两种钢的锈层分析表明,两种实验钢的锈层均出现分层现象,普碳钢外锈层疏松多孔,而含Cr钢的外锈层呈块状,致密性明显优于碳钢,内锈层亦是如此.两种钢的外锈层均由Fe3O4、α-FeOOH和γ-FeOOH等物相构成;C钢的内锈层由Fe3O4构成,Cr元素在含Cr钢锈层中的富集没有改变外锈层的物相类型,但内锈层则由Fe3O4转变为β-FeOOH.  相似文献   

7.
Q235碳钢在SO2气体中的初期腐蚀行为   总被引:1,自引:0,他引:1  
汪川  王振尧  柯伟 《金属学报》2008,44(6):729-734
通过SO2气体加速腐蚀实验,利用环境扫描电镜(XL30-FEG-ESEM)、能谱分析(EDAX)和Fourier红外光谱(FTIR)等分析技术,研究了碳钢Q235在湿热SO2气氛中的腐蚀行为和锈巢形成机制.结果表明:Q235在不同浓度SO2中腐蚀速率的变化趋势是不同的.浓度较高时,腐蚀速率随腐蚀时间延长而降低;浓度较低时,腐蚀速率随腐蚀时间延长缓慢增加.提高SO2浓度对锈层中含硫化合物的形成影响不大,但对锈层中氧化物或氢氧化物形成起到促进作用.实验条件下的腐蚀产物均含有FeSO4.7H2O,Fe2(SO4)3.9H2O,γ-FeOOH和无定形的δ-FeOOH,当SO2体积分数大于0.5%时,产物中还出现α-FeOOH.在0.05%SO2气氛中,Q235表面形成锈巢,锈巢内、外的各种元素含量差异很大.  相似文献   

8.
对Q450耐候钢在不同浓度NaCl溶液中模拟海洋大气环境进行了周期浸润试验.采用光学显微镜、扫描哇镜和X射线衍射仪对钢的腐蚀形貌、锈层截面和腐蚀产物进行了观察和分析.结果表明:随着NaCl浓度的提高,锈层变得疏松多孔;不同浓度NaCl溶液中主要腐蚀产物相同,均为γ-FeOOH及少量Fe3O4.  相似文献   

9.
周东辉  吴善宏  肖丽  王宏义  胡家元 《腐蚀与防护》2012,(12):1057-1059,1075
对碳钢在海水淡化一级反渗透产水中生成的锈层进行SEM、IR和XRD分析,并结合电化学测量,研究其腐蚀行为。结果表明,碳钢在一级反渗透产水中腐蚀过程受氧扩散控制,腐蚀产物包括γ-FeOOH、Fe3O4以及少量的α-FeOOH。锈层具有双层结构,外锈层很薄,主要成分为γ-FeOOH;内层占整个锈层比重很大,主要成分为Fe3O4。一级反渗透产水的弱酸性促使腐蚀产物γ-FeOOH迅速转化为Fe3O4,致使Fe3O4在金属表面大量堆积。由于Fe3O4层的导电性及不连续性,锈层不能阻碍阴极过程的进行,导致碳钢的腐蚀速度一直维持在高位。  相似文献   

10.
通过模拟工业大气环境的周期浸润实验室加速试验,研究耐候钢和碳钢的锈层腐蚀初期生长规律以及耐候钢锈层的耐腐蚀机理;对试验钢样进行了腐蚀失重分析,通过扫描电镜、X射线衍射等手段对锈层形貌和结构进行分析.结果发现,腐蚀初期耐候钢的锈层组织成分主要以α-FeOOH为主;碳钢的锈层组织成分主要以Fe2O3为主.α-FeOOH晶体枝晶尺寸纤细,锈层致密具有保护性;Fe2O3枝晶粗大,锈层疏松和多孔不具有保护性.  相似文献   

11.
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.  相似文献   

12.
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.  相似文献   

13.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

14.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

15.
韩磊 《腐蚀与防护》2015,36(1):84-90,94
综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。  相似文献   

16.
On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes' collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.  相似文献   

17.
The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.  相似文献   

18.
正I take great pleasure in congratulating CHINA FOUNDRY journal on its 10th anniversary.The CHINA FOUNDRY journal started ten years ago.Since its inaugural,China has seen exceptional growth in the Castings Sector and rapid development in Machinery Industry.The journal is becoming an important communication platform for experts  相似文献   

19.
正Harbin General Hydraulic Machinery Works Co.,Ltd.of Yilin Hydraulic Group is the most professional production base of large-scale metallurgy oil cylinder and oil machinery cylinder in the Northeast of China.The main products include metallurgy cylinder,swell-shrink cylinder,rotating injection device,lifting cylinder,main lifting jack,front lifting jack,engineering oil cyl-  相似文献   

20.
正Weihai HHH Mach.Elec.Group is the most technical company focusing on Power transmission and Hydra-controlling.HHH has the ability of developing and testing of complete sets of transmission system with relevant technical training.HHH provide efficient,excellent cost-effective power transmission system and intelligent electric fluid transmission and control system to OEM customers,who are  相似文献   

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