Z. Zhang
,
C. Cai
,
F.H. Cao
,
Z.N. Gao
,
J.Q. Zhang
,
C.N. Cao
金属学报(英文版)
The corrosion behavior of pure aluminum in neutral 3.0% (mass fraction) sodium chloride (NaCl) solution has been studied using electrochemical impedance spectroscopy (EIS) measurement in conjunction with the scanning electron microscopy (SEM) technique. EIS information on the evolution of pitting corrosion over a period of 15 days has been obtained and analyzed with equivalent circuit technique. The results shown that, during the ensemble constant immersion time, two time constants involved, the high frequency one originated from the protective layer on the corroding surface while the low frequency one from the diffusion process or the corrosion reaction and so on. And there existed a period for oxide film to growth and thickening prior to the commencement of the attacking of chloride ions to the substrate. Meanwhile, good relationship between EIS and the material corrosion type / severity has been obtained, which has been interpreted according to the characteristics of corrosion process such as auto acceleration of pitting corrosion and the protection of local anodic reaction to the area around them.
关键词:
pure aluminum
,
null
,
null
Q. Qu
,
C.W. Yan
,
L. Li
,
L. Zhang
,
G.H. Liu
,
C.N. Cao
金属学报(英文版)
Influence of NH4Cl on the initial atmospheric corrosion of zinc was investigated via
quartz crystal microbalance (QCM) in laboratory at 80%RH and 25℃. The results
show that NH4Cl can accelerate the initial corrosion of zinc. Mass gain increase with
the exposure time, but mass gain in the later doesn't change obviously due to the
formation of the insoluble simonkolleite on zinc surface in the presence of NH4Cl.
Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) was
used to characterize the corrosion products. Zn5Cl2(OH)8·H2O, (NH4)2ZnCl4 and
ZnO are the corrosion products on zinc. Brief discussion on the mechanisms of atmospheric corrosion of zinc in the presence of NH4Cl was introduced.
关键词:
atmospheric corrosion
,
null
,
null
刘建辉
,
陶绍平
,
聂作禄
,
王景彬
耐火材料
doi:10.3969/j.issn.1001-1935.2002.04.012
采用抗水化处理后的镁钙砂为原料,研制了MgO-CaO-C砖,并对使用MGO-CaO-C砖过程中钢液中夹杂数量和氧含量的变化情况进行了分析.结果表明:MgO-CaO-C砖在钢包包壁非渣线部位使用,能减少钢中氧含量和夹杂物数量,降低夹杂粒径,改变夹杂粒度分布,提高钢水质量.
关键词:
MgO-CaO-C砖
,
钢包
,
内衬
,
夹杂物
,
氧含量
何龙
,
王玺堂
,
王周福
,
杨承燕
,
许欢
,
秦梦黎
人工晶体学报
以SiC为抗氧化剂添加至MgO-CaO-C耐火材料中,研究了SiC对提高MgO-CaO-C耐火材料抗氧化性能的作用及抗氧化机理.通过TG-DSC、XRD、显气孔率测定以及近似计算氧化层面积等进行分析和鉴定.结果表明:加入SiC后MgO-CaO-C耐火材料的抗氧化性能得到显著提高,结构更加致密.材料中SiC大约在1210℃开始与氧气反应,反应后生成的SiO2继续和MgO反应生成镁橄榄石,从而填充气孔形成致密氧化层阻止碳的进一步氧化.
关键词:
MgO-CaO-C耐火材料
,
抗氧化
,
SiC
,
镁橄榄石
牛建平
,
孙晓峰
,
金涛
,
于洋
,
杨克努
,
管恒荣
,
胡壮麒
材料工程
doi:10.3969/j.issn.1001-4381.2000.12.002
研究了使用CaO坩埚在VIM法精炼Ni基高温合金过程中N的变化规律及加Al对脱N 的影响,初步分析了脱N的影响因素及机理.
关键词:
CaO坩埚
,
Ni基高温合金
,
精炼
,
脱N
潘波
,
尹国祥
,
王健东
,
高心魁
,
孙加林
耐火材料
doi:10.3969/j.issn.1001-1935.2009.01.009
分别以30%(w)的烧结镁钙砂A、烧结镁钙砂B、电熔镁钙砂3种镁钙砂原料与62%(w)的电熔镁砂、8%(w)的鳞片石墨制备了3种CaO质量分数均为6%的MgO-CaO-C砖.利用回转抗渣法对比了3种MgO-CaO-C砖抗CaO-SiO2渣的侵蚀性能,并对残砖进行了SEM分析.结果表明:(1)Mgo-CaO-C砖抗CaO-SiO2渣侵蚀的能力与镁钙砂的致密度成正比,电熔镁钙砂抗渣侵蚀性能及挂渣性能皆优于烧结镁钙砂.(2)镁钙砂的CaO的分布影响Mgo-CaO-C砖的抗渣性能:电熔镁钙砂的CaO形成连续相而将MgO与渣隔离开来,更有利于抗CaO-SiO2渣侵蚀;烧结镁钙砂的CaO分布不均匀,会导致Mgo-CaO砂的不均匀熔损,进而加速渣对其侵蚀.
关键词:
镁钙砂
,
抗渣性
,
致密度
,
CaO分布
尹国祥
,
潘波
,
高心魁
,
王健东
,
余占国
耐火材料
doi:10.3969/j.issn.1001-1935.2010.05.009
以电熔镁钙砂(粒度为5～3、3～1和≤1 mm)为骨料,电熔镁砂(≤0.074 mm)为基质,分别加入3%(w)的大鳞片石墨(≤0.149 mm)、细鳞片石墨(≤0.044 mm)、微孔化石墨(≤0.074 mm)制备了3种超低碳MgO-CaO-C砖试样,并对比了其高温强度、抗氧化性、抗热震性和抗渣侵蚀性.结果表明:(1)石墨种类对超低碳MgO-CaO-C砖的物理性能影响不大.(2) 大鳞片石墨制备的超低碳MgO-CaO-C砖的抗氧化性和抗渣侵蚀性较好,而微孔化石墨制备的试样抗热震性最好;考虑到整体性能,碳源以1.5%(w)大鳞片石墨与1.5%(w)微孔化石墨的复合形式加入最佳.
关键词:
MgO-CaO-C砖
,
石墨
,
抗热震性
,
抗渣侵蚀性能
杨红
,
尹国祥
,
孙加林
耐火材料
doi:10.3969/j.issn.1001-1935.2008.03.016
以锆酸钙和石墨为主材料,添加熔融石英、硅灰石、锆英石制成新型ZrO2-CaO-C-SiO2质浸入式水口,将其在鞍钢某连铸机上正常浇铸铝镇静钢6炉后,取钢液面下的水口残样,借助EDAX、SEM等手段对其显微结构进行了分析.结果表明:新型ZrO2-CaO-C-SiO2质浸入式水口在浇铸高铝镇静钢时抗Al2O3附着性能好,从钢液反应层到试样内部依次为致密层、过渡层、原砖层,其中致密层的性质决定着浸入式水口的使用性能.
关键词:
锆酸钙
,
氧化铝附着
,
致密层
,
浸入式水口
,
铝镇静钢
