薄液膜下航天器异种材料电偶腐蚀兼容性

针对文昌航天发射中心航天器产品的腐蚀评价需求,提出一种基于薄液膜三电极系统的航天器异种材料电偶腐蚀兼容性评价方法.设计了一套薄液膜三电极系统,在控温控湿的薄液膜条件下对5种航天器材料进行了电偶腐蚀试验.结果表明:由于欧姆电阻和阴阳极金属极化率的影响,薄液膜比水溶液全浸更适宜作为航天器异种材料电偶腐蚀兼容性评价的试验条件,电偶电流密度与试验条件明显相关.航天器异种材料电偶腐蚀兼容性评价应使用控温控湿的薄液膜三电极系统进行,并以电偶电流密度作为电偶腐蚀兼容性的评价判据.     

铸态Al-4%Zn合金的电偶腐蚀研究

采用自由测试法测定了铝合金分别与Q235钢、镀锌铁片和铜片三种不同材料组成的电偶在3.5%NaCl水溶液中的电偶电流、腐蚀电位和腐蚀速度.研究了加速铝合金电偶腐蚀的因素.结果表明,铝合金在含有氯离子的溶液中腐蚀较严重;并且偶合材料、阴阳极面积比对铝合金的电偶腐蚀有重要影响.     

不锈钢管凝汽器管板电偶腐蚀的研究

研究了不锈钢管凝汽器碳钢管板电偶腐蚀的严重程度、影响因素和防护措施,并与黄铜管-碳钢腐蚀电偶对进行了比较.结果表明：凝汽器黄铜管改成不锈钢管后,碳钢管板电偶腐蚀依然存在,但腐蚀程度明显低于黄铜管.此外,面积比对电偶腐蚀影响较大,可采用阴极保护、阴极保护加管板涂层联合保护及缓蚀剂等减小电偶腐蚀.     

表面阳极化对7050铝合金电偶腐蚀的影响

为了研究表面阳极化对7050铝合金电偶腐蚀性能的影响,通过测定7050铝合金与TC18钛合金组成电偶对的腐蚀电流的方法,评定了7050铝合金与TC18钛合金接触的电偶腐蚀敏感性.结果表明：7050铝合金与TC18钛合金接触时会产生严重的电偶腐蚀,电偶腐蚀的敏感性为D级;而阳极化的7050铝合金与TC18钛合金接触产生的电偶腐蚀敏感性级别降低为B级,提高了表面抗腐蚀性能.     

电冰箱换热器以铝代铜腐蚀特性的实验研究

通过T2纯铜和1060纯铝在R22制冷剂和5%的HCl、H2SO4、NaOH、NaCl溶液中的纯腐蚀和电偶腐蚀实验,比较了铜和铝的腐蚀特性.结果表明铜在各介质中腐蚀速度都相当低,表现出良好的耐蚀性,而铝在这5种介质中的纯腐蚀速度差别巨大.铝在制冷剂R22中表现出了与铜相似的耐蚀性,腐蚀速度只有0.041 mm·a-1.在NaCl中的腐蚀速度也较低,为0.063 mm·a-1.但在HCl和NaOH中腐蚀极严重.铜-铝电偶腐蚀结果表明铝被加速腐蚀,而铜的腐蚀过程受到抑制.铝可以代替铜作为冰箱换热器材料,但应进行必要的表面涂覆处理.     

海水凝汽器海优管与AL-6XN管板的电偶腐蚀

用电化学和失重法研究了不同介质条件下超级铁素体不锈钢管海优和超级奥氏体不锈钢AL-6XN之间的电偶腐蚀性能.实验结果表明:若采用AL-6XN作凝汽器管板, 海优作冷却管, 一般不会发生电偶腐蚀.     

Ho对AZ91镁合金腐蚀行为的影响

采用重力铸造方法制备了3种Ho改性AZ91镁合金。通过腐蚀实验对改性合金的自腐蚀和电偶腐蚀行为进行了研究。结果表明,随着Ho含量的增加,改性合金的自腐蚀性能和电偶腐蚀性能逐步提高,当Ho的质量分数为1.10%和2.16%时,合金的耐蚀性能较佳。此外,阴极的特性对改性合金的腐蚀性能有明显影响,4种材料的阴极作用由弱到强依次为:铝硅合金,纯铝,45#钢和球墨铸铁。Ho通过抑制β相的阴极作用,增加自腐蚀电位,提高了合金的腐蚀性能。     

BMAT对盐酸酸洗中不锈钢—碳钢电偶腐蚀的抑制作用

运用失重法及电偶电流的测量评定了ＢＭＡＴ对３１６Ｌ／碳钢组成的电偶对在５％（质量分数）ＨＣｌ中的缓蚀性能,结果表明,ＢＭＡＴ能很好地抑制此电偶对的腐蚀;极化曲线的测量表明：ＢＭＡＴ既能抑制发生在电偶对中碳钢阳极溶解反应Ｆｅ→Ｆｅ＾２＋＋２ｅ,又能抑制 阴极析氢反应２Ｈ＋２ｅ→Ｈ２。     

碳纤维增强铝合金层板的腐蚀损伤演变与力学性能

纤维金属层板是一种综合性能优异的轻量化材料,已经成功地应用于航空航天领域.其中,使用碳纤维增强的纤维金属层板比采用玻璃纤维或芳纶纤维的层板具有更好的力学性能.然而,碳纤维与金属的结合容易引起电偶腐蚀,极大地限制了其应用.本文采用电化学方法、光学显微镜和扫描电子显微镜等分析了碳纤维增强铝合金层板在腐蚀环境中的腐蚀演变,探...     

比较法定标温差电偶实验不确定度评定

温差电偶是测量温度的有效工具，在实践中广泛应用，但温差电偶在使用前须进行定标，确定温差电动势与温度的对应关系，即测定温差电偶常数α，然后才能用来测量温度．用实验测定温差电偶常口数，称为温差电偶的定标．文章介绍了比较法定标温差电偶实验的原理及过程，对比较法定标温差电偶实验的不确定度进行了评定，给出了实验测量结果的不确定度．     

Galvanic Corrosion of Magnesium Alloy and Aluminum Alloy by Kelvin Probe

Galvanic corrosion on samples of AZ91D magnesium alloy coupled with 2A12 aluminum alloy during neutral salt spray test was investigated.The variations of the surface potential were measured using scanning kelvin probe(SKP).The results showed that galvanic effect on the corrosion of AZ91D magnesium alloy is closely related to the potential difference between the anodic and cathodic materials.In the initial period,corrosion only occurred in a narrow area at the coupling interface because of the limited distance galvanic current.Then,the corrosion rate of 2A12 aluminum alloy was accelerated due to its poor stability in strong alkali environment,which was attributed to the strong alkalization caused by the corrosion of AZ91D magnesium alloy.With the increase of the potential of 2A12 aluminum alloy as a result of the continuous covering of corrosion products,the potential difference between the two materials was enlarged,which enhanced the galvanic corrosion.     

Effect of Stress and Galvanic Factors on the Corrosion Behave of Aluminum Alloy

The interaction between stress and galvanic during the corrosion process of 5050 aluminum alloys was studied and the evolution of mechanics properties was indicated. Electrochemical impedance technique and scanning electron microscopy were used to analyze the surface electrochemical states and the corrosion morphology. At the same time, corrosion kinetics and thermodynamic theory were used to analyze the influencing mechanism of the stress factor and the galvanic factor. The results show that both of galvanic factor and tensile stress factor can increase the corrosion potential of aluminum alloys and result in the corrosion resistance decrease. With decreasing corrosion resistance, the mechanical properties of aluminum alloys decrease. These phenomena are attributed to two reasons: One is that aluminum alloys may under the condition of anodic polarization after coupled with 40 Cr Ni Mo A steel, so the corrosion can be promoted; The other is that with increasing stress, the electrochemical potential of 5050 aluminum alloys decreases and the potential difference between two materials increases, so the corrosion becomes serious. Compared to the stress factor, the galvanic factor is significant.     

7475铝合金与TC18钛合金接触腐蚀研究

为了研究7475铝合金接触腐蚀性能,测定了7475铝合金和TC18钛合金组成的电偶对的电偶电流,利用扫描电镜和光学显微镜对腐蚀表面形貌和深度进行分析,研究了7475铝合金和TC18钛合金在使用中接触时产生电偶腐蚀的敏感性.结果表明:7475铝合金不同表面处理状态与TC18接触时,7475铝合金与TC18接触腐蚀严重,电偶腐蚀的敏感性为C级.7475阳极化与TC18阳极化处理后接触腐蚀敏感性降低,电偶腐蚀的敏感性为A级,对7475阳极化后进行涂漆可进一步降低电偶腐蚀电流.     

Effects of electroplated coatings on corrosion behavior of Ti-1023/30CrMnSiA galvanic couple

Galvanic corrosion behavior of Ti-1023 titanium alloy coupled 30CrMnSiA steel was investigated in 3.5% NaCl solution. Particular attention was given to the effect of three different electroplated coatings on corrosion behavior of the galvanic couple. Galvanic corrosion test was conducted on Ti-1023 titanium alloy which coupled Ni-electroplated 30CrMnSiA, Zn-electroplated 30CrMnSiA, Cd-electroplated 30CrMnSiA and bare 30CrMnSiA, respectively. Corrosion properties including open circuit potential （Eoc）, galvanic corrosion potential （Eg）, and galvanic corrosion current （lg） were monitored. Corrosion morphology was observed by optical microscope （OM） and corrosion mechanism was analyzed and discussed. The results show that the three electroplated coatings improve the corrosion resistance of the anode in different magnitudes. Ni-electroplated 30CrMnSiA and Cd-electroplated 30CrMnSiA coatings are found to be least susceptible to galvanic corrosion when coupled Ti-1023 titanium alloy. Zn-electroplated 30CrMnSiA is moderately susceptible to galvanic corrosion. But the bare 30CrMnSiA is highly susceptible to galvanic corrosion in corrosive environment.     

镁合金与Q235钢在罐底水溶液下的电偶腐蚀行为

利用浸泡实验、电化学测试和微观形貌观测研究大榭油库罐底水模拟溶液下镁合金与Q235钢体系的电偶腐蚀行为,对比研究不同Sc/Sa (阴/阳极面积比)对镁合金/Q235钢电偶腐蚀的影响,探明Sc/Sa与腐蚀速率的关系,并拟合成曲线和表达式.结果表明,当电极阴极面积不变时,随着Sc/Sa的增加,镁合金阳极的腐蚀速率大幅度增加...     

海域管护舰艇需求的数学模型

舰艇武器装备是海上移动执法平台，是海上执法部队完成使命任务的基本保证。执法舰艇总体规模需求分析非常复杂。提出多艇随机巡逻、多艇之间配合以及舰艇和舰载直升机配合3种执法舰艇数量需求数学模型，并针对北部湾海域管护任务进行计算。     

Galvanic corrosion behavior of die cast AZ91D magnesium alloy in chloride solution

The galvanic corrosion behavior of die cast AZ91D magnesium alloy coupled with H62 brass, 316L stainless steel, A3steel and LY12 aluminum alloy of different areas in 3.5% NaC1 solution was studied. The free corrosion potentials, galvanic potentials and currents of these galvanic couples were measured. The galvanic effects were determined by the mass loss and regression method using three points. The results show that: (1) In these four kinds of couples AZ91D acts as the anode, whose galvanic corrosion behavior is mainly controlled by the cathodic polarization; (2) The free corrosion potentials of these four kinds of couples change a liffle with time and cathodic/anodic area ratio (CAAR); (3) The galvanic potential of AZ91D/LY12 moves positively with the increase of time and CAAR; (4) The galvanic currents increase with CAAR, but there is difference in the current change between different couples; (5) The anodic dissolution rate of the magnesium alloy increases by 2-3 orders after being coupled with these four kinds of metals and the galvanic effects of these couples have such a relation as γH62＞γ316LS.S＞γLY12 ＞γA3.