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1.
钼酸锂的制备及其对碳钢在溴化锂溶液中的缓蚀作用   总被引:1,自引:0,他引:1  
 采用中和法制备钼酸锂,通过静态挂片法研究了钼酸锂对碳钢在溴化锂溶液中缓蚀的作用,并通过极化曲线探讨其缓蚀作用的机理,用扫描电镜观察形成的表面膜形态,用X-射线衍射法对形成的表面膜层结构进行分析.实验表明钼酸锂对碳钢在溴化锂溶液中有一定的缓蚀作用,其中添加0.020 mol/L钼酸锂和0.20 mol/L 氢氧化锂显著抑制溴化锂溶液对碳钢的腐蚀,其可能是在碳钢表面形成一层三氧化二铁、钼酸锂和三氧化钼组成的钝化镆,阻滞阳极反应从而起到缓蚀作用.  相似文献   

2.
新型巯基三唑化合物对HCl介质中碳钢的缓蚀作用研究   总被引:3,自引:2,他引:3  
合成了两种新型巯基三唑化合物,分别采用腐蚀失重法、动电位扫描极化曲线和交流阻抗法研究了其在1.0mol/L HCl介质中对Q235钢的缓蚀作用,分析了缓蚀作用机理.结果表明:对碳钢在1.0mol/L HCl溶液中,合成的巯基三唑化合物是性能优异的缓蚀剂.  相似文献   

3.
双咪唑啉季铵盐的合成与缓蚀性能研究   总被引:10,自引:1,他引:10  
利用两步法合成了双咪唑啉季铵盐化合物,通过失重法研究了该化合物在1g/L HCl 0.16g/L H2S 1g/L NaCl溶液和10%的盐酸溶液中对碳钢的缓蚀性能,讨论了用量、温度、时间对缓蚀性能的影响,并通过极化曲线和扫描电镜研究了该化合物的缓蚀机理。结果表明,该化合物在HCl-H2S-NaCl-H2O和10%的盐酸腐蚀环境中对碳钢具有良好的缓蚀作用,是一种以阳极控制为主的混合型缓蚀剂。  相似文献   

4.
TiO2复合膜在0.5mol/L硫酸溶液中的耐蚀机理探讨   总被引:1,自引:0,他引:1  
宋来洲  林万舟 《腐蚀与防护》2003,24(10):441-444
采用化学镀/溶胶—凝胶复合法在碳钢表面制备TiO2复合膜,采用环境扫描电镜(ESEM)表征了复合膜的表观形貌和断面形态。用恒电位阶跃、电化学阻抗谱等方法研究TiO2复合膜在0.5mol/L硫酸溶液中的耐蚀性能,结果表明,形成复合膜后,碳钢表面的耐蚀性能优良。结合环境扫描电镜的元素面扫描结果,初步探讨了TiO2复合膜在0.5mol/L硫酸溶液中的耐蚀机理。  相似文献   

5.
三聚氰胺对碳钢在 HCl 介质中的缓蚀作用   总被引:1,自引:1,他引:0  
目的了解在HCl介质中,三聚氰胺对碳钢的缓蚀作用和缓蚀机理。方法在1 mol/L HCl溶液中添加不同浓度的三聚氰胺,测试碳钢在溶液中的动电位极化曲线和电化学阻抗谱,获得电化学参数和缓蚀效率。再结合量子化学计算结果,分析其缓蚀机理。结果针对碳钢在1 mol/L HCl溶液中的腐蚀,三聚氰胺是一种混合抑制型缓蚀剂,随其浓度的增加,缓蚀效率增大。三聚氰胺通过分子中Mulliken电荷相对较负的氮原子吸附在碳钢表面起到缓蚀作用,吸附过程为自发过程,以物理吸附为主,且符合Langmuir吸附等温方程。结论在HCl介质中,三聚氰胺对碳钢具有一定的缓蚀作用。  相似文献   

6.
HCl介质中双季铵盐对碳钢的缓蚀作用   总被引:7,自引:0,他引:7  
合成了一种双季铵盐缓蚀剂(BQA),分别用腐蚀失重 法和电化学测试法研究了其在HCl介质中对碳钢的缓蚀作用及缓蚀机理.结果显示,对碳钢 在1.0 mol/L HCl溶液中BQA是一种性能优异的缓蚀剂.  相似文献   

7.
天然海水中高效缓蚀剂对碳钢缓蚀作用的研究   总被引:8,自引:0,他引:8  
以锌盐、葡萄糖酸盐为主要缓蚀成分复配的适用于天然海水中碳钢的高效缓蚀剂,用失重法测定其缓蚀效率,并用电化学方法分析其缓蚀作用机理.结果表明:未预膜时缓蚀剂的临界浓度是280mg/L.此时对碳钢的缓蚀率为93.8%,试样表面光亮如初,没有局部腐蚀;预膜后缓蚀剂的临界浓度降为210mg/L,此时对碳钢的缓蚀率为93.1%.通过极化曲线分析可知该缓蚀剂是一种抑制阳极过程为主的混合型缓蚀剂.据交流阻抗谱图分析得到该缓蚀剂成膜反应分3个阶段:反应初期,缓蚀剂在电极表面初步吸附;反应中期,至浸泡48h时第一层缓蚀膜形成;反应后期,缓蚀膜向多层发展.  相似文献   

8.
盐酸溶液中羧甲基壳聚糖对碳钢的缓蚀吸附性能研究   总被引:2,自引:0,他引:2  
用失重法研究了1 mol/L盐酸溶液中羧甲基壳聚糖(Carboxymenthylchitosan(CM-chitosan))对碳钢的缓蚀作用.结果表明,CM-chitosan对碳钢在盐酸介质中的腐蚀具有良好的缓蚀作用,随着浓度的增加缓蚀效率增大.在200 mg/L的浓度下达到最高.用电化学阻抗法测定了碳钢在盐酸溶液中的零电荷电位,确立了CM-chitosan 的吸附模型.303K~343K内CM-chitosan在碳钢表面的吸附遵循Langmuir规律,并获得吸附过程ΔGo、ΔHo和ΔSo等重要热力学参数.  相似文献   

9.
采用动电位极化曲线和电化学阻抗谱研究了焦磷酸钠在模拟混凝土孔溶液中对钢筋的保护作用。焦磷酸钠的加入导致混凝土中钢筋的腐蚀电位正移,主要通过抑制钢筋的阳极电化学过程起缓蚀作用。其缓蚀效果随焦磷酸钠浓度的增加而增大,在含0.04mol/L Cl-的混凝土模拟液中,当焦磷酸钠浓度为0.03mol/L时,其缓蚀效率可达到97....  相似文献   

10.
IAA 在硫酸溶液中对碳钢的缓蚀性能研究   总被引:1,自引:0,他引:1  
目的研究吲哚-3-乙酸(IAA)在H2SO4(0.1 mol/L)溶液中对碳钢(Q235)的缓蚀性能,降低碳钢生产过程对环境的影响。方法采用动电位极化曲线测试、交流阻抗实验、失重实验和扫描电镜实验分析缓蚀剂的缓蚀性能及作用机理。结果 IAA的缓蚀效率随着缓蚀剂浓度的增加而逐渐增大,当IAA浓度增加到4×10-3mol/L时,缓蚀效率最高达到88.85%。温度升高,缓蚀效率降低,说明IAA不宜于高温下使用。IAA是一种混合型缓蚀剂,对阴极反应和阳极反应均有抑制作用,且在缓蚀剂分子吸附过程中,吸附在碳钢表面的水分子和缓蚀剂分子发生竞争吸附作用,能有效阻止H+的穿越,从而抑制腐蚀H+的放电。IAA在碳钢表面的吸附遵循Langmuir吸附等温模型,该吸附自发进行且是物理吸附和化学吸附共同作用。缓蚀剂通过抑制腐蚀反应的活性点,提高活化能垒,防止碳钢溶解腐蚀。IAA在碳钢表面形成保护膜,减轻了腐蚀。结论 IAA是一种以抑制阳极反应为主的混合型缓蚀剂,在0.1 mol/L H2SO4溶液中能够对Q235碳钢起到优异的保护作用。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

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.
An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.  相似文献   

18.
A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.  相似文献   

19.
On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.  相似文献   

20.
吴玉梅  熊晓云  靳蓉  孙敬民  杨林  罗晓星 《金属学报》2005,10(10):1100-1103
目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。  相似文献   

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