共查询到19条相似文献,搜索用时 62 毫秒
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8090Al-Li合金晶间腐蚀与剥落腐蚀性能研究 总被引:4,自引:0,他引:4
本文研究了8090Al—Li合金的点蚀、晶间腐蚀和剥落腐蚀性能,探讨了热处理制度对耐腐蚀性能的影响。结果表明:Al-2.79Li-1.3Cu-0.7Mg-0.12Zr合金自然时效态抗晶间腐蚀和剥落腐蚀性能最佳,峰时效状态耐腐蚀性能最差,欠时效比过时效略好。显微组织观察表明合金的耐蚀性能与显微组织密切相关,峰时效条件下,粗大T_2相连续分布于晶界上,它的电位比基体电位低因此晶界构成阳极通道,从而使合金耐蚀性能恶化。 相似文献
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8090Al-Li合金晶间腐蚀与剥落腐蚀性能研究SCIEI 总被引:2,自引:0,他引:2
本文研究了8090Al—Li合金的点蚀、晶间腐蚀和剥落腐蚀性能,探讨了热处理制度对耐腐蚀性能的影响。结果表明:Al-2.79Li-1.3Cu-0.7Mg-0.12Zr合金自然时效态抗晶间腐蚀和剥落腐蚀性能最佳,峰时效状态耐腐蚀性能最差,欠时效比过时效略好。显微组织观察表明合金的耐蚀性能与显微组织密切相关,峰时效条件下,粗大T_2相连续分布于晶界上,它的电位比基体电位低因此晶界构成阳极通道,从而使合金耐蚀性能恶化。 相似文献
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通过化学浸泡试验、动电位极化曲线的测量并结合扫描电镜(SEM)对经特殊热处理的690合金(690TT)点蚀形貌的观察,研究探讨了两种国产690TT合金在室温下的点蚀性能;并根据ASTM G48A与ASTM G61两种标准对690TT合金抗点蚀性能评估进行了比较。结果表明:两种国产690TT合金中,合金B的抗点蚀性能显著优于合金A的。ASTM G48A对690TT合金进行点蚀试验的最佳试验参数为50℃/3h,所得相应数据结果可靠;由于缝隙腐蚀等原因使ASTM G61对690TT合金管的点蚀电位测量稳定性不佳,可重复性较差。 相似文献
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Ni-Cr-Mo-Cu合金的氧化动力学研究 总被引:3,自引:0,他引:3
运用静态等温氧化法研究了Ni-Cr-Mo-Cu镍基耐蚀合金在600、800和1000℃下的氧化特性,采用X射线衍射、扫描电子显微镜对氧化层进行了相结构和形貌的分析。结果表明:该合金的高温氧化动力学曲线近似呈立方抛物线规律,10h以后氧化过程主要受扩散控制,合金表面形成致密的氧化物薄膜,氧化物类型主要是Cr2O3和NiO、NiCr2O4。实验得到Ni-Cr-Mo-Cu耐蚀合金高温氧化速率常数为1.296×10-8exp(-Ea/RT),其表观活化能(Ea)为200.25kJ/mol,位于Cr2O3氧化层的活化能和NiO氧化层的活化能之间。 相似文献
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研究了可伐合金在3.5%NaCl溶液中恒电流下的电位-时间关系。结果表明,恒电流下的峰值电位是点蚀诱发电位;准确态阶段是点蚀稳定发展阶段。点蚀诱发电位与外加阳极电流密度的对数成线性关系,准确态值通常(除盐膜溶解控制外)依赖于外加阳极电流密度并随时间缓慢减小。 相似文献
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NiTi合金是目前应用最广的形状记忆合金,在富Ni的NiTi合金中,NiTi的机械性能受相变温度的影响,且与基体中Ni的含量有关。热处理对NiTi耐点蚀行为的影响没有被系统地研究过,香港科技大学应用物理系研究组对此进行了研究。从2mm厚的NiTi板(含Ni50.8%)切取13mm×13mm的样品,用砂纸 相似文献
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镍基高温合金M17和M38G的电化学腐蚀行为研究 总被引:1,自引:1,他引:1
采用电化学方法、扫描电镜、能谱分析等技术,研究了常温下镍基高温合金M17和M38G在NaCl溶液和含S2O2-3的NaCl溶液中的腐蚀行为.结果表明,在含质量分数为3.5% NaCl的溶液中,M17和M38G均会遭受严重的点腐蚀;向NaCl溶液(NaCl质量分数为3.5%)添加Na2S2O3(Na2S2O3质量分数为1.5%)后,由于溶液中的S2O2-3在试样表面活性点与Cl-竞争吸附并与H 结合,使两种合金的点蚀均受到抑制;M38G中存在微量的Nb、Ta、Mo等元素使得M38G合金在NaCl溶液中的耐腐蚀性能明显优于M17合金. 相似文献
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用电化学极化方法研究了Ti50Ni50,Ti50Ni42Cu8及317L合金在不同pH值的15NaCl水溶液中的耐蚀性。恒电位阳极极化曲线表明:Cu的加入明显提高了TiNi合金的再钝化电位;但对点蚀电位的影响较复杂,在pH1 ̄5时TiNiCu高于TiNi合金,在pH=6 ̄10时TiNiCu则低于TiNi合金,pH值增大至11 ̄13时,两者又趋于接近。实验中还发现,与317L相比,TiNi合金的点蚀 相似文献
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ZA27合金晶间腐蚀电子理论研究 总被引:3,自引:0,他引:3
为从本质上了解杂质与稀土元素Y对锌铝合金晶间腐蚀的影响,探索抑制合金晶间腐蚀的有效途径,依据晶界的大角度重位点阵理论建立了含稀土、杂质及η相颗粒的α相大角度晶界原子集团模型,采用递归法计算了α相晶界间的电荷转移,由此讨论了杂质(Pb、Sn、Cd)及稀土元素Y对Zn、Al电极电位的影响。结果表明:杂质Pb、Sn、Cd增大原子间的电荷转移量,提高Zn、Al电极电位差,加速合金的腐蚀,稀土元素减小原子间的电荷转移量,降低Zn、Al电极电位差,具有抑制晶间腐蚀的作用。 相似文献
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研究了不含Zn及0.72%Zn微合金化的Al-3.7Cu-1.15Li-0.5Mg合金T6态时效(150及175℃)不同时间后的晶间腐蚀行为,建立了其腐蚀-时效进程状态图。结果表明,Zn微合金化铝锂合金晶间腐蚀敏感性略低于不含Zn微合金化的铝锂合金。随时效进程的发展,铝锂合金腐蚀类型变化规律为:孔蚀或局部晶间腐蚀(时效早期),全面晶间腐蚀(欠时效阶段),局部晶间腐蚀(近峰时效阶段),孔蚀(过时效阶段)。晶间腐蚀深度随时效时间延长呈先增加而后降低的规律。时效时间延长,一方面晶界析出相逐渐粗化并且呈不连续分布,另一方面晶内T1相及θ相析出,晶内电位降低,晶界及晶内电位差减小,从而导致上述腐蚀类型的变化。 相似文献
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The effects of shot peening(SP) and plasma electrolytic oxidation(PEO) on the intergranular corrosion behavior of the novel high strength aluminum alloy 7A85(AA 7A85) were investigated by electrochemical polarization and electrochemical impedance tests.The intergranular corrosion mechanism of SP,PEO and PEO combined with sealingtreated AA 7A85 was studied by the metallographic analysis,residual stress testing,X-ray diffractometer analysis and scanning electron microscopy.The results show that AA 7A85-T7452 is very sensitive to intergranular corrosion.SP would significantly improve its intergranular corrosion resistance.This is attributed to the combination action of residual compressive stress and grain refinement.PEO would reduce the largest corrosion depth by 41.6%.Moreover,PEO without sealing did not eliminate the intergranular corrosion due to the existence of the micropores and microcracks in the oxide coating.However,PEO combined with the SiO2sol–gel sealing treatment could effectively protect the AA 7A85-T7452 from intergranular corrosion because of the good corrosion resistance and barrier function of the sealed coating. 相似文献
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Feng Ge Lin Fan Jianming Liang Kun Pang Han Li Xin Wang Zhongyu Cui 《金属学报(英文版)》2021,34(12):1679-1694
The corrosion evolution of 2024-T351 and 7075-T651 aluminum alloys in the thin electrolyte layer (TEL) and wet-dry alter-nating cycle (WDAC) environment is studied in this work.The results show that in the TEL environment,the competitive effect between H+ that accelerates corrosion reactions and deposition of aluminum sulfate that impedes corrosion attacks exists during the corrosion exposure.The difference is that with increasing HSO3-,subsurface intergranular corrosion on 2024-T351 is promoted to form exfoliation corrosion eventually and the degree of exfoliation corrosion begins to decrease because the blocking effect of aluminum sulfate exceeds the expediting effect of H+.For 7075-T651,the corrosion area and the corrosion diameter decrease gradually,which is attributed to the HSO3-enhanced deposition of corrosion products and their blocking effect.In the WDAC environment,the corrosion processes of 2024-T351 and 7075-T651 are the acidic dissolution of the matrix during the soaking phase.When the HSO3-concentration is high enough (0.1 M),the inhibiting effect of aluminum sulfate becomes the dominant factor. 相似文献
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Xiu-Rong Zhu Jun Wang Wei-Ning Shi Xue-Bing Liu Xin-Fang Zhang Hai-Fei Zhou 《金属学报(英文版)》2022,35(9):1547-1558
Controlling the precipitation through thermomechanical treatment is an important method to improve the corrosion resistance of Al–Cu–Mg alloys. In this study, the corrosion behaviors of Al–Cu–Mg alloys in the solution-treated state and retrogressiontreated state under cold rolling deformation and then natural aging were investigated. In the solution-treated series alloys, the cold-rolled deformation improved the resistance to intergranular corrosion by suppressing the precipitation of the S-phas... 相似文献
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《腐蚀工程科学与技术》2013,48(3):155-159
AbstractCorrosion rates of three alloys of aluminium (28, 3S and M57S) and the inhibitive efficiency of agar-agar, dextrin and gelatin at three concentrations have been determined in 0·3 M NaOH solution at 22°, 40° and 60°c. The corrosion rate increases with increase in the quantity of impurities in the alloys, with the period of immersion and with temperature. Agar-agar is a more efficient inhibitor than are dextrin or gelatin at temperatures up to 40°c. None of the inhibitors could give satisfactory protection of alloy M57S, nor of any of the three alloys at 60°c. The adsorption characteristics of the inhibitors follow Temkin's isotherm. 相似文献