铁基非晶及纳米晶合金在NaOH溶液中的耐蚀性比较

冶炼制备了纳米晶Fe73.5Si13.5B9Nb3Cu1和非晶带材Fe78Si13B9。在电化学工作站上测试了两种合金在不同浓度的NaOH碱溶液里的极化曲线。随着NaOH溶液浓度的不同,非晶Fe78Si13B9和纳米晶Fe73.5Si13.5B9Nb3Cu1合金极化曲线具有相似的变化规律,且纳米晶合金比非晶合金的腐蚀电位要高,耐腐蚀性要好。     

20SiMn钢在恒定pH值的碳酸盐溶液中的腐蚀行为

采用电化学技术(动电位极化曲线,自腐蚀电位,EIS,Mott-Schottcky(MS)曲线及循环伏安曲线)和表面分析方法(SEM和原位Raman光谱)研究了空冷20SiMn钢在pH值均为10.64的3种浓度的碳酸盐缓冲液和浓度恒定为0.437×10-3mol/L的NaOH溶液中的腐蚀行为.结果表明,20SiMn钢在NaOH溶液中发生了均匀腐蚀,经Fe(OH)2转变为最终产物a-Fe2O3和g-FeOOH;在低浓度碳酸盐缓冲液中发生了局部腐蚀,经绿锈GRs得到最终腐蚀产物a-Fe2O3和bFeOOH;在高浓度碳酸盐缓冲液中发生了钝化,并且受可溶性离子Fe(CO3)22-的影响,钝化膜的耐蚀性随碳酸盐总浓度的升高存在极值.     

Al-Mg-Sn-Si-In铝合金在不同溶液中的腐蚀与电化学性能研究

研究了Al-0.5Mg-0.1Sn-0.1Si-0.02In合金作为铝空气电池的阳极材料,在2 mol/L NaCl,4 mol/L NaOH乙醇-10%水,4 mol/L NaOH溶液中的腐蚀行为及电化学性能。结果表明,该合金在4 mol/L NaOH乙醇-10%水溶液中性能优良,具有较高的阳极利用率及较低的自腐蚀速率。腐蚀形貌及电化学阻抗谱测试结果与合金腐蚀特性一致。通过对比Zn在4 mol/L NaOH溶液中的电化学性能,Al-0.5Mg-0.1Sn-0.1Si-0.02In合金在4 mol/L NaOH乙醇-10%水介质中作为铝空气电池的阳极材料具有可行性。     

环氧树脂/重结晶碳化硅复合材料的抗腐蚀性能

以E44型环氧树脂(EP)为填充材料,制备了环氧树脂填充重结晶碳化硅(EP/RSiC)复合材料。通过对表面形貌、动态电位极化曲线、电化学阻抗图谱、腐蚀速率进行分析,研究了EP/RSiC在静态室温条件下2 mol/L H_2SO_4溶液和4 mol/L NaOH溶液中的腐蚀行为。结果表明:EP/RSiC复合材料结构致密,具有较低的腐蚀电流密度和较高的自腐蚀电位,抗腐蚀性良好。EP/RSiC复合材料的腐蚀由SiC的活性溶解造成,因此EP/RSiC复合材料更容易受到碱性溶液的腐蚀,并且其腐蚀行为受电荷传递控制;EP/RSiC复合材料的腐蚀速率随EP填充量的增加而减少。15%(体积分数)EP/RSiC的抗腐蚀性最佳,在2 mol/L H_2SO_4溶液中的腐蚀速率为152 mg/(dm~2·d),在4 mol/L NaOH溶液中的腐蚀速率为310 mg/(dm~2·d),与RSiC相比其腐蚀保护效率分别达到90.5%和93.7%。     

1Cr13Mo3钢的显微组织及其在稀盐酸中的耐蚀性能研究

在1Cr13Mo3钢的基础上设计了两种不同成分的合金钢(S1合金钢中添加了0.3%Sn、0.3%Sb和0.4%Cu,S2合金钢中添加了0.6%Sn、0.4%Cu),通过真空悬浮炉熔炼得到铸态合金钢,研究了室温(20℃左右)条件下两种合金在1%、3%和5%三种浓度盐酸溶液中的腐蚀行为,并对两种材料在三种盐酸溶液中的腐蚀性能和腐蚀机理进行研究。结果表明,合金钢S1耐蚀性强于合金钢S2,室温下,随着盐酸溶液浓度增加,铸态合金钢S1、S2的腐蚀电位均正向移动,极化曲线出现钝化区并变窄,极化电阻变小,自腐蚀电流密度增加,腐蚀速率加快;1Cr13Mo3钢中Sn、Sb、Cu的加入相比Sn、Cu的加入更能提高材料在盐酸溶液中的耐腐蚀性能。     

稀土元素添加对铁基非晶复合材料腐蚀行为的影响

采用工业级原料经包覆剂(CaO-Fe_2O_3-SiO_2)处理制备了Fe-15Mn-5Si-14Cr-0.2C和添加稀土元素Ce、Dy及Ce+Dy的非晶复合材料棒状试样,用XRD和TEM研究不同稀土元素对复合材料微观组织的影响,用电化学工作站三电极体系分析试样在1 mol/L的HCl及1 mol/L的NaOH中的腐蚀行为。结果表明:合金在添加稀土元素后的组织仍为非晶复合材料,晶体相为过冷奥氏体相CFe_(15.1)和铁素体相Fe-Cr。加入质量分数1%Ce的试样在HCl及NaOH中的耐蚀性均为最佳,在HCl中自腐蚀电位为–0.162 05 V,自腐蚀电流密度为7.6999×10~(-8) A·cm~(-2),极化阻值达到9.5774×10~8Ω·cm~2;在NaOH中自腐蚀电位和自腐蚀电流密度分别为–0.1839 V,1.7453×10~(-8) A·cm~(-2),极化阻值为7.1574×10~8Ω·cm~2。耐蚀性远优于AISI304,是潜力巨大的耐蚀材料。     

含有Nb、Ce的形状记忆合金FeMnSiCrNi在3.5%NaCl溶液中的空蚀行为

利用超声波振动仪研究形状记忆合金Fe-14Mn-6Si-9Cr-5Ni-Nb-Ce在3.5%NaCl溶液中的空蚀行为,并探讨合金在3.5%NaCl溶液中处于静态和空蚀情形下的自腐蚀电位和极化曲线.结果表明,Fe-14Mn-6Si-9Cr-5Ni-Nb-Ce合金在3.5%NaCl溶液中呈现优异的抗空蚀性能,空蚀率为0.37 mg/h.空化能使Fe-14Mn-6Si-9Cr-5Ni-Nb-Ce合金的自腐蚀电位变负,变化量为-65 mV.在静态和空化两种条件下,Fe-14Mn-6Si-9Cr-5Ni-Nb-Ce合金在3.5%NaCl溶液中的自腐蚀电流密度都很低,因此合金具有优异的抗腐蚀性能,其纯腐蚀率和力学效应诱导的腐蚀率仅占空蚀率的2.24%.     

FeSiB/FeCuNbSiB合金在NaOH溶液中耐腐蚀性能及其对软磁性能的影响（英文）

非晶Fe78Si9B13和纳米晶Fe73.5Cu1Nb3Si13.5B9合金由于具有低矫顽力、高磁导率和高饱和磁通密度等特点而受到广泛关注。研究了Fe78Si9B13及Fe73.5Cu1Nb3Si13.5B9合金在NaOH(pH=9~10)溶液中的耐腐蚀性能,及其对软磁性能的影响。分析了经腐蚀后合金的有效磁导率、矫顽力和饱和磁感应强度等软磁性能的改变。样品用X射线衍射和3D高景深显微镜进行表征。结果显示:腐蚀后溶液中有橙色铁的氧化物产生,合金结构保持不变。经腐蚀后Fe78Si9B13及Fe73.5Cu1Nb3Si13.5B9合金的软磁性能下降,且Fe78Si9B13非晶合金的有效磁导率ue和饱和磁感应强度Bs比Fe73.5Cu1Nb3Si13.5B9纳米晶合金下降快。     

Corrosion Resistance of FeSiB and FeCuNbSiB Alloys and Its Influence on Their Soft Magnetic Properties in NaOH Solution

非晶Fe78Si9B13和纳米晶Fe73.5Cu1Nb3Si13.5B9合金由于具有低矫顽力、高磁导率和高饱和磁通密度等特点而受到广泛关注。研究了Fe78Si9B13及Fe73.5Cu1Nb3Si13.5B9合金在NaOH(pH=9~10)溶液中的耐腐蚀性能,及其对软磁性能的影响。分析了经腐蚀后合金的有效磁导率、矫顽力和饱和磁感应强度等软磁性能的改变。样品用X射线衍射和3D高景深显微镜进行表征。结果显示:腐蚀后溶液中有橙色铁的氧化物产生,合金结构保持不变。经腐蚀后Fe78Si9B13及Fe73.5Cu1Nb3Si13.5B9合金的软磁性能下降,且Fe78Si9B13非晶合金的有效磁导率ue和饱和磁感应强度Bs比Fe73.5Cu1Nb3Si13.5B9纳米晶合金下降快。     

Ni/Cu定向结构涂层在不同浓度H2SO4中的耐蚀性能

为了研究Cu元素对Ni基合金定向结构涂层耐腐蚀性能的影响,向Ni60合金粉末中添加了5%Cu(质量分数,下同),制备了定向结构Ni60/Cu复合涂层。采用电化学试验和浸泡试验,评估了涂层在不同浓度H₂SO₄溶液中的电化学腐蚀特性和浸泡腐蚀性能,探讨了涂层在不同浓度H₂SO₄溶液中的腐蚀行为。结果表明,涂层在不同浓度H₂SO₄溶液中的腐蚀均表现为活化-钝化-过钝化的过程,电化学阻抗谱在整个时间常数内具有典型的容抗特征,H₂SO₄溶液浓度从5%增至80%时,电荷转移电阻先减小后增大,涂层的耐腐蚀性呈现先降低后升高的趋势。随着H₂SO₄溶液浓度的增加,涂层表面的腐蚀程度先加剧后逐渐减缓,且在H₂SO₄溶液浓度为40%时,腐蚀电位移至最负,腐蚀电流密度增至最大。但在H₂SO₄溶液浓度达到80...     

The corrosion behavior of Fe-based shape memory alloys

Fe-30Mn-6Si, Fe-30Mn-6Si-5Cr and Fe-13Mn-5Si-12Cr-5Ni shape memory alloys were prepared by a VIM technique. The various corrosion tests were conducted to investigate the corrosion behaviors of these alloys. Experimental results show that in 3.5% NaCl solution, the Fe-13Mn-5Si-12Cr-5Ni alloy had the best chemical corrosion resistance, whereas the Fe-30Mn-6Si-5Cr alloy was locally attacked, forming many corrosion pits after immersion test. In addition, the detachment of the corrosion product covering the Fe-30Mn-6Si alloy caused an abrupt increase in the weight loss. After 2 h of heat treatment at 1000 °C, the corrosion potential of the Fe-30Mn-6Si alloy increased due to the formation of α-ferrite, while the Fe-30Mn-6Si-5Cr alloy became more active. In the stress-corrosion cracking test, the Fe-13Mn-5Si-12Cr-5Ni alloy, having the highest fracture stress in the atmosphere among these alloys, exhibited the largest decrease in fracture stress in the saturated H₂S solution due to the existence of α-martensite.     

Sintered Cu Alloyed Stainless Steels and Their Corrosion Behavior

Copper is an effective element to activate the sintering process of stainless steels and to enhance corrosion resistance of the sintered specimens. Ways of introducing Cu into stainless steel powders lead to different consequence in the microstructure and corrosion behavior of sintered Cu alloyed stainless steel. In the present work, two methods, mixing Cu with stainless steel powder and coating stainless steel powder with Cu by electroless plating, were introduced in order to investigate their influence on the sintered specimens. It was found that the sintered specimens from Cu-coated stainless steel powders (1-5 wt.%Cu) produce less porous surfaces with isolated pores than the specimens from mixed powders and the former have obviously high density and relatively even Cu distribution. Potentiodynamic polarization measurements indicate that Cu-electroless plating of 1-5 wt.%Cu improves the corrosion resistance of sintered stainless steel due to the lowering of passivation current density.     

激光熔覆Ni2Si／Ni3Si2金属硅化物合金涂层显微组织与耐蚀性

以Ni76Si24（质量百分数）合金粉末为原料，利用激光熔覆技术在A3钢表面制得了组织由条件Ni2Si初生相及少量Ni2Si/Ni3Si2共晶组成的新型金属硅化物合金涂层，分析涂层显微组织并测定其在0．5mol/1 H2SO4水溶液及不同浓度NaCl水溶液中的阳极极化曲线，结果表明激光熔覆Ni2Si/Ni3Si2金属硅化物合金涂层表面平整，组织细小，与基体为完全冶金结合，同时由于涂层的组织组成相Ni3Si2本身均具有极好的耐蚀性并具有快速凝固细小均匀的显微组织，该激光熔覆Ni2Si/Ni3Si2金属硅化物合金涂层在0．5mol/l H2SO4及3．5％NaCl水溶液中均具有优良的耐蚀性能。     

Corrosion performance of high pressure die-cast Al-6Si-3Ni and Al-6Si-3Ni-2Cu alloys in aqueous NaCl solution

The corrosion performance of high pressure die-cast Al-6Si-3Ni (SN63) and Al-6Si-3Ni-2Cu (SNC632) alloys in 3.5% (mass fraction) NaCl solution was investigated. X-ray diffraction (XRD) and microstructural studies revealed the presence of single phase Si and binary Al₃Ni/Al₃Ni₂ phases along the grain boundary. Besides, the single Cu phase was also identified at the grain boundaries of the SNC632 alloy. Electrochemical corrosion results revealed that, the SNC632 alloy exhibited nobler shift in corrosion potential (?_corr), lower corrosion current density (J_corr) and higher corrosion resistance compared to the SN63 alloy. Equivalent circuit curve fitting analysis of electrochemical impedance spectroscopy (EIS) results revealed the existence of two interfaces between the electrolyte and substrate. The surface layer and charge transfer resistance (R_ct) of the SNC632 alloy was higher than that of the SN63 alloy. Immersion corrosion test results also confirmed the lower corrosion rate of the SNC632 alloy and substantiated the electrochemical corrosion results. Cu addition improved the corrosion resistance, which was mainly attributed to the absence of secondary Cu containing intermetallic phases in the SNC632 alloy and Cu presented as single phase.     

Microstructural evolution of direct chill cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy during solution treatment

Heat treatment has important influence on the microstructure and mechanical properties of Al-Si alloys. The most common used heat treatment method for these alloys is solution treatment followed by age-hardening. This paper investigates the microstructural evolution of a direct chill (DC) cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy after solution treated at 500, 510, 520 and 530℃, respectively for different times. The major phases observed in the as-cast alloy are α-aluminum dendrite, primary Si particle, eutectic Si, Al7Cu4Ni, Al5Cu2Mg8Si6, Al15(Cr, Fe, Ni, Cu)4Si2 and Al2Cu. The Al2Cu phase dissolves completely after being solution treated for 2 h at 500℃, while the eutectic Si, Al5Cu2Mg8Si6 and Al15(Cr, Fe, Ni, Cu)4Si2 phases are insoluble. In addition, the Al7Cu4Ni phase is substituted by the Al3CuNi phase. The α-aluminum dendrite network disappears when the solution temperature is increased to 530℃. Incipient melting of the Al2Cu-rich eutectic mixture occurrs at 520℃, and melting of the Al5Cu2Mg8Si6 and Al3CuNi phases is observed at a solution temperature of 530℃. The void formation of the structure and deterioration of the mechanical properties are found in samples solution treated at 530℃.     

2,3-二巯基丁二酸对铜的缓蚀性能研究

目的以马来酸为原料制备2,3-二巯基丁二酸(DMSA),研究DMSA对铜在0.5 mol/L NaOH溶液中的缓蚀作用。方法以马来酸为原料,通过加成、消去、加成再水解的方法制备2,3-二巯基丁二酸,利用红外光谱和质谱对其结构进行表征。通过静态腐蚀失重实验研究铜在添加不同含量DMSA的NaOH溶液中的腐蚀速度,采用极化曲线和交流阻抗谱技术研究铜在添加不同含量DMSA的NaOH溶液中电化学行为,并用电子扫描电镜观察铜表面腐蚀形貌。结果红外光谱和质谱结合证明,目标产物为DMSA。铜在DMSA质量浓度分别为0,2.5,5.0 g/L的NaOH溶液中的腐蚀速率分别为7.60,3.25,2.13μg/(cm2·h)。当NaOH溶液中DMSA的质量浓度为5.0 g/L时,缓蚀率可达到94.92%。结论 DMSA在铜表面的吸附能降低水分子的侵蚀,增大铜表面的腐蚀产物膜电阻和电荷转移电阻,属于阳极型缓蚀剂。     

Fe基非晶及纳米晶合金的制备和电化学腐蚀行为

分别采用单辊甩带法和非晶晶化退火法制备出非晶及纳米晶合金Fe73.5Si13.5B9Nb3Cu1;利用DSC、XRD和TEM对该非晶合金的晶化行为进行了分析;并用电化学极化曲线的方法和电化学阻抗技术研究了该非晶合金经不同温度退火后在1mol/LHCl溶液里的电化学腐蚀行为。结果表明,该非晶合金的晶化过程出现2个阶段。当退火温度为500℃时,合金尚未晶化,仍保持非晶态;当温度达到550℃时,出现了晶化衍射峰,晶粒平均直径约13nm;当温度达到600℃时,晶粒平均直径约为15nm。经过退火得到的纳米晶合金的腐蚀电位大于未退火的非晶,且阳极电流密度变得更低,表明纳米晶状态时的耐腐蚀性能比非晶状态的更好。该非晶合金未退火、550℃退火和600℃退火时的EIS均由单一容抗弧构成,具有一时间常数;且随着退火温度升高,电化学反应电荷转移电阻在增大。     

铜镍合金铸铁耐碱腐蚀性能研究

采用动态失重法测定铜镍合金铸铁在高温浓碱液中的腐蚀速度,借助光学显微镜和扫描电镜观察显微组织和表面腐蚀形貌,利用能谱仪分析表面微区成分。结果表明,微观基体上富集的铜和镍有利于提高铜镍合金铸铁的耐蚀性,在高温浓碱液中的动态腐蚀条件下,铜含量为4.5%的D3试样耐碱蚀性较好。当铜含量超过一定值时,铜镍合金铸铁中析出游离铜相,这些新相成为活性阴极相,降低铸铁的耐蚀性。