海水腐蚀对几种金属材料耐磨性能的影响

研究TC4钛合金、Hastelloy C-276合金、Inconel 625合金和Monel K500合金与316不锈钢对磨时在纯水和模拟海水下的摩擦磨损行为,评价海水腐蚀环境对几种耐海水腐蚀材料耐磨性的影响以及316不锈钢与几种金属配副的磨损行为。结果表明,四对摩擦配副在纯水润滑条件下的摩擦系数明显大于其在海水润滑条件下的摩擦系数,海水具有较好的润滑作用。在腐蚀磨损过程中,腐蚀磨损交互作用量占总腐蚀磨损量的比例ΔV/V为45%~86%,表明在海水环境下腐蚀与磨损的交互作用不可忽视。与不同金属对磨时,316不锈钢对偶材料的磨损量表现出不同的趋势,这可能与摩擦过程中存在的电偶腐蚀有关。     

AISI 316不锈钢和Ti6Al4V合金在海水环境中的腐蚀与腐蚀磨损行为(英文)

采用立式万能销盘腐蚀磨损试验机研究AISI 316不锈钢和Ti6Al4V合金在海水中与Al2O3陶瓷对磨时的腐蚀与腐蚀磨损行为,重点讨论腐蚀磨损之间的交互作用。结果表明,摩擦作用使得Ti6Al4V合金和316不锈钢的开路电位大幅下降,腐蚀磨损过程中的电流密度远高于静态腐蚀时的电流密度,摩擦明显促进了合金的腐蚀。两种合金在海水中的磨损量远大于在纯水中的磨损量,腐蚀促进了磨损,并且Ti6Al4V合金的耐磨性优于316不锈钢的耐磨性,腐蚀磨损之间的交互作用是材料损失的一个重要因素。本实验所用的摩擦装置为单向滑动的面面接触方式,这使得摩擦对腐蚀的促进作用在总磨损量中所占的比例很小。     

微观组织特征对模拟海水中搅拌摩擦加工Ti-6Al-4V合金腐蚀磨损性能的影响

目的研究搅拌摩擦加工细晶Ti-6Al-4V合金在模拟海水中微观组织特征与腐蚀磨损性能的关系。方法通过控制搅拌摩擦加工工艺(200 r/min-25 mm/min和200 r/min-50 mm/min)获得具有等轴细晶组织和片层状α相组织的Ti-6Al-4V合金。使用往复磨损试验机和电化学工作站,在模拟海水中对Ti-6Al-4V合金进行腐蚀磨损实验,获得摩擦系数-时间曲线、动电位极化曲线等一系列摩擦磨损和电化学曲线。使用激光共聚焦显微镜和扫描电子显微镜对磨痕进行观察,计算磨损率,并分析磨损机制。通过计算腐蚀磨损分量研究材料损耗的主要影响因素。结果在腐蚀磨损中,因表面氧化膜被破坏,具有细晶结构的Ti-6Al-4V合金晶界面积大,腐蚀电位降低,但腐蚀电流密度小于原始试样。搅拌摩擦加工试样在腐蚀磨损实验中的摩擦系数更稳定,OCP条件下,具有细小等轴晶组织的搅拌摩擦加工Ti-6Al-4V合金的摩擦系数最低,磨损率较原始试样低20%。片层组织特征Ti-6Al-4V合金因微观力学性能各向异性而影响对磨球的行进路线,犁沟较混乱。原始样品的磨损机制主要为磨粒磨损和腐蚀磨损,搅拌摩擦加工后,样品在模拟海水中的磨损机制为磨粒磨损、分层磨损和腐蚀磨损。结论等轴细晶组织Ti-6Al-4V合金在模拟海水中表现出低的磨损率和低的摩擦系数,该组织特征具有最优的耐腐蚀磨损性能。     

AISI316不锈钢腐蚀磨损交互作用的研究

采用电化学方法、微观形貌观察以及失重法分析研究了AISI 316不锈钢和Al2O3陶瓷摩擦副在模拟海水中的腐蚀磨损行为,探讨了摩擦对不锈钢腐蚀行为的影响以及腐蚀磨损交互作用。结果表明,在本实验条件下摩擦作用显著增加了AISI 316不锈钢的腐蚀倾向,其腐蚀率显著增加。纯磨损量占总腐蚀磨损量的76%~88%,材料的损失主要是由摩擦作用所引起,腐蚀磨损交互作用量占总腐蚀磨损量的12%~24%,腐蚀磨损交互作用是影响材料耐磨蚀性能的重要因素。     

人工模拟体液中pH值对离子注N人体医用合金腐蚀行为的影响

采用电化学测试技术研究了在人工模拟体液中pH值变化对离子注N人体用SUS316L不锈钢,Co-Cr合金,工业纯Ti和Ti-6Al-4V合金腐蚀行为的影响。结果表明,随着pH值的降低,试样的腐蚀电位负移,SUS316L不锈钢和Co-Cr合金的点蚀电位与缝隙腐蚀电位降低,使材料发生局部腐蚀的敏感性提高,工业纯Ti和Ti-6Al-4V合金的腐蚀电流密度增大,提高离子释放速度,加大对人体的潜在生理危害。     

LY12微弧氧化膜在不同水溶液中的摩擦学行为

以球一面接触方式,在500 μm振幅下,研究LY12铝合金微弧氧化膜在人造雨水、人造海水和纯净水等3种介质中的往复滑动摩擦学行为,研究载荷、频率以及环境介质对摩擦因数和磨损质量损失的影响.结果表明,氧化膜在3种水溶液中的摩擦因数均随着频率的升高而下降,随载荷的上升则呈不同的变化趋势;摩擦因数按照以下顺序递减:雨水、纯水、海水,说明水溶液对摩擦因数的影响,尤其是海水显著的减摩作用;低频时,纯水中的磨损体积最大;随着频率上升,由于Cl-对基体的腐蚀效应以及对磨损的促进作用,导致LY12微弧氧化膜在海水和雨水中的磨损量快速上升而超过纯水中的磨损量,使得腐蚀磨损呈正的交互作用.     

模拟海水环境中电化学状态对TC4钛合金腐蚀磨损行为的影响（英文）

采用摩擦失重法、电化学测试以及扫描电子显微镜等技术研究TC4钛合金在模拟海水环境中的腐蚀和腐蚀磨损行为,分析电化学状态对TC4钛合金钝化行为、钝化膜失效机制及腐蚀磨损协同作用的影响。结果表明,摩擦过程中TC4钛合金的开路电位明显负移,而且该合金的腐蚀电流密度相比静态腐蚀时提高了3个数量级。合金的腐蚀磨损失重随着电位的升高明显增大,磨蚀与磨损之间存在明显的协同作用,高电位时的腐蚀速度较大但是摩擦因数较低。电位在OCP和0.9 V之间变化时,纯机械磨损量在总腐蚀磨损量中的比重随着电位的升高逐渐降低,而磨损对腐蚀的促进量和腐蚀对磨损的促进量在总腐蚀磨损量中的比重在高电位时尤其显著。     

Ti-6Al-4V合金氮离子注入后在Tyrode’s体液中的耐蚀耐磨性能

Ti-6Al-4V合金注入氮离子后,生物相容性、抗磨损性、抗疲劳性及抗腐蚀性均有所提高,其植入人体后在体液中的耐蚀耐磨性能尤为重要,目前对此研究较少。对Ti-6Al-4V合金进行氮离子注入,并在人工模拟体液Tyrode’s溶液中进行摩擦磨损和电化学试验,研究了注氮Ti-6Al-4V合金的耐蚀耐磨性能。采用扫描电镜观察腐蚀形貌,用其自带的能谱仪分析注氮层的元素组成,采用X射线衍射仪分析注氮层的结构。结果表明:Ti-6Al-4V氮离子注入后表面形成主要由TiC,Ti及少量TiO2组成的膜层,硬度提高,在Tyrode’s溶液中的腐蚀电位升高、极化电阻增大,阳极极极化电流密度降低;在Tyrode’s溶液中摩擦后的注氮Ti-6Al-4V合金的阳极极化电流密度大于未摩擦的,极化电阻减小;Ti-6Al-4V合金氮离子注入后的摩擦系数明显降低,比磨损率减少。     

Ti-6Al-4V热浸镀铝涂层干滑动磨损行为的实验研究

Ti-6Al-4V合金经热浸铝并在650℃下进行高温扩散退火处理,获得TiAl3涂层。采用销-盘式磨损试验机研究铝化后的Ti-6Al-4V合金与GCr15钢对磨的干滑动磨损行为。通过SEM、XRD、EDS和XPS等微观分析手段测试热浸镀铝涂层磨面的形貌、物相和成分,并且探讨其磨损机制。研究结果表明：随着滑动速度的增加,当滑动速度为0.75m/s时,铝化后的Ti-6Al-4V合金的磨损量先减小到最小值,然后在2.68m/s时增加到最高值,最后在4m/s时降至最低值。在不同的滑动速度下,磨损量随着载荷的增加而增加。研究发现,摩擦层结构对磨损的行为和机制有显著的影响。在4m/s时,含氧的摩擦层(TiO和TiO2)具有明显的减磨性能;相反地,在2.68m/s时,没有氧化物的摩擦层并未显示出对磨损具有保护作用。与未经热浸镀处理的Ti-6Al-4V合金相比,在不同工况下,铝化后的涂层提高了钛合金的耐磨性,尤其速度为4m/s。耐磨性得到提高是由Ti-Al涂层和摩擦氧化物层所引起的。     

TIG堆焊Co-9Al-7.5W合金堆焊层的显微组织和耐磨性能

Co-Al-W合金是由γ′-Co3(Al,W)相沉淀强化的新型钴基高温合金。为了研究Co-Al-W合金在不锈钢基体上TIG堆焊性能及堆焊层合金的耐磨性能,运用TIG方法在304不锈钢基体上堆焊Co-9Al-7.5W合金,用THT07 135型高温摩擦磨损试验机、SEM等方法研究了堆焊层Co-9Al-7.5W合金与SiN圆环配磨的摩擦因数,并与相同条件下钴基Stellite 6合金的摩擦磨损性能进行了比较。结果表明:TIG堆焊Co-9Al-7.5W合金的最佳工艺参数为堆焊电流100 A,堆焊电压12 V,热输入功率10.3 kJ/cm。此时,堆焊层7.5W合金表面的硬度高达HRC53.1。堆焊层7.5W合金的磨损质量损失随摩擦时间的增加而增大,平均摩擦因数为0.471,而相同条件下,Stellite 6合金的摩擦因数为0.531,故堆焊层7.5W合金的耐磨性能较好。堆焊层7.5W合金主要发生氧化磨损和磨粒磨损,但Stellite 6合金主要发生剥层磨损和磨粒磨损。     

Assessing the tribocorrosion performance of Ti–6Al–4V, 316 stainless steel and Monel K500 alloys in artificial seawater

The electrochemical and tribocorrosion behaviors of Ti–6Al–4V, 316 stainless steel and Monel K500 alloys sliding against Al₂O₃ in artificial seawater are investigated in this paper. It can be observed that the open circuit potential drops down to more negative values due to the removal of passive film. And a rapid dissolution occurs in the wear track compared with the unworn area. The wear loss polarized in cathodic potential is lower than that in anodic potential and open circuit potential conditions, because the material deterioration is enhanced by corrosive attack. The wear volumes of 316 stainless steel are much higher than the ones measured for Ti–6Al–4V and Monel K500 alloys. Friction coefficients are significant large in cathodic polarization compared with anodic polarization for all alloys. Moreover, the 316 stainless steel exhibits large friction coefficients compared with Ti–6Al–4V and Monel K500 alloys.     

炼油加工过程中氯离子与硫离子对 316L 不锈钢和Monel 合金腐蚀的影响

目的研究常减压装置高温原油馏分及塔顶水相中氯离子、硫离子含量对316L不锈钢和Monel合金(镍基合金)腐蚀的影响。方法通过腐蚀挂片实验,获得316L不锈钢和Monel合金在含不同浓度氯离子和硫离子的水相、油相中的腐蚀速率变化规律。利用扫描电子显微镜,研究316L和Monel合金表面腐蚀后的微观形貌,探讨两种离子对316L不锈钢和Monel合金腐蚀的影响规律。结果在酸值较高的脱后原油中,316L不锈钢和Monel合金的腐蚀速率分别为0.0091,0.0248 mm/a;在酸值较低的常二段馏分中,316L不锈钢和Monel合金的腐蚀速率分别为0.0078,0.0031 mm/a。在常二段馏分中,加入600mg/L氯离子和30 mg/L硫化钠时,316L不锈钢和Monel合金的腐蚀速率分别为0.1755,0.1707 mm/a。在相同条件的脱后原油中,316L不锈钢的腐蚀速率为0.0545 mm/a,Monel合金的腐蚀速率为0.1281mm/a。结论油相中氯离子含量较低时,环烷酸腐蚀占主导因素;而氯离子含量达到较高水平后,氯离子对腐蚀的影响占主导作用。316L不锈钢和Monel合金的腐蚀速率都随氯离子含量的增加而增加,并且硫离子的存在对腐蚀也有一定的促进作用。在塔顶水相中,氯离子和硫离子均对Monel合金腐蚀的影响不大。     

添加晶粒细化剂硅对Ti-6Al-4V合金组织和性能的影响(英文)

采用真空感应凝壳熔炼工艺在石墨模中制备Ti-6Al-4V和Ti6Al4V0.5Si两种钛合金。将硅作为一种晶粒细化剂加入到Ti-6Al-4V合金中,考察添加硅对铸态和模锻态Ti-6Al-4V合金组织和性能的影响。铸态合金先在900°C下进行热模锻处理,然后分别进行两种不同的热处理。一种是将模锻样品在1050°C下保温30min,然后水淬以获得细小的层片状组织;另一种是将模锻件在1050°C下保温30min,然后再在800°C下保温30min,以获得粗大的层片状组织。Ti6-Al-4V合金中添加0.5%Si后,铸态合金的晶粒尺寸从627μm减小到337μm,其极限抗拉强度增加约25MPa。具有细小、层片状组织的Ti-6Al-4V0.5Si合金的最大极限抗拉强度为1380MPa,在Hank溶液和NaCl溶液中的腐蚀速度分别为1.35×106和5.78×104mm/a。Ti-6Al-4V合金中添加0.5%Si后,在低滑动速度下的磨损率降低50%,在高滑动速度下的磨损率降低约73%。     

Ti-6Al-4V合金在真空中的干滑动磨损行为

在真空(10^-^5Pa)条件下对Ti-6Al-4V合金进行了系统的磨损性能测试，研究了载荷和滑动速度对Ti-6Al-4V合金磨损率的影响．对Ti-6Al-4V合金的磨损表面进行了显微组织分析．实验结果表明，Ti-6Al-4V合金的磨损率随载荷和滑动速度的升高而增加．磨损表面具有层状结构的舌状形貌特征，分析表明这是Ti-6Al-4V合金表面通过接触点处材料的被推挤和碾压过程形成了特殊的变形堆砌层的结果．显微组织分析显示，这种变形堆砌层具有50—100nm尺寸的细小显微组织结构和50mm以上的厚度．     

Galvanic corrosion of A1 alloys — II. Effect of solution composition

Galvanic corrosion of the A1 alloys 1100, 2024, 2219, 6061 and 7075 coupled to Cu, stainless steel 304L, Ti-6A1-4V, 4130 steel or zinc has been studied in 3·5% MaCl, tapwater and distilled water using electrochemical and weight loss data. In 3·5% NaCl the galvanic effect decreases in the order Cu > 4130 steel > SS304L > Ti-6A1-4V for A1 alloys coupled to one of these metals, while in tapwater and distilled water the ranking is Cu > SS304L ～ Ti-6A1-4V > 4130 steel. Zinc, although being the anode in all galvanic couples, can sometimes accelerate corrosion rates of A1 alloys. Dissolution rates of A1 alloys coupled to a given dissimilar material are higher in 3·5% NaCl than in tapwater and distilled water where they are found to be comparable. In assessing galvanic corrosion behaviour of a given A1 alloy as a function of environment, one has to consider the effect of the dissimilar metal. The dissolution rate of A1 6061 is, for example, higher in tapwater with Cu as cathode than in 3·5% NaCl with SS304L or Ti-6A1-4V as cathode.     

Low-melting-point titanium-base brazing alloys—part 1: Characteristics of two-, three-, and four-component filler metals

The melting point, microstructure, phase, and electrochemical behavior of Ti-21Ni-15Cu alloy, together with two-, three-, and four-component low-melting-point titanium-base brazing alloys, are presented in this paper. Five filler metals were selected for the study, in which melting points were measured by differential thermal analysis, phases identified by x-ray diffractometry, and corrosion behaviors tested by potentiodynamic polarization. The experimental results show that the three-component Ti-15Cu-15Ni and the newly developed Ti-21Ni-14Cu alloys exhibit the combination of lower melting point and superior corrosion resistance compared to the two-and four-component titanium alloys, 316L stainless steel, and a Co-Cr-Mo alloy in Hank’s solution at 37 °C. On a short time basis, the presence of Ti₂Ni and Ti₂Cu intermetallics in the Ti-15Cu-15Ni and Ti-21Ni-14Cu alloys should not be preferentially dissolved in galvanic corrosion with respect to the dissimilar Ti-6Al-4V alloy.     

Depassivation of some metals by sliding friction

Nickel, TA6V4 alloy and 316L stainless steel were passivated in aerated sulphuric acid solution (0.5 M), and submitted to sliding friction against a loaded alumina ball. The effects of sliding speed and normal applied load on tribological behaviour of the passivating films were analyzed. Friction coefficients were measured and the metal wear rates were deduced from 3D profilometry recordings on the wear tracks. Current variations were also measured during friction tests and the results are discussed in terms of depassivation-repassivation kinetics induced by the passivating film breakdown. The effects of sliding speed and applied load on the depassivation kinetics and thus current enhancement due to friction were particularly studied. The Passivating film formed on nickel surface shows the best resistance to friction and wear, whereas TA6V4 alloy shows the worst behaviour. The Passivating film on this alloy wears easily leading to a high material consumption. 316L stainless steel situates between the two other materials.     

Effect of Microstructural Variation on Dry Sliding Wear Behavior of Ti-6Al-4V Alloy

The present article evaluates the influence of independent control factors such as microstructural variation, normal load, sliding velocity, and test duration on dry sliding wear behavior of Ti-6Al-4V alloy at room temperature using a statistical approach. Ti-6Al-4V alloy has been heat treated in a controlled manner in order to produce different microstructural features (i.e., lamellar, bimodal, and equiaxed). Lamellar microstructure is found to be harder than bimodal microstructure followed by equiaxed microstructure in Ti-6Al-4V alloy. Dry sliding wear tests have been carried out using a multiple Tribo tester following a well planned experimental schedule based on Taguchi’s L₉ orthogonal array design. Dry sliding wear behavior of Ti-6Al-4V alloy consisting of various microstructural features is related to their hardness values. Results indicated that lamellar microstructure has the lowest sliding wear resistance followed by bimodal and equiaxed microstructure. With the help of signal-to-noise ratios, optimal combination of control factors to minimize the dry sliding wear in Ti-6Al-4V alloy has been determined. Normal load is the most significant control factor influencing the dry sliding wear behavior of investigated Ti-6Al-4V alloy followed by sliding velocity, test duration, and microstructural variation. Normal load has greater static influence of 27.02%, sliding velocity has an influence of 18.07%, test duration has an influence of 12.71%, and microstructural variation has an influence of 10.55% on weight loss of Ti-6Al-4V alloy due to wear having R ² = 0.89. Two wear mechanisms have been identified: oxidative wear occurs at the lowest sliding velocity and delamination wear occurs at the highest sliding velocity. Optical microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and Rockwell hardness measurements have been used to characterize the microstructures in order to correlate the results obtained.     

不锈钢与GFER及CFRPEEK在海水润滑下的摩擦磨损特性

为了寻找适合于低速大扭矩海水液压马达的各摩擦副之间的配对材料,分别以不锈钢(316L和9Cr18Mo)与玻纤环氧复合材料(GFER)及碳纤维增强聚醚醚酮(CFRPEEK)为摩擦副,利用MMU-5G屏显式高温材料端面摩擦磨损试验机对摩擦副在海水中接触表面的温度、摩擦因数和摩擦磨损状况进行了测试,并通过激光共聚焦显微镜对接触表面的磨损形貌进行分析。结果表明:不锈钢/GFER的摩擦因数随着时间的变化在0.3~0.4间波动且幅度较大,而不锈钢/CFRPEEK的摩擦因数随着时间的增加稳定在0.1左右;不锈钢/GFER所引起海水温升的幅度也远远高于不锈钢/CFRPEEK;不锈钢/GFER的接触表面出现了大面积的涂抹与擦伤,且磨损程度要大于不锈钢/CFRPEEK;不锈钢316L的耐腐蚀性优于9Cr18Mo。由此可知,316L/CFRPEEK较适合作为低速大扭矩海水液压马达的摩擦副材料。