应用d—电子合金设计理论发展新型抗热腐蚀单晶镍基高温合金 Ⅲ.性…

根据ｄ－电子合金理论研究了合金系统Ｎｉ－１６Ｃｒ－９Ａｌ－２Ｗ－１Ｍｏ－４Ｃｏ－Ｔｉ－Ｔａ－Ｎｂ（ａｔ．－％）的热腐蚀行为。选择了最佳成分范围内的４种成分进行单晶生长及性能评价。确定了性能匹配最佳的合金成分（ａｔ．－％）为：Ｎｉ－１６Ｃｒ－９Ａｌ－２Ｗ－１Ｍｏ－４Ｃｏ－３．１２５Ｔｉ－０．８７５Ｔａ。完成了整个合金设计过程。该合金抗热腐蚀能力达到或超过ＩＮ７３８ＬＣ，使用温度比ＩＮ７３８ＬＣ高７０     

包覆钯和镍后MnNi5基贮氢合金的电化学特性

测定了包覆１０ｗｔ％Ｐｄ－Ｎｉ后Ｍｍ０．９Ｔｉ０．１Ｎｉ３．９Ｍｎ０．４Ｃｏ．４Ａｌ０．３合金，及由其制成Ｎｉ－ＭＨ电池的电化学特性。包覆Ｐｄ－Ｎｉ的贮氢合金电极２００次循环后容量仅衰减３％。负极为合金包覆Ｐｄ－Ｎｉ的Ｎｉ－ＭＨ电池在０．４Ｃ放电时的平均放电电压为１．２７Ｖ。在３Ｃ放电时的放电容量为０．４Ｃ的７６％。     

包覆钯和镍后M_mNi_5基贮氢合金的电化学特性

测定了包覆１０ｗｔ％Ｐｄ－Ｎｉ后Ｍｍ０．９Ｔｉ０．１Ｎｉ３．９Ｍｎ０．４Ｃｏ０．４Ａｌ０．３合金，及由其制成Ｎｉ－ＭＨ电池的电化学特性。包覆Ｐｄ—Ｎｉ的贮氢合金电极２００次循环后容量仅衰减３％。负极为合金包覆Ｐｄ—Ｎｉ的Ｎｉ－ＭＨ电池在０．４Ｃ放电时的平均放电电压为１．２７Ｖ。在３Ｃ放电时的放电容量为０．４Ｃ时的７６％。     

Fe—Mn─Al合金的腐蚀性能与钝化膜的研究

应用阳极极化及ＡＥＳ／ＸＰＳ技术,研究了Ｆｅ－３０．８Ｍｎ－８．２Ａｌ奥氏体合金在ｐＨ值为－０．８至１５．３的水溶液中的腐蚀性能,并与Ｆｅ－３０Ｍｎ合金、低碳钢、９％Ｎｉ低温钢及１Ｃｒ１３不锈钢进行对比。在所测试的水溶液中,该合金的腐蚀抗力优于低碳钢和Ｆｅ－３０Ｍｎ合金,与９％Ｎｉ钢相当,但不及１Ｃｒ１３不锈钢。Ｆｅ－３０．８Ｍｎ－８．２Ａｌ合金在１ｍｏｌ／ＬＮａ２ＳＯ个中形成的钝化膜的最表层可能为氢氧化物,而膜的主体由Ｆｅ２Ｏ３、Ｍｎ２Ｏ３及Ａｌ２Ｏ３组成。     

Ti—Mo—TiC烧结合金中TiC的腐蚀行为

纯钛虽说具有良好的耐蚀性,但对盐酸、硫酸等非氧化性酸的耐蚀性却不大好．在钛中添加２５％以上的钼时,对这些酸的耐蚀性可有实质上的改进．但这种钛钼合金熔炼时易偏析,因此开发了粉末冶金的Ｔｉ－３０％Ｍｏ合金,并在其中添加碳化物,以提高硬度和耐磨性,如Ｔｉ－Ｍｏ－（３３％～４５％） ＴｉＣ合金等．为明了合金中ＴｉＣ的腐蚀机制,用电位学方法研究了由β－Ｔｉ和ＴｉＣ两相构成的Ｔｉ－Ｍｏ－ＴｉＣ 烧结合金中的硬质相ＴｉＣ在几种酸碱溶液中的腐蚀行为． 使用的试样为Ｔｉ－２０％Ｍｏ－３３％ＴｉＣ合金（ＴＭ－２）和不…     

APPLICATIONS OF d-ELECTRONS ALLOY DESIGN THEORY TO DEVELOPMENT OF HOT CORROSION RESISTANT Ni－BASE SINGLE CRYSTAL SUPERALLOYS Ⅲ. Characterization of Properties

根据ｄ－电子合金理论研究了合金系统Ｎｉ－１６Ｃｒ－９Ａ１－２Ｗ－１Ｍｏ－４Ｃｏ－Ｔｉ－Ｔａ－Ｎｂ（ａｔ．－％）的热腐蚀行为。选择了最佳成分范围内的４种成分进行单晶生长及性能评价。确定了性能匹配最佳的合金成分（ａｔ．－％）为：Ｎｉ－１６Ｃｒ－９Ａ１－２Ｗ－１Ｍｏ－４Ｃｏ－３．１２５Ｔｉ－０．８７５Ｔａ。完成了整个合金设计过程．该合金抗热腐蚀能力达到或超过ＩＮ７３８ＬＣ，使用温度比ＩＮ７３８ＬＣ高７０－９０℃，其持久强度达到ＣＭＳＸ－２的水平，试验证明ｄ－电子合金设计理论可以用于研制开发高性能抗热腐蚀单晶镍基高温合金．     

应用d－电子合金设计理论发展新型抗热腐蚀单晶镍基高温合金──Ⅲ．性能评价

根据ｄ－电子合金理论研究了合金系统Ｎｉ－１６Ｃｒ－９Ａ１－２Ｗ－１Ｍｏ－４Ｃｏ－Ｔｉ－Ｔａ－Ｎｂ（ａｔ．－％）的热腐蚀行为。选择了最佳成分范围内的４种成分进行单晶生长及性能评价。确定了性能匹配最佳的合金成分（ａｔ．－％）为：Ｎｉ－１６Ｃｒ－９Ａ１－２Ｗ－１Ｍｏ－４Ｃｏ－３．１２５Ｔｉ－０．８７５Ｔａ。完成了整个合金设计过程．该合金抗热腐蚀能力达到或超过ＩＮ７３８ＬＣ，使用温度比ＩＮ７３８ＬＣ高７０－９０℃，其持久强度达到ＣＭＳＸ－２的水平，试验证明ｄ－电子合金设计理论可以用于研制开发高性能抗热腐蚀单晶镍基高温合金．     

Cu基形状记忆合金的时效

对比研究了时效对亚共析Ｃｕ－１２．０Ａｌ－５．０Ｎｉ－２．０Ｍｎ－１．０Ｔｉ（ｗｔ．－％）合金与Ｃｕ－２０．０Ｚｎ－６．０Ａｌ－微量Ｂ（ｗｔ．－％）合金热稳定性的影响。结果表明，无论在母相状态或马氏体相状态，Ｃｕ－Ａｌ－Ｎｉ合金的时效热稳定性均远优于Ｃｕ－Ｚｎ－Ａｌ合金。Ｃｕ－Ａｌ－Ｎｉ合金母相状态时效伴随着ＤＯ＿３有序畴长大，基体中Ａｌ、Ｎｉ、Ｍｎ等元素贫化，导致Ｍ＿ｓ点升高，马氏体转变量降低。Ｃｕ－Ｚｎ－Ａｌ合金母相状态时效伴随贝氏体转变，引起基体富Ｚｎ富Ａｌ，导致Ｍ＿ｓ点下降，马氏体量降低。Ｃｕ－Ａｌ－Ｎｉ合金高的时效热稳定性可能来源于Ｎｉ对Ａｌ、Ｃｕ等原子扩散的阻碍作用。     

铸造铬锰氮下锈钢耐蚀性的研究

添加了Ｍｏ和Ｃｕ的铬锰氮不锈钢，合金钝化膜更加完整，且稳定性高钝化膜主要由Ｆｅ，Ｃｒ和Ｍｏ的含水氧化物组成，添加Ｍｏ和Ｃｕ的合金钝化膜有Ｃｒ，Ｍｏ和Ｃｕ的富集，且Ｃｒ／Ｆｅ的比值高，膜薄却密，耐蚀性能好。它具有优于１８－８和１Ｃｒ１８Ｎｉ１２Ｍｏ２Ｔｉ钢的耐均匀腐蚀、耐点蚀和耐晶间腐蚀性能。     

Fe—Mn—Al合金的腐蚀性能与钝化膜的研究

应用阳极极化及ＡＥＳ／ＸＰＳ技术，研究了Ｆｅ－３０．８Ｍｎ－８．２Ａｌ奥氏体合金在ｐＨ值为－０．８至１５．３的水溶液中的腐蚀性能，并与Ｆｅ－３０Ｍｎ合金，低碳钢，９％Ｎｉ低温钢及１Ｃｒ１３不锈钢进行对比。在所测试的水溶液中，该合金的腐蚀抗力优于低碳钢的Ｆｅ－３０Ｍｎ合金，与９％Ｎｉ钢相当，但不及１Ｃｒ１３不锈钢。     

油气开采用钛合金石油管材料耐腐蚀性能研究

选取5种油气开发常用钛合金材料(Ti-6Al-4V、Ti-6Al-4V-0.1Ru、Ti-6Al-2Sn-4Zr-6Mo、Ti-3Al-8V-6Cr-4Zr-4Mo和Ti-5.5Al-4.5V-2Zr-1Mo)为研究对象,使用高温高压釜模拟国内典型严酷服役工况环境,研究了不同钛合金材料耐均匀腐蚀、局部腐蚀、点蚀、应力腐蚀开裂(SCC)及缝隙腐蚀的性能,通过使用扫描电镜和能谱分析等手段对腐蚀形貌和腐蚀产物进行了分析,并使用电化学方法对不同合金的耐腐蚀机理进行了研究。结果显示,在所测试工况条件下,所有钛合金材料腐蚀反应均为阳极控制过程,均匀腐蚀速率均低于0.001mm/a,并且对应力腐蚀开裂均有良好的抗力。Ti-6Al-4V和Ti-5.5Al-4.5V-2Zr-1Mo合金出现明显的点蚀和缝隙腐蚀问题。对腐蚀机理研究表明,在工况条件温度下,随着pH值的降低,所有钛合金均发生自腐蚀电位降低,极化电阻减小,腐蚀电流增大,耐腐蚀性能下降,其中Ti-6Al-4V耐腐蚀性能下降的最为明显,研究结果为油气开发工况下钛合金石油管的选材和缝隙腐蚀问题防治提供理论基础。     

Using Ti-5111 for marine fastener applications

Titanium offers virtually unsurpassed resistance to crevice, pitting, and stress-corrosion cracking in seawater environments. Ti-5Al-1Sn-1Zr-1V-0.8Mo (Ti-5111) is a near-alpha titanium alloy of intermediate strength, excellent toughness, and roomtemperature creep resistance designed in a U.S. Navy-sponsored titanium alloy development program for structural submarine applications. Ti-5111’s desirable mechanical properties and excellent corrosion resistance render this titanium alloy an ideal fastener material from both a technical and economic perspective. For more information, contact J. Been, Titanium Metals Corporation, Henderson Technical Laboratory, 8000 West Lake Mead Drive, Henderson, Nevada 89015; (702) 566-4413; fax (702) 564-9038; e-mail jenny.been@timet.com.     

Development of sintered Ti-30mass%Mo alloy and its corrosion properties

Ti-30mass%Mo alloy is characterized by far better corrosion resistance than pure titanium in non-oxidizing acid such as 35% HC1 solution. This alloy was newly developed in this work by a powder metallurgical process, because the conventional melting-casting process had difficulties in manufacturing the alloy owing to its heavy gravity segregation. The corrosion behavior of sintered Ti-30Mo alloy was studied by both immersion test and electro-chemical measurement. The corrosion rate of 1.3X10⁻²[mm/yearxxx] was obtained by immersion test in 35% HC1 solution, which was 10³ times superior to that of pure titanium. The potentio-dynamic polarization curve of this alloy in 35% HC1 solution showed more noble corrosion potential and lower anodic current density than those of pure titanium. The passive film formed on the alloy, in which Mo was enriched by preferential dissolution of titanium, thought to suppress the anodic reaction and improve its corrosion resistance.     

Crevice corrosion monitoring of titanium and its alloys using microelectrodes

Crevice corrosion of titanium and its alloys in 10% sodium chloride was investigated at 100°C with the aid of microelectrodes. Potential, pH and chloride ion concentration inside the crevice were monitored using an Ag/AgCl electrode, a tungsten microelectrode and a Ag/AgCl chloride ion selective microelectrode, respectively. The pH and Cl^? concentrations within the crevice were calculated from the standard potential‐pH and potential‐log[Cl^?] calibration curves. The effect of Mo on the crevice corrosion of titanium was also studied. The passivation behavior on the titanium and Ti‐15%Mo alloy was studied using electrochemical impedance studies. There was no apparent change in pH and Cl^? ion activity inside the crevice for the alloy at 100°C, whereas a marginal decrease in pH and increase in Cl^? ion concentration were observed for pure titanium. Thus pure titanium is susceptible to crevice corrosion in hot 10% NaCl solutions at 100°C. The chloride ion activity was found to be reduced for the alloy so that the pH inside the crevice increased. The corrosion reaction resistance (R_t) was found to increase with the addition of Mo as an alloying element. It also increases with externally applied anodic potential. Hence, Mo is an effective alloying element, which enhances the crevice corrosion resistance of titanium.     

钛合金及其油井管耐蚀性能研究进展

综述了油井管现状、钛合金组织与力学性能,重点探讨了钛合金作为油井管的耐蚀性能、影响因素与耐蚀机理,并对第一性原理计算在钛合金管材成分设计与界面腐蚀特征中的应用进行了概述。研究发现,钛合金管材具有较强的抗硫化物应力开裂(SSC)性能,在高温高压(HTHP)油气田的工况条件下具有极低的腐蚀速率,对孔蚀、缝隙腐蚀、接触腐蚀以及氢脆等也具有高的抵抗力; Ti-6Al-4V(TC4)合金表面的钝化膜在含H_2S腐蚀环境中更易遭到破坏,其稳定性会因温度变化与其他元素介入而发生变化,抗腐蚀性能也会随之发生改变。     

Corrosion resistance and mechanical properties of nickel-bearing ferritic stainless steels

Additions of nickel to ferritic steels containing 25–28% Cr and 2–4% Mo increased the impact toguhness especially when more than 2% Ni was present. The effect of nickel content increased up to 4% Ni, the largest addition studied. Steels stabilized with niobium had lower transition temperatures then did corresponding steels stablizied with titanium. Steels containing 4% Ni required annealing at 1050 C to avoid intermetalic compounds. It was also noted that nickel reduced the upper shelf energy in the Charpy impact test and eliminated a sharp transition from ductile to brittle behaviour. No definite effect of nickel on pitting potential was pound but steels in the series 25Cr-3.5 Mo-Ni-Ti consistenly had more noble pitting potentials and greater resistance to crevice corrosion than the 28 Cr-2Mo-Ni-Ti steels. Nickel contents of 1 or 2% tended to improve crevice corrosion resistance while larger nickel contents were somewhat ditrimental. Nickel strongly reduced critical current densities for passivity both in l N H₂SO₄ and in l N HCL and yielded corresponding increases in resistance to corrosion by these acids. Although 1% Ni or more caused the annealed steels to be susceptible to stress corrosion cracking in MgCl₂ boiling at 140 C, while the as-Welded steels containing 4% Ni did not crack in boiling 25% Nacl at pH 1.     

Numerical simulations study of the localized corrosion resistance of AISI 316L stainless steel and pure titanium in a simulated body fluid environment

The resistance of both AISI 316L stainless steel (AISI 316L SS) and commercially pure titanium (cpTi) to localized corrosion in a simulated body fluid solution was investigated using numerical simulations. The resulting model, based on transport equations in dilute solutions, is designed to predict the susceptibility of these two biomaterials to crevice corrosion initiation. The results show that cpTi and AISI 316L SS alloy are very resistant to the initiation of crevice corrosion in 0.9% NaCl solution and AISI 316L SS alloy is more susceptible to corrosion initiation over the long term than cpTi.     

Comparative In Vitro Study of Ti-12V-9Sn Shape Memory Alloy with C.P. Ti and Ti-12V Alloy for Potential Biomedical Application

The microstructure, mechanical properties, and electrochemical behavior of Ti-12V-9Sn shape memory alloy were investigated, with commercial pure titanium (C.P. Ti) and Ti-12V alloy as controls. The metastable β phase was partially retained and α″ martensite phase was obtained in Ti-12V-9Sn alloy, whereas only martensitic phases (α′ and α″) existed in Ti-12V alloy at room temperature. Ti-12V-9Sn alloy exhibited a good combination of strength and elongation, which showed a “double yield” feature, along with a complete shape recovery strain of 4%. The electrochemical measurements indicated that all of the experimental samples exhibited excellent corrosion resistance in the artificial saliva with and without 0.2% NaF, among which Ti-12V-9Sn alloy possessed the lowest corrosion current density in both kinds of simulated body fluids.     

超声波焊接制备功能梯度材料

采用超声波焊接的方法成功制备了功能梯度材料,它具有简便、环保、快速成型的特点.实验以铝合金6061、3003、纯钛、钛合金Ti-6Al-4V和纯镍为材料,利用超声波焊接方法制备Al/Ti/Ni功能梯度材料.通过金相显微分析、显微硬度分析、EDS分析对其焊接界面的微观结构、显微硬度、焊缝原子扩散程度进行测试和表征.结果表...     

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.