高钛钢在盐雾环境中的腐蚀行为

研究了高钛结构钢在室内盐雾干、湿循环加速腐蚀环境中的腐蚀行为,并与商用09CuPCrNi耐候钢和新型贝氏体耐候钢进行了对比。结果表明:高钛结构钢在腐蚀前期具有较好的耐腐蚀性能,但当腐蚀45 d后,锈层的保护能力逐渐弱于后两种钢的;因高钛钢具有均匀单一的显微组织,基体内部电位差较小,其初期腐蚀较缓慢;但当钢表面为锈层所覆盖后,因其腐蚀过于均匀,锈层与基体的界面平整,结合不牢固,锈层易脱落,其保护性随腐蚀时间的延长而逐渐减弱。     

无熔深堆焊铜技术研究

针对钢表面熔敷（覆）纯铜层，提出了“熔敷焊”工艺方法。金相和SEM检测表明：该工艺实现了钢基体与熔敷层的无熔深焊接，铜层与钢基体有良好的冶金结合，界面无未溶合、夹渣、气孔等缺陷。力学性能试验表明，焊接界面结合剪切强度超过了铜的强度。经能谱面、线扫描和成分分析表明，钢基体未发生熔化，基体与铜熔敷层的过渡区域宽仅几十微米，熔敷层中基体成分含量小于1％。     

热喷涂烧结涂层结合性能评价界面应力有限元分析

通过梯度液相烧结或中温反应烧结处理，热喷涂层具有很高的结合强度。采用线切割沿涂层／基体界面切成对称切口，两边黏结后直接拉伸的实验方法对此高强涂层抗拉结合强度进行评价。对应不同涂层材料和切口结构工艺参数，借助有限单元法对涂层／基体交界面上的应力分布及切口附近的应力集中进行了分析，为正确评价涂层／基体的结合强度提供了依据。     

微惯性开关制作过程中界面结合强度研究

在利用微电铸工艺制作惯性开关的过程中，经常会出现由于界面结合强度低而引起的铸层翘起问题。微电铸层与基板的界面结合强度低会降低微开关的制作成品率、延长制作周期、增加制作成本。针对这一问题，本文从界面钝化膜的角度，采用了“电解活化去除钝化膜”和“引入Cu过渡层”的方法。为探究钝化膜对界面结合强度的影响，通过Materials Studio软件对不同钝化膜去除率模型的界面结合能进行仿真计算，计算结果表明钝化膜去除率越高越有利于界面结合强度的提高，在完全去除钝化膜后界面结合强度提高了197%；为探究过渡金属对界面结合强度的影响，分别以Cu,Cr,Ti作为过渡层，与不锈钢基板和镍铸层建立结合层体系，计算体系的结合能，计算结果表明Cu与基板、Cu与铸层的结合能最高，与未引入过渡金属相比，引入Cu后界面结合强度提高了81%。在仿真研究结果的基础上，开展了电解活化实验，通过电解活化法去除了基板表面的钝化膜，实验结果表明：电解活化区域铸层的界面结合强度明显高于未活化区域铸层的界面结合强度；同时开展了铜过渡层实验，对比了有无Cu过渡层的界面结合强度，实验结果表明：引入Cu后，铸层的界面结合强度明显提高。在...     

无熔深堆焊铜技术研究

针对钢表面熔敷 (覆 )纯铜层 ,提出了“熔敷焊”工艺方法。金相和SEM检测表明 :该工艺实现了钢基体与熔敷层的无熔深焊接 ,铜层与钢基体有良好的冶金结合 ,界面无未溶合、夹渣、气孔等缺陷。力学性能试验表明 ,焊接界面结合剪切强度超过了铜的强度。经能谱面、线扫描和成分分析表明 ,钢基体未发生熔化 ,基体与铜熔敷层的过渡区域宽仅几十微米 ,熔敷层中基体成分含量小于 1%。     

温度对不锈钢/铝/不锈钢层状材料轧制复合行为的影响

研究了热轧复合不锈钢／铝／不锈钢层状材料的粘结行为，采用剥离试验、OM、SEM及EDAX等研究了坯料加热温度对界面粘结强度及特征的影响规律。结果表明：在523～773K范围内，粘结强度随着温度的升高而明显增加；温度低于523K时，铝／钢界面为机械结合状态，粘结强度低于7．8Nmm^-1，剥离断口位于其初始界面；温度高于673K后，界面达到近冶金结合状态，粘结强度超过20．3Nmm^-1,剥离断口几乎位于铝基体而非初始界面。钢层变形远小于铝层变形，界面两侧金属剪切流动导致的新表面接触及扩散行为是促使界面粘结的主要机制。     

复合材料界面断裂的光弹性研究

使用了光弹性方法初步研究了复合材料的界面断裂规律 ,观察了裂纹沿界面的扩展过程 ,界面的应力分布 ,并结合断裂力学方法计算了复合材料界面的脱粘强度。实验现象揭示了当裂纹扩展到界面附近时 ,若基体和增强项的强度都大于界面结合强度 ,裂纹前端的应力首先通过界面脱粘而释放掉一部分 ,裂纹越过基体先沿着界面扩展 ,达到一定程度后基体再发生基体裂纹扩展     

大气等离子喷涂Ni5Al/Al2O3-3％TiO2复合结构 涂层的显微组织与力学性能

采用大气等离子喷涂(APS)技术在6061铝合金基体表面预制Ni5Al合金黏结层,再在黏结层上喷涂Al_2O_3-3%TiO_2陶瓷层,研究了涂层的物相组成、微观形貌、显微硬度、结合强度、耐磨性能和耐腐蚀性能,分析了其拉伸断裂机理。结果表明:陶瓷层的物相主要由α-Al_2O_3、γ-Al_2O_3和锐钛矿型TiO_2组成;黏结层与基体以及黏结层与陶瓷层均形成了机械结合,但黏结层与基体的结合界面更致密;与基体相比,涂层的显微硬度更高、耐腐蚀性能和耐磨性能更优;涂层的结合强度低于黏结层的,其拉伸断裂位置多在黏结层和陶瓷层之间的界面处以及陶瓷层内部,界面处的拉伸断裂形式为混合断裂,黏结层上的为韧性断口,陶瓷层上的为脆性断口。     

马具基体材料及表面预处理对金刚石薄膜附着强度的影响

刀具基体材料的热膨胀系数以及金刚石薄膜与基体表面间的界面层和接触状态,是影响金刚石薄膜涂层刀具附着强度的主要因素。通过表面预处理和增加中间过渡层,可改变界面层结构、提高附着强度。适当粗糙的基体表面能与金刚石薄膜形成机械嵌合而使附着强度提高。     

刀具基体材料及表面预处理对金刚石薄膜附着强度的影响

刀具基体材料的热膨胀系数以及金刚石薄膜与基体表面间的界面层和接触状态,是影响金刚石薄膜涂层刀具附着强度的主要因素。通过表面预处理和增加中间过渡层,可改变界面层结构、提高附着强度。适当粗糙的基体表面能与金刚石薄膜形成机械嵌合而使附着强度提高。     

周浸加速循环腐蚀试验中耐候钢锈层的电化学特征

通过周浸加速腐蚀试验研究了耐候钢和碳钢在3．5％NaCl溶液中的腐蚀情况。试验结果表明：腐蚀200h的耐候钢表面生成的致密锈层主要由α-CrxFe1-xOOH组成。通过人工合成相应组分的腐蚀产物，并测试其离子选择性，发现该锈层有阳离子选择特性，能阻挡氯离子进入，降低钢的大气腐蚀速率；电化学交流阻抗（EIS）分析表明耐候钢的腐蚀过程主要由扩散控制。     

SO_2质量分数对污染海洋大气环境中高强钢E690腐蚀行为的影响

采用干湿交替腐蚀试验方法,结合电化学测试、锈层截面和腐蚀产物X射线衍射(X-ray diffraction,XRD)分析,研究SO_2质量分数对E690钢在模拟污染海洋大气环境中腐蚀行为的影响。结果表明,海洋大气环境中的SO_2改变了E690钢海洋大气腐蚀的电化学机制,使得极化曲线的阳极分支由弱钝化特征转变为活性溶解特征,阴极分支由氧扩散过程控制转变为氧扩散和析氢反应共同控制,因而大大促进了阳极和阴极的电化学反应过程。同时,SO_2又显著促进α-Fe OOH的生成和Ni、Cr合金元素在内锈层中的富集,大大促进锈层的致密化,使均匀腐蚀速率逐渐减低,并促进锈层底部点蚀坑的生长。随着模拟溶液中Na HSO_3浓度的增加,E690钢在60 d内的平均腐蚀速率逐渐增加,当Na HSO_3浓度达到0.03 mol/L时,又出现一定程度的降低;同时,锈层底部的点蚀坑随Na HSO_3浓度的增加显著长大。     

新型铁素体耐热钢在650℃的蠕变特性及氧化行为

应用电子探针、扫描电子显微镜和能谱仪等观察并分析了新型12%Cr铁素体耐热钢在650℃、120MPa蠕变后的组织和氧化层。结果表明:试验钢蠕变过程经历了3个阶段,在3 980h发生断裂;蠕变后,试验钢中的原板条马氏体组织消失,大量的M23C6粒子沿原奥氏体晶界长大并粗化,并在蠕变后期形成了Fe2(W,Mo)金属间化合物;在蠕变过程中试验钢表面形成了三层结构的氧化层,即以铬、锰和硅元素为主靠近基体的内层氧化物,以铁元素为主的中间层氧化物和以铬、锰和硅元素为主的最外层氧化物。     

Q345D低合金钢在海洋潮差区的腐蚀规律及电化学行为研究

通过在青岛海域2年实海挂片暴露试验研究Q345D低合金钢和对比材料Q235B普碳钢在潮差区的腐蚀行为。试验结果表明,Q345D钢在实海潮差区1年和2年周期的平均腐蚀速率都小于Q235B钢,且两种钢锈层组成和结构基本类似,但Q345D钢表面锈层较厚,且更致密均匀。通过室内模拟海水周浸腐蚀试验研究两种钢的初期腐蚀行为,通过腐蚀数据的回归拟合分析得出,在腐蚀起始阶段,Q345D钢与Q235B钢的腐蚀倾向差别不大,但随着周浸时间的延长,腐蚀速率逐渐降低,且Q345D钢表现出比Q235B更好的耐全面腐蚀性能。宏观电化学阻抗谱和微区阻抗谱测试结果也证实,Q345D低合金钢形成的腐蚀产物膜层具有比Q235B钢更高的膜层电阻,且能够在更短时间内形成稳定的腐蚀产物膜层。     

尖晶石—硼玻璃陶瓷内衬钢管的研究

采用Fe2O3-Al Na2B4O7系铝热离心法制备了陶瓷内衬钢管。研究了Na2B47添加剂对自蔓延过程和陶瓷致密化的影响。在自蔓延过程中,作为稀释剂存在的Na2B4O7,降低燃烧温度和燃烧速度,增加了陶瓷中FeAl2O4含量;Na2B4O7添加剂形成了玻璃相,延长了陶瓷的熔融期,可显著改善陶瓷致密度和内表面光整度;Na2B4O7添加剂作为除锈剂,促使过渡金属与钢管纹。对陶瓷层孔隙率和组织结构进行了分析,结果表明：陶瓷层由大量铁铝尘晶石（FeAl2O4),少量刚玉（Al2O3）以及基体玻璃相组成,孔隙率为4．6％。     

Contrasting Lubrication Properties of Imidazolium-Based Ionic Liquids Affected by the Nature of the Surface Under High Vacuum

The lubrication performance of imidazolium-based ionic liquids was evaluated under high vacuum using a ball-on-disk tribometer. A ball and a flat disk made of SUS440C stainless steel were used as specimens. A surface of the as-received flat disk specimen was covered with a thick oxide layer (>40 nm). For an examination of the effect of the surface oxide layer on the tribological performance of the ionic liquids under high vacuum, another specimen with a thin oxide layer (approx. 4 nm thick) was prepared. The ionic liquids with the TFSA anion showed better lubrication performance with the thicker oxide layer specimen, whereas the ionic liquids with the BF4 anion showed superior performance with the thinner oxide layer specimen. These results are discussed based on the HSAB principle. It is shown that the mechanism of the opposite tribological characteristics can be reasonably explained in terms of the chemical hardness by the HSAB principle.     

Low-friction tribofilm formed by the reaction of ZDDP on iron oxide

An iron oxide layer (mixture of Fe₃O₄ and FeO) was formed by water-vapor treatment on tool steel plates. Bearing steel cylinders were slid against the plates in PAO with and without 1% zinc dialkyldithiophosphate (ZDDP) at 80 °C. The friction coefficient was below 0.06–0.08 with ZDDP, which is more than 20% lower than that without ZDDP and about a half of a steel/steel contact under the same condition. The formation of multi-layered tribofilm of 30–130 nm on the iron oxide was identified by TEM. The bottom part of the tribofilm is a layer of 10–30 nm that contains Zn, Fe, S, P, and O with a gradient composition, where distribution peaks of Zn and S were found by EDX.     

Effect of Surface Oxide Layer of Steel on the Tribological Characteristics of Load-bearing Additives for Multiply-Alkylated Cyclopentane Oil under High Vacuum

The tribological performance of two types of additives—alkylated phenyl phosphate and lead naphthenate—dissolved in multiply-alkylated cyclopentane was evaluated under a high vacuum using two types of ball-on-disk tribometers: a reciprocating motion tribometer under mild loading conditions and a unidirectional rotating motion tribometer under heavy loading conditions. A ball and a flat disk made of SUS440C stainless steel were used as specimens for both tribometers. The surface of the as-received flat disk specimen was covered with a thick (>40 nm) oxide layer. For the examination of the effect of the surface oxide layer on the tribological performance of the liquid lubricants under a high vacuum, another specimen with an oxide layer (approx. 4 nm thick) was prepared. The alkylated phenyl phosphate additive showed better lubrication performance with the specimen with the thicker oxide layer, but the lead naphthenate additive showed superior performance with the thinner oxide layer specimen. It is also shown that these opposite tribological characteristics are explained by the hard and soft acids and bases principle.     

The effect of temperature on the unlubricated sliding wear of 5 CrNiMo steel against 40 MnB steel in the range 400–600°C

5 CrNiMo steel is used traditionally as hot forging die material in China. High temperature wear is a common failure mode of the steel. This paper deals with the sliding wear behavior of the steel in the temperature range 400°C to 600°C. The composition and features of the worn surface were analyzed using SEM, EDS and XRD. The oxidation of 5 CrNiMo steel under sliding wear condition at elevated temperature indicated that the oxide transfer layer formed on the sliding surface consisted of Fe₃O₄ and Fe₂O₃. The wear mechanism changed with the test temperature and the oxide transfer layer played an important part in the change in wear mechanism. At lower temperatures, wear was due to abrasive wear. From 500°C to 550°C, the oxide transfer layer presented a relatively compact morphology and the oxidational wear was the principal wear mechanism resulting in low wear rate at 500°C. When the test temperature was at 600°C, adhesive wear was predominant, and the wear rate increased greatly.     

不锈钢系统“红锈”形成的因素及消除方法——ASME BPE非强制性附录D的介绍与解读

依据ASME BPE—2012非强制性附录D对＂红锈＂与＂不锈钢＂进行了节译,专门介绍和解读了附录D关于在不锈钢高纯净系统中＂红锈＂形成的因素和消除方法。