铁谱技术在判断发动机磨损状态中的应用研究

发动机中各摩擦副的工作环境恶劣,磨拟状态复杂,很难精确描述。而发动机所处的磨损状态是判断其是否正常工作的重要标准,因此建立发动机磨损状态监测具有重大的经济和社会效益。笔者利用铁谱技术作为一种监测手段,通过磨粒分析来判断发动机的磨损状态。     

XRF技术在设备磨损监测中的应用研究

通过对XRF分析技术在设备磨损状态监测中的应用历程、现状、特点的评述和分析,结合磨粒分析主要采用的铁谱和原子发射光谱的技术特点,提出了基于XRF技术的机械磨损状态监测策略,并对未来发展趋势做了展望,指出了亟待解决的问题.     

利用铁谱技术分析某柴油机的摩擦聚合物

发动机所处的磨损状态是判断其是否正常工作的一个重要的标准,其中各摩擦副的工作环境恶劣、磨损过程复杂,很难精确描述.在发动机磨损异常状态监测尤其要引起注意.文章利用铁谱技术对其润滑油变质产物--摩擦聚合物进行监测,通过磨粒分析来判断发动机的磨损状态.     

某型发动机组的磨损状况的模糊综合评判

提出了一种基于铁谱技术,结合层次分析法(AHP)和模糊数学的模糊综合评判方法。分析确定了发动机磨损状态评价因子的权重集以及评价因子的隶属函数,利用模糊综合评判法对发动机组的磨损状况进行了综合评价。评判计算结果表明了本文分析方法的合理性,且可信度较高。     

一种新型的铁谱检测技术

七十年代初期,国际上出现了一种新的检测技术——铁谱技术(Ferrography)。它是由美国麻省理工学院机械系的W.W.Seifert和美国Foxboro公司的V.C.West-colt共同研究而发表命名的。铁谱技术是一种以磨损微粒分析为基础的诊断技术。它用于观察发动机和其他部件的内部,而无需将各个工作零件打开或关闭就可以确定它们的磨损状况。铁谱技术的基本原理是,在不拆卸状态下抽取机械润滑油样,利用高梯度强磁场,将油样中所含的磨损微粒分离排谱,进行检测。以获得机械磨损的可靠信息,判断机械磨损的部位、性质和程度。铁谱仪器是实现铁谱技术的关键设备。目前有三种类型的仪器——分析铁谱仪,直     

透平机减速齿轮箱的在线铁谱监测

在线铁谱技术是一种由分析铁谱技术发展而来的磨损状态实时监测技术，对于连续运行的关键设备的主要摩擦付实施在线铁谱监测是十分必要的。它可以避免离线铁谱监测的取样、制样等繁杂过程和长间隔采样漏掉故障信息等缺点。利用在线铁谱技术对透平机减速齿轮箱的磨损状态监测结果表明，即使在正常磨损状态下，齿轮摩擦付的磨损速率并不是恒定的。它既受磨粒在摩擦付附近的不均匀造成的随机误差影响，又受齿轮载荷变化的影响。而磨损趋     

基于铁谱定量分析的齿轮箱磨损分析

铁谱定量分析能获得齿轮箱运行过程中的磨损量,主要指标为大磨粒读数DL和磨损烈度指数IS,并可将这两者绘制成趋势曲线。结合设备自身的故障率及铁谱数据的特点,对铁谱数据进行残差分析筛选合适数据,并改进传统的绝对值公式,计算出能反映齿轮箱运行情况的磨损状态界限值。在实际运用中,改进公式满足设备磨损状态的判断需求,及时反映齿轮箱当前运行状态的磨损情况,为设备故障预防的监测提供了一种方法。     

铁谱技术及其应用(一)

本文概述了铁谱技术的基本原理与特点,特别评价了其在机器状态监测方面的发展。简要介绍了铁谱仪的原理、结构以及磨损颗粒识别等方面的知识。并根据国内外有关资料及作者近年来的实践,结合典型实例分析,分别阐述了铁谱技术在摩擦学基础研究和摩擦学系统状态监测中的应用。主要内容包括:一、前言;二、铁谱技术的基本原理与特点;三、铁谱仪原理与结构;四、磨损颗粒识别与定量参数的选择;五、铁谱技术在摩擦学基础研究中的应用;六、铁谱技术在摩擦学系统状态监测中的应用;七、铁谱技术的发展趋势。     

基于铁谱技术的内燃机的应用研究

介绍了内燃机的磨损及典型磨粒特点,利用铁谱技术作为一种监测手段,通过磨粒分析来判断内燃机的磨损状态.     

采煤机截割部内漏水的危害性及治理

基于油液分析与铁谱技术,在线监测诊断采煤机截割部的润滑磨损故障。介绍采用铁谱技术定性定量测定润滑油中水分含量的方法;揭示截割部传动系统润滑条件恶化造成严重磨损及故障状态下磨损磨粒的宏微观特征;阐述润滑失效机制。分析内漏水对采煤机润滑系统危害的严重性,找出采煤机截割部内漏水源结点,采取治理措施,实际应用取得明显效果。     

Analysis for Wear Behaviors of Oxidative Wear

Sliding wear tests were performed for H13 steel and a cast steel under atmospheric conditions of 25, 200, and 400°C. XRD results identify that oxidative wear prevailed for the steels during sliding at 200–400°C. However, the oxidative wear at 200°C presented entirely different wear behaviors from the one at 400°C. With an increase of load, the oxidative wear at 200°C exhibited slowly increased and lower wear rates, despite relatively less tribo-oxides. On the contrary, although there were more tribo-oxides, the oxidative wear at 400°C presented rapidly increased and higher wear rates. The former oxidative wear could be classified into mild wear; the latter one fell beyond mild wear. The two types of oxidative wear universally existed; their discrepancies were mainly attributed not to the tribo-oxides, but to the extent of softening and deformation of substrate. Hence, we suggested that the two types of oxidative wear should be distinguished in the coming research, and were termed oxidative mild wear and oxidative wear, respectively.     

磨粒均匀涂布制谱方法研究

磨损微粒分离和收集是各种铁谱检测仪器的关键技术，文中提出了一种全新的均匀涂布制谱方法，磨粒不受挤压和碾磨作用，保持颗粒的原始信息。为此设计了磨粒制谱装置，并对样品制备，实验结果进行了分析和讨论。     

磨粒特征随滑动磨损进程的变化规律

为提高基于磨粒的机器状态监测的准确性,研究了磨粒特征随滑动磨损进程的变化规律.在球一盘磨损试验机上模拟可靠润滑和润滑不足2种工况下的摩擦磨损试验,分析了磨损过程中不同磨损阶段的磨粒尺寸分布和磨粒表面粗糙度,探讨了磨损进程中磨粒尺寸分布与磨粒表面粗糙度之间的关系.研究结果表明磨损进程中的磨粒特征的变化对机器状态监测极为有效.     

Transition of Mild Wear to Severe Wear in Oxidative Wear of H21 Steel

Under atmospheric conditions at 400 °C, we studied the wear mechanism of H21 steel with different tempering states as a function of normal load. Typical oxidative wear was identified by X-ray diffraction patterns with predominant tribo-oxides of Fe₃O₄ and Fe₂O₃. Under loads of 50–100 N, mild oxidative wear prevailed for all samples, such that the wear losses of H21 steel with various tempering states showed no significant differences with characteristics of a slight plastic deformation of the substrate and single-layer oxide. In this case, the wear rate was lower, and the tribo-oxide was decisive factor in determining wear rate. Under loads of 150–200 N, the transition of mild wear to severe wear occurred in H21 steel and was characterized by: (1) a significant difference of wear losses for steel with various tempering states; (2) wear loss that started to increase faster and reached a relatively high level; (3) the appearance of significant plastic deformation in the oxide underneath the substrate and multi-layer tribo-oxide. Under a load of 200 N for the steel tempered at 700 °C, plastic extrusion prevailed with a mixed metal-oxide layer.     

On Prediction of Wear Coefficients in Sliding Wear

The wear rates and wear coefficients of metals are analytically predicted based on the delamination theory of wear when the wear rates are controlled by the subsurface crack propagation rate. The wear rate and the wear coefficient are predicted to be directly proportional to the depth of crack location and the crack growth rate. The numerical values of wear coefficients are obtained through finite element analysis of crack propagation in elastoplastic solids. The agreement between typical experimental results and theoretical prediction is excellent.     

Prediction of Steady-State Wear Coefficients in Adhesive Wear

With an integrated adhesive wear model, Yang's second wear coefficient equation was previously found suitable for modeling the standard wear coefficients for both the transient wear and the steady-state wear of MMC-A, MMC-B, and MMC-C, which are aluminium-based matrix composites containing 10%, 15%, and 20% alumina particles, respectively. In this study, Yang's third wear coefficient equation was used to predict the standard wear coefficient and the net steady-state wear coefficient, respectively, for MMC-D, an aluminium alloy matrix composite containing 20% spherical alumina particles, and an aluminium alloy A6061-T6. As compared with the wear data obtained previously, the average deviations were found to be about 23% and 15%, respectively, for the predicted standard wear coefficients and about 20% and 65% for the predicted net steady-state wear coefficients for the two materials respectively. The high deviation of about 65% obtained for the aluminium alloy was due to the very low wear rate obtained during wear testing with a long sliding distance, with the presence of powdery debris.     

可共享的磨粒识别及磨损诊断系统

针对当前铁谱分析技术存在的不足 ,将计算机图像处理技术、数据库技术、网络通信技术相结合 ,提出了以人工智能、神经网络为核心的设计思想。介绍了基于本思想所建立的可共享的磨粒识别及磨损诊断系统WPRWDS,分析了其系统结构、实现机制、硬软件设计、功能和特点等。     

Modeling Wear State Evolution Using Real-Time Wear Debris Features

Because wear is one of the most typical causes of decreasing performance in running machines, monitoring wear is regarded as a crucial technology in maintaining the health of machines. However, monitoring wear is not a fully mature process because quantifying the development of wear in real time is a challenging task because there is no universal indicator. To meet this need, wear-oriented dynamic modeling with online ferrographic images was used to investigate and then describe a real-time wear state. This investigation was carried out by combining three wear indices to describe the wear rate, the wear mechanism, and the severity of wear. A binary classifier method is also proposed to classify these wear stages in the three extracted indices. A strategy to identify the dynamic transition of wear states with adaptive parameters is also developed and then a four-ball wear test is carried out to verify the method. The results indicate that this modeling strategy can accurately identify a developing wear state that is characterized by stages. This proposed method is better at monitoring the health evolution of a machine system than just detecting faults.     

柴油机主要摩擦副磨损型式的识别

本文首先提出了柴油机磨损型式识别的重要性,进而阐述了磨损型式模糊模式识别的过程,即：模糊模式识别原理,建立磨损型式的标准样板库,隶属函数的确定等等,最后给出了结论。     

Characteristics of Extrusive Wear and Transition of Wear Mechanisms in Elevated-Temperature Wear of a Carbon Steel

The dry sliding wear of a medium carbon steel with different microstructures was measured under the normal load range of 50–150 N at 400°C by a pin-on-disc high-temperature wear setup. The wear behavior and wear mechanism were systematically studied; in particular, the characteristics of extrusive wear and the transition of wear mechanisms were investigated. Under low normal loads, the wear is oxidative type wear. Once the normal load reached a critical value, a mild-to-severe wear transition occurred, and subsequently an extrusive wear prevailed. The mild-to-severe wear transition depended on the microstructure of matrix; the critical normal load of the transition was 112.5 N for tempered sorbite, 125 N for lamellar pearlite, and 137.5 N for tempered martensite and tempered troostite. As oxidative wear prevailed, a thick oxide layer about 20–30 μ m and a plate-like wear debris with regular outline were recognized. However, as the extrusive wear occurred, the wear rate abruptly increased but the friction coefficient was reduced. The extrusive wear predominated due to thermal softening of the matrix and presented a superthin oxide layer (less than 0.5 μ m) and low oxide content on worn surfaces, accompanied by the appearance of ribbon-like wear debris.