爆炸硬化处理对高锰钢冲击磨损性能影响的研究

对Mn13Cr2高锰钢进行了爆炸硬化处理。并分别以玻璃砂、鹅卵石为磨料，在MLD．10动载磨料磨损试验机上对比研究了爆炸前、后Mn13Cr2高锰钢的冲击磨损性能。实验结果表明：在低硬度磨料（玻璃砂）冲击磨损时，爆炸硬化使高锰钢的冲击耐磨性提高20％-40％。在高硬度磨料（鹅卵石）冲击磨损时，在冲击功小于1．7J的条件下，爆炸硬化使高锰钢的冲击耐磨性提高30—50％。在冲击功大予1．7J的条件下，爆炸硬化则使高锰钢的冲击耐磨性降低。爆炸硬化使高锰钢表层硬化和冲击韧性降低是冲击耐磨性发生变化的主要原因。在冲击磨损条件下，爆炸硬化前、后高锰钢磨损面均出现磨料嵌入物及犁沟、凿削坑和剥落坑等形貌特征。爆炸硬化高锰钢适用予低硬度磨料的冲击磨损及高硬度磨料的低冲击功冲击磨损的工况条件。     

热轧奥氏体中锰耐磨钢的磨料磨损性能研究

以热轧BTW中锰钢板为实验材料,借助ML-100磨料磨损试验机,研究以煤泥粉为软质磨料和石英砂为硬质磨料时其磨料磨损性能,利用SEM分析其磨损机制。实验结果表明,软质磨料磨损工况条件下,热轧奥氏体中锰钢和高锰钢的相对耐磨性低于马氏体耐磨钢,硬质磨料磨损工况条件下,热轧奥氏体中锰钢的相对耐磨性高于高锰钢和马氏体耐磨钢,因此热轧中锰钢更适用于硬质磨料磨损工况;无论软质和硬质磨料磨损工况,热轧中锰钢的加工硬化均高于热轧高锰钢,表现出更好的加工硬化性能。煤泥粉软质磨料对热轧中锰钢的磨损机制表现为微观切削磨损,伴随局部的疲劳剥落;石英砂硬质磨料对热轧中锰钢的磨损机制则为典型的凿削磨损和微观切削磨损。     

钢在湿磨蚀条件下的耐磨性

本文对不同热处理的22种钢在湿磨料磨蚀条件下的耐磨性及其规律性进行了研究,认为: 1.钢在不同应力的湿磨蚀条件下,其耐磨性是不同的; 2.在尖锐湿磨料磨蚀条件下,钢的耐磨性与含碳量及硬度有关,大块磁化物能使耐磨性明显地提高; 3.在圆角湿磨料磨蚀条件下,钢的耐磨性与含碳量及硬度几乎无关。如含铬量达13%左右或更高时,耐磨性明显提高,说明腐蚀起主要作用。含锰量高的钢,将明显削弱其耐磨性; 4.无论在尖锐或圆角湿磨料磨蚀条件下,高锰钢并不显示其良好的耐磨性,甚至在低应力条件下它是最差的; 5.提出了钢的湿磨蚀机理模型。     

碳对中高碳Cr—Mn低合金钢耐磨性影响的研究

研究了中高碳Cr-Mn低合金钢在淬硬状态下碳对不同磨损条件下耐磨性的影响。结果表明,在无冲击磨料磨损条件下,碳量增加,耐磨性提高;在有冲击磨料磨损情况下,则呈相反的趋势;在腐蚀磨料磨损的条件下,碳的影响因介质的pH值而异。根据磨损机制,分析了碳量的变化改变了组织组成和性能,因而使耐磨性有变化。     

两种不同组织类型相同强度级别低合金高强钢的耐磨性

利用摩擦磨损试验机和自由磨料式腐蚀磨损试验机,在不同的润滑、载荷和腐蚀条件下,对两种组织类型不同、但抗拉强度同为700 MPa级别的S700和M700低合金高强度钢的滑动耐磨性和腐蚀耐磨性进行了研究,并分析了磨损机理。结果表明:S700钢的组织为铁素体+贝氏体,M700钢的组织为铁素体+珠光体;S700钢的硬度略高于M700钢的;在相同的滑动磨损条件下,S700钢的磨损量小于M700钢的;试验钢在酸性溶液中的腐蚀耐磨性均较差;在相同的腐蚀磨损条件下,S700钢的腐蚀耐磨性优于M700钢的;两种试验钢的滑动磨损机制主要是微观切削和塑性变形,酸性条件下的腐蚀磨损形貌为大面积的腐蚀坑且伴随剥落,而碱性条件的则以微观切削为主,并伴有少许的剥落。     

铸态高铬铸铁柱状晶粒区耐磨性研究

在二体磨料磨损系统中,使用不同硬度的磨料研究了２８％Ｃｒ铸铁柱状晶粒区不同方向上的耐磨性。结果表明,碳化物位向对铸铁耐磨性的影响与磨料硬度有关。使用硬磨料时碳化物位向对铸铁耐磨性的影响很小,使用中等硬度的磨料时碳化物纤维垂直于磨损面排列会降低铸铁的耐磨性,当使用低硬度磨料,碳化物纤维垂直于磨损面排列时才显著提高铸铁的耐磨性。     

分散镶铸工艺提高高锰钢耐磨性研究

采用分散镶铸工艺在高锰钢铸件内镶铸网状弹簧钢丝骨架,浇注高锰钢复合材料试棒。采用金相、硬度试验、电子探针等手段对复合材料的组织和性能进行了分析。结果表明,分散镶铸后,６５Ｍｎ钢丝在高锰钢铸件内部产生了良好的冶金结合,水韧处理后形成了网状纤维马氏体组织,从而提高高锰钢件在低应力磨料磨损条件下的耐磨性。     

一种新型奥氏体耐磨钢

高锰钢(ZGMn13)长期来用于制作矿山机械、建材机械、电力机械中承受冲击磨料磨损的零件,使用很广泛。许多工况条件下由于冲击不强,加工硬化效果不好,使用后磨损表面硬度不高,不能形成高硬度的硬化层。工件表面迅速被磨损。本文介绍的是一种具有高塑性、韧性、好的强度,加工硬化能力更强,在冲击磨料磨损的条件下较ZG-Mn13的耐磨性更高的材料。     

热轧高锰钢Mn13的冲滚磨料磨损性能

在M2000摩擦磨损试验机上,研究以煤矸石为磨料时热轧高锰钢Mn13冲滚耦合的磨料磨损性能,利用XRD和SEM分析其组织转变及磨损机制。实验结果表明,在较高冲滚载荷下,热轧Mn13钢表现出更好的抗冲滚磨料磨损性能;冲滚磨料磨损表面存在一定厚度的硬化层,且随冲滚载荷的增加,磨损面硬度增加,硬化层厚度增大,形变孪晶和马氏体相变是其加工硬化和耐磨损性能改善的主要原因;低载荷冲击时,磨损机制主要表现为凿削磨损并伴随犁沟切削磨损,较高载荷冲击时,磨损机制凿削磨损和犁沟划伤过渡到疲劳剥落和凿削磨损。     

30CrMnSi钢的动载磨料磨损

对30CrMnSi钢的动载磨料磨损试验研究指出,30CrMnSi钢的淬火组织具有较高耐磨性。但在不同冲击功下,当冲击功为1.2J时,耐磨性出现了峰值,经与高锰钢的耐磨特性相比表明,在轻、中等载荷冲击下,该钢可以取代高锰钢。     

陶瓷刀具高效干车削冷轧辊的刀具磨损机理

采用陶瓷刀具干车削硬态条件下的冷轧辊,分析了不同切削条件下陶瓷刀具的寿命、刀具磨损形态,并分析了裂纹、剥落和崩刃过程。试验和理论分析证实:陶瓷刀具高效切削冷轧辊时,裂纹的生成和扩展是造成刀具失效的主要磨损机理。     

Effect of Cold Rolling on the Fretting Wear Behavior and Mechanism in Inconel 690 Alloy

The influence of cold rolling on the fretting wear behavior and mechanism of Inconel 690 alloy at 320?°C in air was studied. The wear volume and worn surface were obtained and analyzed using laser scanning confocal microscopy, electron back-scattering diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The grinding surface and strain distribution were also studied by electron back-scattering diffraction to analyze the mechanism of fretting damage. The results indicated that with an increase in cold rolling reduction, the microhardness was increased. However, the friction coefficient and wear volume first increased and then decreased. The characteristics of fretting areas changed from a gross slip regime to a partial slip regime. Accordingly, the damage mechanism in the gross slip regime was a combination of oxidative wear, abrasive wear, and delamination, whereas the damage mechanism in the partial slip regime was mainly adhesive wear.     

带钢冷轧机工作辊表面粗糙峰轧制磨损过程离散元法研究

将带钢冷轧过程中磨损量仅有微米或亚微米数量级的工作辊表面粗糙峰的轧制磨损,视作一种由更小尺度的微细颗粒质量脱落引起的不连续细观磨损行为,建立工作辊表面局部区域内粗糙峰轧制磨损的离散元仿真模型,模拟研究工作辊表面粗糙峰上质量脱落的变化过程和磨损规律。针对工业生产中使用电火花毛化机床加工制备的实际工作辊表面微观形貌,抽象建立若干种主要工作辊表面粗糙峰几何形状,研究不同几何形态粗糙峰的表面在相同的轧制工况条件下的不同磨损行为和抗磨损性能,仿真结果与工业生产中实测取得的工作表面粗糙峰磨损规律定性一致。研究也表明,模拟工作辊表面粗糙峰的复杂细观磨损问题,离散元方法可能是一种值得关注的方法。     

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。