| 摘要: |
| 表面处理是提高机械零部件耐磨性能和使用寿命的有效方法。 针对某型号石油装备产品机械手抓手上使用的 40Cr 钢销轴,对表面分别采用镀锌处理和盐浴复合处理(Quench-polish-quench, QPQ),对比研究基体材料及两种不同表面处理后试样的球-平板往复干摩擦磨损行为,并对摩擦过程中产生的声发射信号进行记录和分析。 试验结果表明,QPQ 处理后表面硬度显著提高,深度方向的硬度分布满足设计要求,有效硬化层深度为 0. 3 mm。 各试样基体均为细小均匀的回火索氏体组织, 镀锌试样表面镀层厚度 25 μm,QPQ 处理的试样表面形成了氧化层+化合物层+扩散层组织。 两者摩擦因数曲线变化规律有一定差别,先上升后下降,随后达到稳定值。 镀锌试样摩擦因数更高,最大达到 0. 50,随后逐步稳定于 0. 36;而 QPQ 试样最高仅为 0. 18,并迅速达到稳定阶段至 0. 16。 同时,镀锌试样摩擦曲线上的微小波动更明显,摩擦过程不稳定程度更大。 镀锌试样表面磨痕的最大深度比 QPQ 试样稍小,但最大宽度更大,磨损体积更大。 声发射信号事件计数与摩擦因数之间存在相同的变化规律,即摩擦因数越高,声发射信号事件计数越多,信号数量与摩擦磨损的各阶段存在对应关系。 相对来说,镀锌试样的声发射信号事件计数更多,信号能量也更大。 |
| 关键词: 镀锌 Quench-polish-quench (QPQ) 处理 摩擦磨损 声发射 |
| DOI：10.11933/j.issn.1007-9289.20210305001 |
| 分类号:TH117 |
| 基金项目: |
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| Comparation of Friction Behavior Between Galvanized and QPQ Treated Pins |
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Li Jie1, Deng Yunzhe2, Zhou Bo3
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1.College of Mechanical Engineering, Hunan Institute of Engineering, Xiangtan 411104 , China;2.Sany Heavy Industry, Changsha 410100 , China;3.School of Locomotive and Vehicle, Hunan Railway Professional Technology College, Zhuzhou 412001 , China
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| Abstract: |
| As an effective way to improve the wear resistant property and service life of mechanical components, surface treatment has been widely used in industrial fields. Pins made of 40Cr steel, used on the grab of a certain type of petroleum equipment product manipulator, were galvanized and Quench-Polish-Quench (QPQ) treated, respectively. Then, dry friction behaviors in ball-on-plate reciprocating mode of base metal and two different surface treated samples were studied comparatively, and acoustic emission (AE) signals produced in the friction process were also recorded and analyzed. The results showed that the surface hardness of QPQ treated sample was significantly increased and the hardness distribution in depth direction met the design requirements, with effective hardening layer depth of 0. 3mm. Fine and uniform tempered sorbite were observed in base metal of all samples, with coating thickness of 25 μm for galvanized sample, and oxide layer+compound layer+diffusion layer for QPQ treated sample. The curves of coefficient of friction (CoF) vs. time of all samples illustrated different changing laws, increasing first and then decreasing to a stable value. The CoF of galvanized sample was higher, and the maximum value is 0. 50, then gradually stabilized at 0. 36; while the maximum value of QPQ treated sample was only 0. 18, and rapidly reached the stable stage to 0. 16. At the same time, the micro fluctuations on the friction curve of the galvanized sample was more obvious, showing greater instability in the friction process. The maximum depth of wear track of galvanized sample was slightly smaller than that of QPQ ones, with bigger maximum width and larger wear volume. Thehigher the CoF was, the more AE signal events were counted, demonstrating a corresponding relationship between the number of AE signal events and each stage of friction and wear. Relatively more AE signals and higher energy signals were monitored in friction process of galvanized sample than QPQ treated ones. |
| Key words: galvanized Quench-polish-quench (QPQ) treatment friction and wear acoustic emission (AE) |
