含碳化钨的耐磨添加剂制备及应用研究

发布时间：2018-04-23 02:23

本文选题：碳化钨 + 耐磨添加剂　；参考：《沈阳工业大学》2015年硕士论文

【摘要】：针对耐磨零部件在高强度、高硬度、高磨损等恶劣工况下服役寿命短的技术难题，采用了加入纳米WC陶瓷颗粒作为耐磨相的方法，，以提高耐磨件如截齿体的耐磨性。考虑到WC密度过大，熔炼过程中易产生偏析的特点，实验中将纳米级WC粉与其他金属粉料混合，压制成形，并经高温烧结制成耐磨添加剂。该添加剂能否有效解决成分偏析问题，需要通过熔炼浇铸后的样品来验证。试验中将该添加剂加入熔融钢水中，浇铸成铸钢件样品；采用不同热处理工艺处理后，对所得试样进行磨损试验、硬度测试和拉伸测试。采用X射线衍射、扫描电镜、能谱仪、场发射扫描电镜等设备，检测分析了耐磨添加剂的烧结产物和WC在铸钢中的分布。通过大量实验和分析总结得到如下实验结论：磨损实验结果证明，基体为40CrNi2Mo的铸钢样品中加入5%～8%的耐磨添加剂，磨损失重量比目前正在煤矿服役的截齿降低约12.8%，即耐磨性优于正在服役的截齿。微观组织检测分析表明，耐磨相WC主要分布于钢基体显微组织中，对提高耐磨性起着至关重要的作用；组织中的白色区域是以Fe，Si等元素的氧化物为主，同时含有少量WC和其他金属的小尺寸夹杂相；黑色区域氧化物较少。由于碳化钨与钢水之间具有良好的润湿性，因此在熔炼过程中很容易被周围的钢水包覆，从而成为钢水凝固的核心，有效细化了晶粒；在磨损试验中，被钢基组织牢固包覆的WC颗粒很难剥落，且自身的耐磨性很好。这种组织对提高耐磨性有重要作用。高密度耐磨相碳化钨在钢基组织中分布均匀，没有出现任何偏析现象；事实证明，通过制成添加剂方式将高密度组元加入钢中以避免重力偏析的方法取得了成功。本课题创造性的将该添加剂用于制造采煤机截齿的研究工作，并取得了较为有效的结果；改变了截齿体强调表面强化的传统思路。
[Abstract]:In order to improve the wear resistance of wear-resistant parts such as tooth cutters, the wear resistance of wear-resistant parts is improved by adding nano-WC ceramic particles as wear resistant phase, aiming at the short service life of wear-resistant parts under bad working conditions such as high strength, high hardness and high wear. Considering the characteristics of high WC density and easy segregation during melting, nano-WC powder was mixed with other metal powder in the experiment, compacted to form, and sintered at high temperature to make wear-resistant additive. Whether the additive can effectively solve the problem of composition segregation needs to be verified by melting and casting samples. The additive was added into molten steel and cast into steel castings. After different heat treatment, wear test, hardness test and tensile test were carried out. By means of X-ray diffraction, scanning electron microscope, energy spectrometer and field emission scanning electron microscope, the sintered products of wear-resistant additives and the distribution of WC in cast steel were examined and analyzed. Through a large number of experiments and analysis, the following experimental conclusions are obtained: the wear test results show that 5wt% wear-resistant additive is added to the cast steel sample with 40CrNi2Mo matrix. The loss weight of grinding is about 12. 8% lower than that of the cutting currently in service in coal mine, that is, the wear resistance is better than that of the gear in service. The microstructure analysis shows that the wear resistant phase WC mainly distributes in the microstructure of steel substrate, which plays an important role in improving the wear resistance, and the white area of the microstructure is mainly composed of the oxides of Fe, Si and other elements. Small size inclusions containing a small amount of WC and other metals, and less oxides in the black region. Because of the good wettability between tungsten carbide and molten steel, it is easy to be coated by the surrounding molten steel in the melting process, thus becoming the core of solidification of molten steel. The WC particles firmly coated with steel-based structure are difficult to peel off and have good wear resistance. This kind of structure plays an important role in improving wear resistance. The high density wear-resistant phase tungsten carbide distributes uniformly in the structure of steel without any segregation phenomenon, and it is proved that the method of adding high-density components into steel by making additives to avoid gravity segregation has been successful. In this paper, the additive is creatively used in the research of cutting teeth of shearer, and more effective results have been obtained, and the traditional thinking of tooth cutting body emphasizing surface strengthening has been changed.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ136.13

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