ISSN   1004-0595

CN  62-1224/O4

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不同岩石工况下新型高硬韧TBM刀圈用钢的磨损特性试验研究

Experimental Investigation on the Wear Characteristics of a Novel TBM Cutter Ring Material with High Hardness and High Toughness under Different Rock Conditions

  • 摘要: TBM刀圈的磨损性能不仅取决于刀圈自身的组织及性能,而且与岩石的类型以及磨损载荷紧密相关. 为此,选取了5种不同性能的刀圈钢,研究了磨损载荷以及岩石类型对试验钢磨损性能及磨损机制的影响. 研究结果表明:在砂岩工况下,不同性能试验钢均表现出微观切削磨损机制,随着试验钢硬度的增加,磨损量减小,磨屑由卷曲条带状转变为木屑状. 在花岗岩工况下,各试验钢磨损机制以犁削为主,磨屑呈粉末状或块状,磨损载荷较低时,耐磨性与试样硬度正相关,当磨损载荷增加到一定数值后,耐磨性同时取决于试验钢的硬度和韧性.

     

    Abstract: The wear resistance of TBM cutter ring material not only depends on its own microstructure and mechanical properties, but also closely related to the type of rock and wear load. Under different wear conditions, the wear mechanism of experimental steel with different mechanical properties is quite different, which leads to great changes in the wear resistance. TBM cutter ring material belongs to high alloy martensitic steel, its microstructure is composed of tempered martensite and carbide. The carbide with high hardness can ensure good wear resistance, while the hardness and impact toughness of TBM cutter ring steel can be adjusted effectively by tempered martensite. The tempering temperature and holding time is the main means to adjust the characteristics of tempered martensite. In this paper, five kinds of experimental steels with varying hardness and impact toughness gradient were prepared by different tempering treatment. The variation rules of wear resistance of experimental steels with different properties were studied under different wear loads and different rock types, and the wear morphologies of the wear surface and subsurface were observed and analyzed by scanning electron microscopy. The evolution of wear mechanism of experimental steels with different properties under different wear conditions was revealed. Specifically, the wear behavior of cutter ring steel with different mechanical properties under different types of rocks in real production process was simulated. The results showed that under the wear condition of sandstone, the wear mechanism of test steel with different mechanical properties was microscopic cutting. With the increase of hardness, the mass loss of specimens decreased, and the wear debris changed from strip to sawdust. The greater the wear load, the higher the wear mass loss of the test steel. Under the wear condition of granite, the wear mechanism of each test steel was mainly micro-ploughing and the wear resistance was positively correlated with hardness when the wear load was lower than 3 kN, and no crack appeared on the worn surface of each test steel. Meanwhile, the wear debris were powdery or block. When the load increased to 5000 N, crack gradually occured on the worn surface of experimental steel with the increase of hardness. For the cutter ring steel with toughness higher than 8 J, the wear mechanism was mainly micro-ploughing. When the toughness of the test steel was lower than 7 J, cracks appeared the worn surface, which resulted in a sharp weakening of the wear resistance of test steel. Therefore, when the load was higher then 3 kN, the wear resistance of the experimental steel depended on both hardness and toughness, and the experimental steel with good hardness and toughness had better wear resistance. The research on the wear behavior of cutter ring steel with different mechanical properties under different rock types provided a theoretical basis for the selection of cutter ring properties in practical application.

     

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