滚刀刀圈材料的激光熔覆硬度强化试验研究

Research on Hardness Strengthening Test of Laser Cladding for Hob Ring Material

摘要: 近年来，随着我国城市化进程的快速发展，土地资源短缺问题越来越明显，地下空间的开发显得越来越重要。盾构法以其对环境的干扰较小、效率较高、较为安全等特点成为隧道工程的首先考虑的施工方法。盾构机主要靠刀盘上的刀具进行挖掘作业，在硬岩地质下滚刀是主要的切削部件，因此需要刀圈具有足够的硬度进行破岩工作。其工作环境非常的恶劣，若经常更换刀圈会严重影响施工效率。基于此，本文中以激光熔覆技术对盾构机滚刀刀圈表面进行AlCoCrFeNi系列高熵合金加原位自生TiB₂作为增强相改性处理。通过试验确定了此系列合金粉末合适的热输入范围，结果表明，熔覆层硬度明显高于基材的硬度，提高了大约有337 HV2.0。

Abstract: In recent years, with the rapid development of China’s urbanization process, the shortage of land resources has become more and more obvious, and the development of underground space has become more and more important. The shield method has become the first considered construction method for tunnel engineering because of its characteristics of less interference to the environment, higher efficiency, and more safety. The shield machine mainly relies on the cutters on the cutter head for excavation operations. In hard rock geology, the hob is the main cutting component, so the cutter ring is required to have sufficient hardness for rock breaking work. The working environment is very harsh, and frequent replacement of the cutter ring will seriously affect the construction efficiency. Based on this, in this paper, laser cladding technology is used to modify the surface of the shield machine hob cutter ring with AlCoCrFeNi series high-entropy alloy plus in-situ TiB₂ as the reinforcing phase. The appropriate heat input range for this series of alloy powders was determined through experiments, and the results showed that the hardness of the cladding layer was significantly higher than that of the base material, increasing by about 337 HV2.0.