Performance improvement strategy of the TBM disc cutter ring material and evaluation of impact-sliding friction and wear performance

Abstract

Tunnel Boring Machine (TBM) cutter ring is prone to collapse, fracture, wear, and other types of failures when dealing with hard rock/extremely hard rock. In order to address the above issue, performance enhancement strategies including electroslag remelting and increased number of tempering cycles in the heat treatment process have been implemented. These strategies lead to improvements in the comprehensive performance of the cutter rings. To evaluate the effectiveness of these enhancements, a comparison was made between the mechanical properties of the cutter rings made by H13 and W360 steels, based on the parameters including microhardness, impact toughness, and impact-sliding resistance. The results show that the microhardness of W360 cutter ring specimen has increased by 9.99%, while the impact toughness has also increased by 54.2%. According to the impact-sliding wear experiment, the impact region of the W360 specimen has a smaller wear depth under the impact angles, reflecting that the impact resistance of the W360 specimen is better. However, when the impact angle is 60°, the wear volume of the sliding region of W360 specimen is larger than that of H13 specimen, which may be related to the fact that H13 specimen contains a higher proportion of martensite. To sum up, better comprehensive performance could be obtained by choosing a reasonable metallurgical method and an optimizing heat treatment process.